DataGridViewComboBoxColumn Clase

Definición

public ref class DataGridViewComboBoxColumn : System::Windows::Forms::DataGridViewColumn

[System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewComboBoxColumn), "DataGridViewComboBoxColumn.bmp")]
public class DataGridViewComboBoxColumn : System.Windows.Forms.DataGridViewColumn

[System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewComboBoxColumn), "DataGridViewComboBoxColumn")]
public class DataGridViewComboBoxColumn : System.Windows.Forms.DataGridViewColumn

[<System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewComboBoxColumn), "DataGridViewComboBoxColumn.bmp")>]
type DataGridViewComboBoxColumn = class
    inherit DataGridViewColumn

[<System.Drawing.ToolboxBitmap(typeof(System.Windows.Forms.DataGridViewComboBoxColumn), "DataGridViewComboBoxColumn")>]
type DataGridViewComboBoxColumn = class
    inherit DataGridViewColumn

Public Class DataGridViewComboBoxColumn
Inherits DataGridViewColumn

Herencia

Object

DataGridViewElement

DataGridViewBand

DataGridViewColumn

DataGridViewComboBoxColumn

Atributos

ToolboxBitmapAttribute

Ejemplos

En el ejemplo de código siguiente se muestra cómo usar un DataGridViewComboBoxColumn para ayudar a introducir datos en la TitleOfCourtesy columna.

#using <System.Data.dll>
#using <System.Windows.Forms.dll>
#using <System.dll>
#using <System.Drawing.dll>

#using <System.Xml.dll>
#using <System.EnterpriseServices.dll>
#using <System.Transactions.dll>
using namespace System;
using namespace System::Data;
using namespace System::Data::SqlClient;
using namespace System::Windows::Forms;
using namespace System::Collections::Generic;
using namespace System::Drawing;

public ref class Employees : public Form
{
private:
    DataGridView^ DataGridView1;

private:
    DataGridView^ DataGridView2;

public:
    [STAThread]
    static void Main()
    {
        try
        {
            Application::EnableVisualStyles();
            Application::Run(gcnew Employees());
        }
        catch (Exception^ e)
        {
            MessageBox::Show(e->Message + e->StackTrace);
        }
    }

private:
    Dictionary<String^, bool>^ inOffice;

public:
    Employees()
    {
        DataGridView1 = gcnew DataGridView();
        DataGridView2 = gcnew DataGridView();
        connectionString =
            "Integrated Security=SSPI;Persist Security Info=False;" +
            "Initial Catalog=Northwind;Data Source=localhost";
        inOffice = gcnew Dictionary<String^, bool>;

        this->Load += gcnew EventHandler(this, &Employees::Form1_Load);
    }

private:
    void Form1_Load(System::Object^ /*sender*/, System::EventArgs^ /*e*/)
    {
        try
        {
            SetUpForm();
            SetUpDataGridView1();
            SetUpDataGridView2();
        }
        catch (SqlException^)
        {
            MessageBox::Show("The connection string <"
                + connectionString
                + "> failed to connect.  Modify it "
                + "to connect to a Northwind database accessible to "
                + "your system.",
                "ERROR", MessageBoxButtons::OK, MessageBoxIcon::Exclamation);
            Application::Exit();
        }
    }

private:
    void SetUpForm()
    {
        Size = System::Drawing::Size(800, 600);
        FlowLayoutPanel^ flowLayout = gcnew FlowLayoutPanel();
        flowLayout->FlowDirection = FlowDirection::TopDown;
        flowLayout->Dock = DockStyle::Fill;
        Controls->Add(flowLayout);

        flowLayout->Controls->Add(DataGridView1);
        flowLayout->Controls->Add(DataGridView2);
    }

private:
    void SetUpDataGridView2()
    {
        DataGridView2->Dock = DockStyle::Bottom;
        DataGridView2->TopLeftHeaderCell->Value = "Sales Details";
        DataGridView2->RowHeadersWidthSizeMode = 
            DataGridViewRowHeadersWidthSizeMode::AutoSizeToAllHeaders;
    }

private:
    void SetUpDataGridView1()
    {
        //DataGridView1.DataError += new 
          //  DataGridViewDataErrorEventHandler(DataGridView1_DataError);
        DataGridView1->CellContentClick += gcnew 
            DataGridViewCellEventHandler(this, &Employees::DataGridView1_CellContentClick);
        DataGridView1->CellValuePushed += gcnew 
            DataGridViewCellValueEventHandler(this, &Employees::DataGridView1_CellValuePushed);
        DataGridView1->CellValueNeeded += gcnew 
            DataGridViewCellValueEventHandler(this, &Employees::DataGridView1_CellValueNeeded);

        // Virtual mode is turned on so that the
        // unbound DataGridViewCheckBoxColumn will
        // keep its state when the bound columns are
        // sorted.       
        DataGridView1->VirtualMode = true;
        DataGridView1->AutoSize = true;
        DataGridView1->DataSource = Populate("SELECT * FROM Employees");
        DataGridView1->TopLeftHeaderCell->Value = "Employees";
        DataGridView1->RowHeadersWidthSizeMode = 
            DataGridViewRowHeadersWidthSizeMode::AutoSizeToAllHeaders;
        DataGridView1->ColumnHeadersHeightSizeMode = 
            DataGridViewColumnHeadersHeightSizeMode::AutoSize;
        DataGridView1->AutoSizeColumnsMode = 
            DataGridViewAutoSizeColumnsMode::AllCells;
        DataGridView1->AllowUserToAddRows = false;
        DataGridView1->AllowUserToDeleteRows = false;

        // The below autogenerated column is removed so 
        // a DataGridViewComboboxColumn could be used instead.
        DataGridView1->Columns->Remove(ColumnName::TitleOfCourtesy.ToString());
        DataGridView1->Columns->Remove(ColumnName::ReportsTo.ToString());

        AddLinkColumn();
        AddComboBoxColumns();
        AddButtonColumn();
        AddOutOfOfficeColumn();
    }

private:
    void AddComboBoxColumns()
    {
        DataGridViewComboBoxColumn^ comboboxColumn;
        comboboxColumn = CreateComboBoxColumn();
        SetAlternateChoicesUsingDataSource(comboboxColumn);
        comboboxColumn->HeaderText = "TitleOfCourtesy (via DataSource property)";
        DataGridView1->Columns->Insert(0, comboboxColumn);

        comboboxColumn = CreateComboBoxColumn();
        SetAlternateChoicesUsingItems(comboboxColumn);
        comboboxColumn->HeaderText = "TitleOfCourtesy (via Items property)";
        // Tack this example column onto the end.
        DataGridView1->Columns->Add(comboboxColumn);
    }

private:
    void AddLinkColumn()
    {
        DataGridViewLinkColumn^ links = gcnew DataGridViewLinkColumn();

        links->UseColumnTextForLinkValue = true;
        links->HeaderText = ColumnName::ReportsTo.ToString();
        links->DataPropertyName = ColumnName::ReportsTo.ToString();
        links->ActiveLinkColor = Color::White;
        links->LinkBehavior = LinkBehavior::SystemDefault;
        links->LinkColor = Color::Blue;
        links->TrackVisitedState = true;
        links->VisitedLinkColor = Color::YellowGreen;

        DataGridView1->Columns->Add(links);
    }

private:
    void SetAlternateChoicesUsingItems(
        DataGridViewComboBoxColumn^ comboboxColumn)
    {
        comboboxColumn->Items->AddRange("Mr.", "Ms.", "Mrs.", "Dr.");
    }

private:
    DataGridViewComboBoxColumn^ CreateComboBoxColumn()
    {
        DataGridViewComboBoxColumn^ column =
            gcnew DataGridViewComboBoxColumn();
        {
            column->DataPropertyName = ColumnName::TitleOfCourtesy.ToString();
            column->HeaderText = ColumnName::TitleOfCourtesy.ToString();
            column->DropDownWidth = 160;
            column->Width = 90;
            column->MaxDropDownItems = 3;
            column->FlatStyle = FlatStyle::Flat;
        }
        return column;
    }

private:
    void SetAlternateChoicesUsingDataSource(DataGridViewComboBoxColumn^ comboboxColumn)
    {
        {
            comboboxColumn->DataSource = RetrieveAlternativeTitles();
            comboboxColumn->ValueMember = ColumnName::TitleOfCourtesy.ToString();
            comboboxColumn->DisplayMember = comboboxColumn->ValueMember;
        }
    }

private:
    DataTable^ RetrieveAlternativeTitles()
    {
        return Populate("SELECT distinct TitleOfCourtesy FROM Employees");
    }

    String^ connectionString;

private:
    DataTable^ Populate(String^ sqlCommand)
    {
        SqlConnection^ northwindConnection = gcnew SqlConnection(connectionString);
        northwindConnection->Open();

        SqlCommand^ command = gcnew SqlCommand(sqlCommand, northwindConnection);
        SqlDataAdapter^ adapter = gcnew SqlDataAdapter();
        adapter->SelectCommand = command;

        DataTable^ table = gcnew DataTable();
        adapter->Fill(table);

        return table;
    }

    // Using an enum provides some abstraction between column index
    // and column name along with compile time checking, and gives
    // a handy place to store the column names.
    enum class ColumnName
    {
        EmployeeID,
        LastName,
        FirstName,
        Title,
        TitleOfCourtesy,
        BirthDate,
        HireDate,
        Address,
        City,
        Region,
        PostalCode,
        Country,
        HomePhone,
        Extension,
        Photo,
        Notes,
        ReportsTo,
        PhotoPath,
        OutOfOffice
    };

private:
    void AddButtonColumn()
    {
        DataGridViewButtonColumn^ buttons = gcnew DataGridViewButtonColumn();
        {
            buttons->HeaderText = "Sales";
            buttons->Text = "Sales";
            buttons->UseColumnTextForButtonValue = true;
            buttons->AutoSizeMode =
                DataGridViewAutoSizeColumnMode::AllCells;
            buttons->FlatStyle = FlatStyle::Standard;
            buttons->CellTemplate->Style->BackColor = Color::Honeydew;
            buttons->DisplayIndex = 0;
        }

        DataGridView1->Columns->Add(buttons);

    }

private:
    void AddOutOfOfficeColumn()
    {
        DataGridViewCheckBoxColumn^ column = gcnew DataGridViewCheckBoxColumn();
        {
            column->HeaderText = ColumnName::OutOfOffice.ToString();
            column->Name = ColumnName::OutOfOffice.ToString();
            column->AutoSizeMode = 
                DataGridViewAutoSizeColumnMode::DisplayedCells;
            column->FlatStyle = FlatStyle::Standard;
            column->ThreeState = true;
            column->CellTemplate = gcnew DataGridViewCheckBoxCell();
            column->CellTemplate->Style->BackColor = Color::Beige;
        }

        DataGridView1->Columns->Insert(0, column);
    }

private:
    void PopulateSales(DataGridViewCellEventArgs^ buttonClick)
    {

        String^ employeeID = DataGridView1->Rows[buttonClick->RowIndex]
            ->Cells[ColumnName::EmployeeID.ToString()]->Value->ToString();
        DataGridView2->DataSource = Populate("SELECT * FROM Orders WHERE EmployeeID = " + employeeID);
    }

    #pragma region "SQL Error handling"
private:
    void DataGridView1_DataError(Object^ sender, DataGridViewDataErrorEventArgs^ anError)
    {

        MessageBox::Show("Error happened " + anError->Context.ToString());

        if (anError->Context == DataGridViewDataErrorContexts::Commit)
        {
            MessageBox::Show("Commit error");
        }
        if (anError->Context == DataGridViewDataErrorContexts::CurrentCellChange)
        {
            MessageBox::Show("Cell change");
        }
        if (anError->Context == DataGridViewDataErrorContexts::Parsing)
        {
            MessageBox::Show("parsing error");
        }
        if (anError->Context == DataGridViewDataErrorContexts::LeaveControl)
        {
            MessageBox::Show("leave control error");
        }

        if (dynamic_cast<ConstraintException^>(anError->Exception) != nullptr)
        {
            DataGridView^ view = (DataGridView^)sender;
            view->Rows[anError->RowIndex]->ErrorText = "an error";
            view->Rows[anError->RowIndex]->Cells[anError->ColumnIndex]->ErrorText = "an error";

            anError->ThrowException = false;
        }
    }
    #pragma endregion

private:
    void DataGridView1_CellContentClick(Object^ /*sender*/, DataGridViewCellEventArgs^ e)
    {

        if (IsANonHeaderLinkCell(e))
        {
            MoveToLinked(e);
        }
        else if (IsANonHeaderButtonCell(e))
        {
            PopulateSales(e);
        }
    }

private:
    void MoveToLinked(DataGridViewCellEventArgs^ e)
    {
        String^ employeeId;
        Object^ value = DataGridView1->Rows[e->RowIndex]->Cells[e->ColumnIndex]->Value;
        if (dynamic_cast<DBNull^>(value) != nullptr) { return; }

        employeeId = value->ToString();
        DataGridViewCell^ boss = RetrieveSuperiorsLastNameCell(employeeId);
        if (boss != nullptr)
        {
            DataGridView1->CurrentCell = boss;
        }
    }

private:
    bool IsANonHeaderLinkCell(DataGridViewCellEventArgs^ cellEvent)
    {
        if (dynamic_cast<DataGridViewLinkColumn^>(DataGridView1->Columns[cellEvent->ColumnIndex]) != nullptr
             &&
            cellEvent->RowIndex != -1)
        { return true; }
        else { return false; }
    }

private:
    bool IsANonHeaderButtonCell(DataGridViewCellEventArgs^ cellEvent)
    {
        if (dynamic_cast<DataGridViewButtonColumn^>(DataGridView1->Columns[cellEvent->ColumnIndex]) != nullptr
             &&
            cellEvent->RowIndex != -1)
        { return true; }
        else { return (false); }
    }

private:
    DataGridViewCell^ RetrieveSuperiorsLastNameCell(String^ employeeId)
    {

        for each (DataGridViewRow^ row in DataGridView1->Rows)
        {
            if (row->IsNewRow) { return nullptr; }
            if (row->Cells[ColumnName::EmployeeID.ToString()]->Value->ToString()->Equals(employeeId))
            {
                return row->Cells[ColumnName::LastName.ToString()];
            }
        }
        return nullptr;
    }

    #pragma region "checkbox state"

private:
    void DataGridView1_CellValuePushed(Object^ sender,
        DataGridViewCellValueEventArgs^ e)
    {
        if (IsCheckBoxColumn(e->ColumnIndex))
        {
            String^ employeeId = GetKey(e);
            if (!inOffice->ContainsKey(employeeId))
            {
                inOffice->Add(employeeId, (Boolean)e->Value);
            }
            else
            {
                inOffice[employeeId] = (Boolean)e->Value;
            }
        }
    }

private:
    String^ GetKey(DataGridViewCellValueEventArgs^ cell)
    {
        return DataGridView1->Rows[cell->RowIndex]->
            Cells[ColumnName::EmployeeID.ToString()]->Value->ToString();
    }

private:
    void DataGridView1_CellValueNeeded(Object^ sender,
        DataGridViewCellValueEventArgs^ e)
    {

        if (IsCheckBoxColumn(e->ColumnIndex))
        {
            String^ employeeId = GetKey(e);
            if (!inOffice->ContainsKey(employeeId))
            {
                bool defaultValue = false;
                inOffice->Add(employeeId, defaultValue);
            }

            e->Value = inOffice[employeeId];
        }
    }

private:
    bool IsCheckBoxColumn(int columnIndex)
    {
        DataGridViewColumn^ outOfOfficeColumn =
            DataGridView1->Columns[ColumnName::OutOfOffice.ToString()];
        return (DataGridView1->Columns[columnIndex] == outOfOfficeColumn);
    }
    #pragma endregion
};

int main()
{
    Employees::Main();
}

using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;
using System.Collections.Generic;
using System.Drawing;

public class Employees : Form
{
    private DataGridView DataGridView1 = new DataGridView();
    private DataGridView DataGridView2 = new DataGridView();

    [STAThread]
    public static void Main()
    {
        try
        {
            Application.EnableVisualStyles();
            Application.Run(new Employees());
        }
        catch (Exception e)
        {
            MessageBox.Show(e.Message + e.StackTrace);
        }
    }

    public Employees()
    {
        this.Load += new EventHandler(Form1_Load);
    }

    private void Form1_Load(System.Object sender, System.EventArgs e)
    {
        try
        {
            SetUpForm();
            SetUpDataGridView1();
            SetUpDataGridView2();
        }
        catch (SqlException)
        {
            MessageBox.Show("The connection string <"
                + connectionString
                + "> failed to connect.  Modify it "
                + "to connect to a Northwind database accessible to "
                + "your system.",
                "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            Application.Exit();
        }
    }

    private void SetUpForm()
    {
        Size = new Size(800, 600);
        FlowLayoutPanel flowLayout = new FlowLayoutPanel();
        flowLayout.FlowDirection = FlowDirection.TopDown;
        flowLayout.Dock = DockStyle.Fill;
        Controls.Add(flowLayout);
        Text = "DataGridView columns demo";

        flowLayout.Controls.Add(DataGridView1);
        flowLayout.Controls.Add(DataGridView2);
    }

    private void SetUpDataGridView2()
    {
        DataGridView2.Dock = DockStyle.Bottom;
        DataGridView2.TopLeftHeaderCell.Value = "Sales Details";
        DataGridView2.RowHeadersWidthSizeMode = 
            DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders;
    }

    private void SetUpDataGridView1()
    {
        DataGridView1.DataError += new 
            DataGridViewDataErrorEventHandler(DataGridView1_DataError);
        DataGridView1.CellContentClick += new 
            DataGridViewCellEventHandler(DataGridView1_CellContentClick);
        DataGridView1.CellValuePushed += new 
            DataGridViewCellValueEventHandler(DataGridView1_CellValuePushed);
        DataGridView1.CellValueNeeded += new 
            DataGridViewCellValueEventHandler(DataGridView1_CellValueNeeded);

        // Virtual mode is turned on so that the
        // unbound DataGridViewCheckBoxColumn will
        // keep its state when the bound columns are
        // sorted.       
        DataGridView1.VirtualMode = true;
        DataGridView1.AutoSize = true;
        DataGridView1.DataSource = Populate("SELECT * FROM Employees");
        DataGridView1.TopLeftHeaderCell.Value = "Employees";
        DataGridView1.RowHeadersWidthSizeMode = 
            DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders;
        DataGridView1.ColumnHeadersHeightSizeMode = 
            DataGridViewColumnHeadersHeightSizeMode.AutoSize;
        DataGridView1.AutoSizeColumnsMode = 
            DataGridViewAutoSizeColumnsMode.AllCells;
        DataGridView1.AllowUserToAddRows = false;
        DataGridView1.AllowUserToDeleteRows = false;

        // The below autogenerated column is removed so 
        // a DataGridViewComboboxColumn could be used instead.
        DataGridView1.Columns.Remove(ColumnName.TitleOfCourtesy.ToString());
        DataGridView1.Columns.Remove(ColumnName.ReportsTo.ToString());

        AddLinkColumn();
        AddComboBoxColumns();
        AddButtonColumn();
        AddOutOfOfficeColumn();
    }

    private void AddComboBoxColumns()
    {
        DataGridViewComboBoxColumn comboboxColumn;
        comboboxColumn = CreateComboBoxColumn();
        SetAlternateChoicesUsingDataSource(comboboxColumn);
        comboboxColumn.HeaderText = "TitleOfCourtesy (via DataSource property)";
        DataGridView1.Columns.Insert(0, comboboxColumn);

        comboboxColumn = CreateComboBoxColumn();
        SetAlternateChoicesUsingItems(comboboxColumn);
        comboboxColumn.HeaderText = "TitleOfCourtesy (via Items property)";
        // Tack this example column onto the end.
        DataGridView1.Columns.Add(comboboxColumn);
    }

    private void AddLinkColumn()
    {
        DataGridViewLinkColumn links = new DataGridViewLinkColumn();

        links.UseColumnTextForLinkValue = true;
        links.HeaderText = ColumnName.ReportsTo.ToString();
        links.DataPropertyName = ColumnName.ReportsTo.ToString();
        links.ActiveLinkColor = Color.White;
        links.LinkBehavior = LinkBehavior.SystemDefault;
        links.LinkColor = Color.Blue;
        links.TrackVisitedState = true;
        links.VisitedLinkColor = Color.YellowGreen;

        DataGridView1.Columns.Add(links);
    }

    private static void SetAlternateChoicesUsingItems(
        DataGridViewComboBoxColumn comboboxColumn)
    {
        comboboxColumn.Items.AddRange("Mr.", "Ms.", "Mrs.", "Dr.");
    }

    private DataGridViewComboBoxColumn CreateComboBoxColumn()
    {
        DataGridViewComboBoxColumn column =
            new DataGridViewComboBoxColumn();
        {
            column.DataPropertyName = ColumnName.TitleOfCourtesy.ToString();
            column.HeaderText = ColumnName.TitleOfCourtesy.ToString();
            column.DropDownWidth = 160;
            column.Width = 90;
            column.MaxDropDownItems = 3;
            column.FlatStyle = FlatStyle.Flat;
        }
        return column;
    }

    private void SetAlternateChoicesUsingDataSource(DataGridViewComboBoxColumn comboboxColumn)
    {
        {
            comboboxColumn.DataSource = RetrieveAlternativeTitles();
            comboboxColumn.ValueMember = ColumnName.TitleOfCourtesy.ToString();
            comboboxColumn.DisplayMember = comboboxColumn.ValueMember;
        }
    }

    private DataTable RetrieveAlternativeTitles()
    {
        return Populate("SELECT distinct TitleOfCourtesy FROM Employees");
    }

    string connectionString =
        "Integrated Security=SSPI;Persist Security Info=False;" +
        "Initial Catalog=Northwind;Data Source=localhost";

    private DataTable Populate(string sqlCommand)
    {
        SqlConnection northwindConnection = new SqlConnection(connectionString);
        northwindConnection.Open();

        SqlCommand command = new SqlCommand(sqlCommand, northwindConnection);
        SqlDataAdapter adapter = new SqlDataAdapter();
        adapter.SelectCommand = command;

        DataTable table = new DataTable();
        table.Locale = System.Globalization.CultureInfo.InvariantCulture;
        adapter.Fill(table);

        return table;
    }

    // Using an enum provides some abstraction between column index
    // and column name along with compile time checking, and gives
    // a handy place to store the column names.
    enum ColumnName
    {
        EmployeeId,
        LastName,
        FirstName,
        Title,
        TitleOfCourtesy,
        BirthDate,
        HireDate,
        Address,
        City,
        Region,
        PostalCode,
        Country,
        HomePhone,
        Extension,
        Photo,
        Notes,
        ReportsTo,
        PhotoPath,
        OutOfOffice
    };

    private void AddButtonColumn()
    {
        DataGridViewButtonColumn buttons = new DataGridViewButtonColumn();
        {
            buttons.HeaderText = "Sales";
            buttons.Text = "Sales";
            buttons.UseColumnTextForButtonValue = true;
            buttons.AutoSizeMode =
                DataGridViewAutoSizeColumnMode.AllCells;
            buttons.FlatStyle = FlatStyle.Standard;
            buttons.CellTemplate.Style.BackColor = Color.Honeydew;
            buttons.DisplayIndex = 0;
        }

        DataGridView1.Columns.Add(buttons);
    }

    private void AddOutOfOfficeColumn()
    {
        DataGridViewCheckBoxColumn column = new DataGridViewCheckBoxColumn();
        {
            column.HeaderText = ColumnName.OutOfOffice.ToString();
            column.Name = ColumnName.OutOfOffice.ToString();
            column.AutoSizeMode = 
                DataGridViewAutoSizeColumnMode.DisplayedCells;
            column.FlatStyle = FlatStyle.Standard;
            column.ThreeState = true;
            column.CellTemplate = new DataGridViewCheckBoxCell();
            column.CellTemplate.Style.BackColor = Color.Beige;
        }

        DataGridView1.Columns.Insert(0, column);
    }

    private void PopulateSales(DataGridViewCellEventArgs buttonClick)
    {

        string employeeId = DataGridView1.Rows[buttonClick.RowIndex]
            .Cells[ColumnName.EmployeeId.ToString()].Value.ToString();
        DataGridView2.DataSource = Populate("SELECT * FROM Orders WHERE EmployeeId = " + employeeId);
    }

    #region "SQL Error handling"
    private void DataGridView1_DataError(object sender, DataGridViewDataErrorEventArgs anError)
    {

        MessageBox.Show("Error happened " + anError.Context.ToString());

        if (anError.Context == DataGridViewDataErrorContexts.Commit)
        {
            MessageBox.Show("Commit error");
        }
        if (anError.Context == DataGridViewDataErrorContexts.CurrentCellChange)
        {
            MessageBox.Show("Cell change");
        }
        if (anError.Context == DataGridViewDataErrorContexts.Parsing)
        {
            MessageBox.Show("parsing error");
        }
        if (anError.Context == DataGridViewDataErrorContexts.LeaveControl)
        {
            MessageBox.Show("leave control error");
        }

        if ((anError.Exception) is ConstraintException)
        {
            DataGridView view = (DataGridView)sender;
            view.Rows[anError.RowIndex].ErrorText = "an error";
            view.Rows[anError.RowIndex].Cells[anError.ColumnIndex].ErrorText = "an error";

            anError.ThrowException = false;
        }
    }
    #endregion

    private void DataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
    {

        if (IsANonHeaderLinkCell(e))
        {
            MoveToLinked(e);
        }
        else if (IsANonHeaderButtonCell(e))
        {
            PopulateSales(e);
        }
    }

    private void MoveToLinked(DataGridViewCellEventArgs e)
    {
        string employeeId;
        object value = DataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
        if (value is DBNull) { return; }

        employeeId = value.ToString();
        DataGridViewCell boss = RetrieveSuperiorsLastNameCell(employeeId);
        if (boss != null)
        {
            DataGridView1.CurrentCell = boss;
        }
    }

    private bool IsANonHeaderLinkCell(DataGridViewCellEventArgs cellEvent)
    {
        if (DataGridView1.Columns[cellEvent.ColumnIndex] is
            DataGridViewLinkColumn &&
            cellEvent.RowIndex != -1)
        { return true; }
        else { return false; }
    }

    private bool IsANonHeaderButtonCell(DataGridViewCellEventArgs cellEvent)
    {
        if (DataGridView1.Columns[cellEvent.ColumnIndex] is
            DataGridViewButtonColumn &&
            cellEvent.RowIndex != -1)
        { return true; }
        else { return (false); }
    }

    private DataGridViewCell RetrieveSuperiorsLastNameCell(string employeeId)
    {

        foreach (DataGridViewRow row in DataGridView1.Rows)
        {
            if (row.IsNewRow) { return null; }
            if (row.Cells[ColumnName.EmployeeId.ToString()].Value.ToString().Equals(employeeId))
            {
                return row.Cells[ColumnName.LastName.ToString()];
            }
        }
        return null;
    }

    #region "checkbox state"
    Dictionary<string, bool> inOffice = new Dictionary<string, bool>();
    private void DataGridView1_CellValuePushed(object sender,
        DataGridViewCellValueEventArgs e)
    {
        if (IsCheckBoxColumn(e.ColumnIndex))
        {
            string employeeId = GetKey(e);
            if (!inOffice.ContainsKey(employeeId))
            {
                inOffice.Add(employeeId, (Boolean)e.Value);
            }
            else
            {
                inOffice[employeeId] = (Boolean)e.Value;
            }
        }
    }

    private string GetKey(DataGridViewCellValueEventArgs cell)
    {
        return DataGridView1.Rows[cell.RowIndex].
            Cells[ColumnName.EmployeeId.ToString()].Value.ToString();
    }

    private void DataGridView1_CellValueNeeded(object sender,
        DataGridViewCellValueEventArgs e)
    {

        if (IsCheckBoxColumn(e.ColumnIndex))
        {
            string employeeId = GetKey(e);
            if (!inOffice.ContainsKey(employeeId))
            {
                bool defaultValue = false;
                inOffice.Add(employeeId, defaultValue);
            }

            e.Value = inOffice[employeeId];
        }
    }

    private bool IsCheckBoxColumn(int columnIndex)
    {
        DataGridViewColumn outOfOfficeColumn =
            DataGridView1.Columns[ColumnName.OutOfOffice.ToString()];
        return (DataGridView1.Columns[columnIndex] == outOfOfficeColumn);
    }
    #endregion
}

Imports System.Data
Imports System.Data.SqlClient
Imports System.Windows.Forms
Imports System.Collections.Generic
Imports System.Drawing

Public Class Employees
    Inherits System.Windows.Forms.Form

    Private WithEvents DataGridView1 As New DataGridView
    Private WithEvents DataGridView2 As New DataGridView

    <STAThreadAttribute()> _
    Public Shared Sub Main()
        Try
            Application.EnableVisualStyles()
            Application.Run(New Employees())
        Catch e As Exception
            MessageBox.Show(e.Message & e.StackTrace)
        End Try
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load

        Try
            SetUpForm()
            SetUpDataGridView1()
            SetUpDataGridView2()
        Catch ex As SqlException
            MessageBox.Show("The connection string <" _
                & connectionString _
                & "> failed to connect.  Modify it to connect to " _
                & "a Northwind database accessible to your system.", _
                "ERROR", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
            Application.Exit()
        End Try
    End Sub

    Private Sub SetUpForm()
        Size = New Size(800, 600)
        Dim flowLayout As New FlowLayoutPanel()
        flowLayout.FlowDirection = FlowDirection.TopDown
        flowLayout.Dock = DockStyle.Fill
        Controls.Add(flowLayout)
        Text = "DataGridView columns demo"

        flowLayout.Controls.Add(DataGridView1)
        flowLayout.Controls.Add(DataGridView2)
    End Sub

    Private Sub SetUpDataGridView2()
        DataGridView2.Dock = DockStyle.Bottom
        DataGridView2.TopLeftHeaderCell.Value = "Sales Details"
        DataGridView2.RowHeadersWidthSizeMode = _
        DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders
    End Sub

    Private Sub SetUpDataGridView1()
        ' Virtual mode is turned on so that the
        ' unbound DataGridViewCheckBoxColumn will
        ' keep its state when the bound columns are
        ' sorted.
        DataGridView1.VirtualMode = True

        DataGridView1.AutoSize = True
        DataGridView1.DataSource = _
            Populate("SELECT * FROM Employees")
        DataGridView1.TopLeftHeaderCell.Value = "Employees"
        DataGridView1.RowHeadersWidthSizeMode = _
            DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders
        DataGridView1.ColumnHeadersHeightSizeMode = _
            DataGridViewColumnHeadersHeightSizeMode.AutoSize
        DataGridView1.AutoSizeColumnsMode = _
            DataGridViewAutoSizeColumnsMode.AllCells
        DataGridView1.AllowUserToAddRows = False
        DataGridView1.AllowUserToDeleteRows = False

        ' The below autogenerated column is removed so 
        ' a DataGridViewComboboxColumn could be used instead.
        DataGridView1.Columns.Remove( _
            ColumnName.TitleOfCourtesy.ToString())
        DataGridView1.Columns.Remove(ColumnName.ReportsTo.ToString())

        AddLinkColumn()
        AddComboBoxColumns()
        AddButtonColumn()
        AddOutOfOfficeColumn()
    End Sub

    Private Sub AddComboBoxColumns()
        Dim comboboxColumn As DataGridViewComboBoxColumn
        comboboxColumn = CreateComboBoxColumn()
        SetAlternateChoicesUsingDataSource(comboboxColumn)
        comboboxColumn.HeaderText = _
            "TitleOfCourtesy (via DataSource property)"
        DataGridView1.Columns.Insert(0, comboboxColumn)

        comboboxColumn = CreateComboBoxColumn()
        SetAlternateChoicesUsingItems(comboboxColumn)
        comboboxColumn.HeaderText = _
            "TitleOfCourtesy (via Items property)"
        ' Tack this example column onto the end.
        DataGridView1.Columns.Add(comboboxColumn)
    End Sub

    Private Sub AddLinkColumn()

        Dim links As New DataGridViewLinkColumn()
        With links
            .UseColumnTextForLinkValue = True
            .HeaderText = ColumnName.ReportsTo.ToString()
            .DataPropertyName = ColumnName.ReportsTo.ToString()
            .ActiveLinkColor = Color.White
            .LinkBehavior = LinkBehavior.SystemDefault
            .LinkColor = Color.Blue
            .TrackVisitedState = True
            .VisitedLinkColor = Color.YellowGreen
        End With
        DataGridView1.Columns.Add(links)
    End Sub

    Private Shared Sub SetAlternateChoicesUsingItems( _
        ByVal comboboxColumn As DataGridViewComboBoxColumn)

        comboboxColumn.Items.AddRange("Mr.", "Ms.", "Mrs.", "Dr.")

    End Sub

    Private Function CreateComboBoxColumn() _
        As DataGridViewComboBoxColumn
        Dim column As New DataGridViewComboBoxColumn()

        With column
            .DataPropertyName = ColumnName.TitleOfCourtesy.ToString()
            .HeaderText = ColumnName.TitleOfCourtesy.ToString()
            .DropDownWidth = 160
            .Width = 90
            .MaxDropDownItems = 3
            .FlatStyle = FlatStyle.Flat
        End With
        Return column
    End Function

    Private Sub SetAlternateChoicesUsingDataSource( _
        ByVal comboboxColumn As DataGridViewComboBoxColumn)
        With comboboxColumn
            .DataSource = RetrieveAlternativeTitles()
            .ValueMember = ColumnName.TitleOfCourtesy.ToString()
            .DisplayMember = .ValueMember
        End With
    End Sub

    Private Function RetrieveAlternativeTitles() As DataTable
        Return Populate( _
            "SELECT distinct TitleOfCourtesy FROM Employees")
    End Function

    Private connectionString As String = _
            "Integrated Security=SSPI;Persist Security Info=False;" _
            & "Initial Catalog=Northwind;Data Source=localhost"

    Private Function Populate(ByVal sqlCommand As String) As DataTable
        Dim northwindConnection As New SqlConnection(connectionString)
        northwindConnection.Open()

        Dim command As New SqlCommand(sqlCommand, _
            northwindConnection)
        Dim adapter As New SqlDataAdapter()
        adapter.SelectCommand = command
        Dim table As New DataTable()
        table.Locale = System.Globalization.CultureInfo.InvariantCulture
        adapter.Fill(table)

        Return table
    End Function

    ' Using an enum provides some abstraction between column index
    ' and column name along with compile time checking, and gives
    ' a handy place to store the column names.
    Enum ColumnName
        EmployeeId
        LastName
        FirstName
        Title
        TitleOfCourtesy
        BirthDate
        HireDate
        Address
        City
        Region
        PostalCode
        Country
        HomePhone
        Extension
        Photo
        Notes
        ReportsTo
        PhotoPath
        OutOfOffice
    End Enum

    Private Sub AddButtonColumn()
        Dim buttons As New DataGridViewButtonColumn()
        With buttons
            .HeaderText = "Sales"
            .Text = "Sales"
            .UseColumnTextForButtonValue = True
            .AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
            .FlatStyle = FlatStyle.Standard
            .CellTemplate.Style.BackColor = Color.Honeydew
            .DisplayIndex = 0
        End With

        DataGridView1.Columns.Add(buttons)

    End Sub

    Private Sub AddOutOfOfficeColumn()
        Dim column As New DataGridViewCheckBoxColumn()
        With column
            .HeaderText = ColumnName.OutOfOffice.ToString()
            .Name = ColumnName.OutOfOffice.ToString()
            .AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells
            .FlatStyle = FlatStyle.Standard
            .CellTemplate = New DataGridViewCheckBoxCell()
            .CellTemplate.Style.BackColor = Color.Beige
        End With

        DataGridView1.Columns.Insert(0, column)
    End Sub

    Private Sub PopulateSales( _
        ByVal buttonClick As DataGridViewCellEventArgs)

        Dim employeeId As String = _
            DataGridView1.Rows(buttonClick.RowIndex). _
            Cells(ColumnName.EmployeeId.ToString()).Value().ToString()
        DataGridView2.DataSource = Populate( _
            "SELECT * FROM Orders WHERE EmployeeId = " & employeeId)
    End Sub

#Region "SQL Error handling"
    Private Sub DataGridView1_DataError(ByVal sender As Object, _
    ByVal e As DataGridViewDataErrorEventArgs) _
    Handles DataGridView1.DataError

        MessageBox.Show("Error happened " _
            & e.Context.ToString())

        If (e.Context = DataGridViewDataErrorContexts.Commit) _
            Then
            MessageBox.Show("Commit error")
        End If
        If (e.Context = DataGridViewDataErrorContexts _
            .CurrentCellChange) Then
            MessageBox.Show("Cell change")
        End If
        If (e.Context = DataGridViewDataErrorContexts.Parsing) _
            Then
            MessageBox.Show("parsing error")
        End If
        If (e.Context = _
            DataGridViewDataErrorContexts.LeaveControl) Then
            MessageBox.Show("leave control error")
        End If

        If (TypeOf (e.Exception) Is ConstraintException) Then
            Dim view As DataGridView = CType(sender, DataGridView)
            view.Rows(e.RowIndex).ErrorText = "an error"
            view.Rows(e.RowIndex).Cells(e.ColumnIndex) _
                .ErrorText = "an error"

            e.ThrowException = False
        End If
    End Sub
#End Region

    Private Sub DataGridView1_CellContentClick(ByVal sender As Object, _
        ByVal e As DataGridViewCellEventArgs) _
        Handles DataGridView1.CellContentClick

        If IsANonHeaderLinkCell(e) Then
            MoveToLinked(e)
        ElseIf IsANonHeaderButtonCell(e) Then
            PopulateSales(e)
        End If
    End Sub

    Private Sub MoveToLinked(ByVal e As DataGridViewCellEventArgs)
        Dim employeeId As String
        Dim value As Object = DataGridView1.Rows(e.RowIndex). _
            Cells(e.ColumnIndex).Value
        If value.GetType Is GetType(DBNull) Then Return

        employeeId = CType(value, String)
        Dim boss As DataGridViewCell = _
            RetrieveSuperiorsLastNameCell(employeeId)
        If boss IsNot Nothing Then
            DataGridView1.CurrentCell = boss
        End If
    End Sub

    Private Function IsANonHeaderLinkCell(ByVal cellEvent As _
        DataGridViewCellEventArgs) As Boolean

        If TypeOf DataGridView1.Columns(cellEvent.ColumnIndex) _
            Is DataGridViewLinkColumn _
            AndAlso Not cellEvent.RowIndex = -1 Then _
            Return True Else Return False

    End Function

    Private Function IsANonHeaderButtonCell(ByVal cellEvent As _
        DataGridViewCellEventArgs) As Boolean

        If TypeOf DataGridView1.Columns(cellEvent.ColumnIndex) _
            Is DataGridViewButtonColumn _
            AndAlso Not cellEvent.RowIndex = -1 Then _
            Return True Else Return (False)

    End Function

    Private Function RetrieveSuperiorsLastNameCell( _
        ByVal employeeId As String) As DataGridViewCell

        For Each row As DataGridViewRow In DataGridView1.Rows
            If row.IsNewRow Then Return Nothing
            If row.Cells(ColumnName.EmployeeId.ToString()). _
                Value.ToString().Equals(employeeId) Then
                Return row.Cells(ColumnName.LastName.ToString())
            End If
        Next
        Return Nothing
    End Function

#Region "checkbox state"
    Dim inOffice As New Dictionary(Of String, Boolean)
    Private Sub DataGridView1_CellValuePushed(ByVal sender As Object, _
     ByVal e As DataGridViewCellValueEventArgs) _
        Handles DataGridView1.CellValuePushed

        If IsCheckBoxColumn(e.ColumnIndex) Then
            Dim employeeId As String = GetKey(e)
            If Not inOffice.ContainsKey(employeeId) Then
                inOffice.Add(employeeId, CType(e.Value, Boolean))
            Else
                inOffice.Item(employeeId) = CType(e.Value, Boolean)
            End If
        End If
    End Sub

    Private Function GetKey(ByVal cell As DataGridViewCellValueEventArgs) As String
        Return DataGridView1.Rows(cell.RowIndex).Cells( _
            ColumnName.EmployeeId.ToString()).Value().ToString()
    End Function

    Private Sub DataGridView1_CellValueNeeded(ByVal sender As Object, _
     ByVal e As DataGridViewCellValueEventArgs) _
        Handles DataGridView1.CellValueNeeded

        If IsCheckBoxColumn(e.ColumnIndex) Then
            Dim employeeId As String = GetKey(e)
            If Not inOffice.ContainsKey(employeeId) Then
                Dim defaultValue As Boolean = False
                inOffice.Add(employeeId, defaultValue)
            End If

            e.Value = inOffice.Item(employeeId)
        End If
    End Sub

    Private Function IsCheckBoxColumn(ByVal columnIndex As Integer) As Boolean

        Dim outOfOfficeColumn As DataGridViewColumn = _
            DataGridView1.Columns(ColumnName.OutOfOffice.ToString())
        Return (DataGridView1.Columns(columnIndex) Is outOfOfficeColumn)

    End Function
#End Region

End Class

Comentarios

La DataGridViewComboBoxColumn clase es un tipo especializado de DataGridViewColumn que se usa para hospedar lógicamente las celdas que permiten a los usuarios seleccionar valores de una lista de opciones. DataGridViewComboBoxColumn un objeto tiene asociado DataGridViewComboBoxCell en cada DataGridViewRow que lo intersecta.

Puede rellenar las celdas manualmente estableciendo sus Value propiedades. Como alternativa, puede enlazar la columna al origen de datos indicado por la DataGridView.DataSource propiedad . DataGridView Si está enlazado a una tabla de base de datos, establezca la propiedad column DataPropertyName en el nombre de una columna de la tabla. DataGridView Si está enlazado a una colección de objetos, establezca la DataPropertyName propiedad en el nombre de una propiedad de objeto.

Puede rellenar la lista desplegable de columnas manualmente agregando valores a la Items colección. Como alternativa, puede enlazar la lista desplegable a su propio origen de datos estableciendo la propiedad column DataSource . Si los valores son objetos de una colección o registros de una tabla de base de datos, también debe establecer las DisplayMember propiedades y ValueMember . La DisplayMember propiedad indica qué propiedad de objeto o columna de base de datos proporciona los valores que se muestran en la lista desplegable. La ValueMember propiedad indica qué propiedad de objeto o columna de base de datos se usa para establecer la propiedad cell Value .

Un escenario típico es enlazar el DataGridView control a una tabla de base de datos primaria y enlazar la lista desplegable a una tabla secundaria relacionada. Por ejemplo, puede enlazar el DataGridView control a una Orders tabla que contiene una ProductID columna y establecer la propiedad column DataSource en una Products tabla que contiene ProductID columnas y ProductName . En este caso, establecería la propiedad column DataPropertyName en "ProductID" para rellenar sus valores de celda de la Orders.ProductID columna. Sin embargo, para mostrar los nombres de producto reales en las celdas y la lista desplegable, debe asignar estos valores a la Products tabla estableciendo la ValueMember propiedad en "ProductID" y la DisplayMember propiedad en "ProductName".

Los valores de lista desplegable (o los valores indicados por la ValueMember propiedad) deben incluir los valores de celda reales o el DataGridView control producirá una excepción.

Al establecer las propiedades de columna DataSource, DisplayMembery ValueMember , se establecen automáticamente las propiedades correspondientes de todas las celdas de la columna, incluido .CellTemplate Para invalidar estos valores de propiedad para celdas específicas, establezca primero la propiedad column y, a continuación, establezca las propiedades de celda.

A diferencia del ComboBox control , no DataGridViewComboBoxCell tiene SelectedIndex propiedades y SelectedValue . En su lugar, al seleccionar un valor en una lista desplegable, se establece la propiedad cell Value .

El modo de ordenación predeterminado para este tipo de columna es NotSortable.

Notas a los desarrolladores de herederos

Cuando derive de DataGridViewComboBoxColumn y agregue nuevas propiedades a la clase derivada, asegúrese de invalidar el Clone() método para copiar las nuevas propiedades durante las operaciones de clonación. También debe llamar al método de Clone() la clase base para que las propiedades de la clase base se copien en la nueva celda.

Constructores

Propiedades

Métodos

Eventos

Se aplica a

Consulte también

• DataGridView
• DataSource
• DataPropertyName
• DataSource
• Items
• ValueMember
• DisplayMember
• DataGridViewColumn
• DataGridViewRow
• DataGridViewComboBoxCell
• DataGridViewComboBoxEditingControl
• SortMode
• Procedimiento para obtener acceso a objetos de una lista desplegable DataGridViewComboBoxCell en formularios Windows Forms