Gewusst wie: Freigeben von gebundenen Daten in Formularen mithilfe der BindingSource-Komponente
Aktualisiert: November 2007
Sie können Daten mit der BindingSource-Komponente auf einfache Weise in Formularen freigeben. Dies kann beispielsweise der Fall sein, wenn Sie ein schreibgeschütztes Formular, in dem die Daten der Datenquellen zusammengefasst werden, und ein weiteres, bearbeitbares Formular anzeigen möchten, das ausführliche Informationen über das gegenwärtig in der Datenquelle ausgewählte Element enthält. In diesem Beispiel wird dieses Szenario veranschaulicht.
Beispiel
Im folgenden Codebeispiel wird erläutert, wie BindingSource und daran gebundene Daten in Formularen freigegeben werden. In diesem Beispiel wird die freigegebene BindingSource an den Konstruktor des untergeordneten Formulars übergeben. Das untergeordnete Formular ermöglicht dem Benutzer, die Daten des derzeit ausgewählten Elements im Hauptformular zu bearbeiten.
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Das BindingComplete-Ereignis für die BindingSource-Komponente wird in dem Beispiel behandelt, um sicherzustellen, dass die beiden Formulare synchronisiert bleiben. Weitere Informationen dazu finden Sie unter Gewusst wie: Sicherstellen, dass mehrere Steuerelemente, die an die gleiche Datenquelle gebunden sind, synchronisiert bleiben. |
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Data
Public Class MainForm
Inherits Form
Public Sub New()
End Sub
Private WithEvents bindingSource1 As BindingSource
Private WithEvents button1 As Button
Private Sub MainForm_Load(ByVal sender As Object, ByVal e As EventArgs) _
Handles Me.Load
InitializeData()
End Sub
Private Sub InitializeData()
bindingSource1 = New System.Windows.Forms.BindingSource()
Dim dataset1 As New DataSet()
ClientSize = New System.Drawing.Size(292, 266)
' Some xml data to populate the DataSet with.
' Some xml data to populate the DataSet with.
Dim musicXml As String = "<?xml version='1.0' encoding='UTF-8'?>" & _
"<music><recording><artist>Dave Matthews</artist>" & _
"<cd>Under the Table and Dreaming</cd>" & _
"<releaseDate>1994</releaseDate><rating>3.5</rating></recording>" & _
"<recording><artist>Coldplay</artist><cd>X&Y</cd>" & _
"<releaseDate>2005</releaseDate><rating>4</rating></recording>" & _
"<recording><artist>Dave Matthews</artist>" & _
"<cd>Live at Red Rocks</cd>" & _
"<releaseDate>1997</releaseDate><rating>4</rating></recording>" & _
"<recording><artist>U2</artist>" & _
"<cd>Joshua Tree</cd><releaseDate>1987</releaseDate>" & _
"<rating>5</rating></recording>" & _
"<recording><artist>U2</artist>" & _
"<cd>How to Dismantle an Atomic Bomb</cd>" & _
"<releaseDate>2004</releaseDate><rating>4.5</rating></recording>" & _
"<recording><artist>Natalie Merchant</artist>" & _
"<cd>Tigerlily</cd><releaseDate>1995</releaseDate>" & _
"<rating>3.5</rating></recording>" & _
"</music>"
' Read the xml.
Dim reader As New System.IO.StringReader(musicXml)
dataset1.ReadXml(reader)
' Get a DataView of the table contained in the dataset.
Dim tables As DataTableCollection = dataset1.Tables
Dim view1 As New DataView(tables(0))
' Create a DataGridView control and add it to the form.
Dim datagridview1 As New DataGridView()
datagridview1.ReadOnly = True
datagridview1.AutoGenerateColumns = True
datagridview1.Width = 300
Me.Controls.Add(datagridview1)
bindingSource1.DataSource = view1
datagridview1.DataSource = bindingSource1
datagridview1.Columns.Remove("artist")
datagridview1.Columns.Remove("releaseDate")
' Create and add a button to the form.
button1 = New Button()
button1.AutoSize = True
button1.Text = "Show/Edit Details"
Me.Controls.Add(button1)
button1.Location = New Point(50, 200)
End Sub
' Handle the BindingComplete event to ensure the two forms
' remain synchronized.
Private Sub bindingSource1_BindingComplete(ByVal sender As Object, _
ByVal e As BindingCompleteEventArgs) Handles bindingSource1.BindingComplete
If e.BindingCompleteContext = BindingCompleteContext.DataSourceUpdate _
AndAlso e.Exception Is Nothing Then
e.Binding.BindingManagerBase.EndCurrentEdit()
End If
End Sub
' The detailed form will be shown when the button is clicked.
Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
Handles button1.Click
Dim detailForm As New DetailForm(bindingSource1)
detailForm.Show()
End Sub
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New MainForm())
End Sub
End Class
' The detail form class.
Public Class DetailForm
Inherits Form
Private formDataSource As BindingSource
' The constructor takes a BindingSource object.
Public Sub New(ByVal dataSource As BindingSource)
formDataSource = dataSource
Me.ClientSize = New Size(240, 200)
Dim textBox1 As New TextBox()
Me.Text = "Selection Details"
textBox1.Width = 220
Dim textBox2 As New TextBox()
Dim textBox3 As New TextBox()
Dim textBox4 As New TextBox()
textBox4.Width = 30
textBox3.Width = 50
' Associate each text box with a column from the data source.
textBox1.DataBindings.Add("Text", formDataSource, "cd", _
True, DataSourceUpdateMode.OnPropertyChanged)
textBox2.DataBindings.Add("Text", formDataSource, "artist", True)
textBox3.DataBindings.Add("Text", formDataSource, "releaseDate", True)
textBox4.DataBindings.Add("Text", formDataSource, "rating", True)
textBox1.Location = New Point(10, 10)
textBox2.Location = New Point(10, 40)
textBox3.Location = New Point(10, 80)
textBox4.Location = New Point(10, 120)
Me.Controls.AddRange(New Control() {textBox1, textBox2, textBox3, _
textBox4})
End Sub
End Class
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Data;
namespace BindingSourceMultipleForms
{
public class MainForm : Form
{
public MainForm()
{
this.Load += new EventHandler(MainForm_Load);
}
private BindingSource bindingSource1;
private Button button1;
private void MainForm_Load(object sender, EventArgs e)
{
InitializeData();
}
private void InitializeData()
{
bindingSource1 = new System.Windows.Forms.BindingSource();
// Handle the BindingComplete event to ensure the two forms
// remain synchronized.
bindingSource1.BindingComplete +=
new BindingCompleteEventHandler(bindingSource1_BindingComplete);
ClientSize = new System.Drawing.Size(292, 266);
DataSet dataset1 = new DataSet();
// Some xml data to populate the DataSet with.
string musicXml =
"<?xml version='1.0' encoding='UTF-8'?>" +
"<music>" +
"<recording><artist>Dave Matthews</artist>" +
"<cd>Under the Table and Dreaming</cd>" +
"<releaseDate>1994</releaseDate><rating>3.5</rating></recording>" +
"<recording><artist>Coldplay</artist><cd>X&Y</cd>" +
"<releaseDate>2005</releaseDate><rating>4</rating></recording>" +
"<recording><artist>Dave Matthews</artist>" +
"<cd>Live at Red Rocks</cd>" +
"<releaseDate>1997</releaseDate><rating>4</rating></recording>" +
"<recording><artist>U2</artist>" +
"<cd>Joshua Tree</cd><releaseDate>1987</releaseDate>" +
"<rating>5</rating></recording>" +
"<recording><artist>U2</artist>" +
"<cd>How to Dismantle an Atomic Bomb</cd>" +
"<releaseDate>2004</releaseDate><rating>4.5</rating></recording>" +
"<recording><artist>Natalie Merchant</artist>" +
"<cd>Tigerlily</cd><releaseDate>1995</releaseDate>" +
"<rating>3.5</rating></recording>" +
"</music>";
// Read the xml.
System.IO.StringReader reader = new System.IO.StringReader(musicXml);
dataset1.ReadXml(reader);
// Get a DataView of the table contained in the dataset.
DataTableCollection tables = dataset1.Tables;
DataView view1 = new DataView(tables[0]);
// Create a DataGridView control and add it to the form.
DataGridView datagridview1 = new DataGridView();
datagridview1.ReadOnly = true;
datagridview1.AutoGenerateColumns = true;
datagridview1.Width = 300;
this.Controls.Add(datagridview1);
bindingSource1.DataSource = view1;
datagridview1.DataSource = bindingSource1;
datagridview1.Columns.Remove("artist");
datagridview1.Columns.Remove("releaseDate");
// Create and add a button to the form.
button1 = new Button();
button1.AutoSize = true;
button1.Text = "Show/Edit Details";
this.Controls.Add(button1);
button1.Location = new Point(50, 200);
button1.Click += new EventHandler(button1_Click);
}
// Handle the BindingComplete event to ensure the two forms
// remain synchronized.
private void bindingSource1_BindingComplete(object sender, BindingCompleteEventArgs e)
{
if (e.BindingCompleteContext == BindingCompleteContext.DataSourceUpdate
&& e.Exception == null)
e.Binding.BindingManagerBase.EndCurrentEdit();
}
// The detailed form will be shown when the button is clicked.
private void button1_Click(object sender, EventArgs e)
{
DetailForm detailForm = new DetailForm(bindingSource1);
detailForm.Show();
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new MainForm());
}
}
// The detail form class.
public class DetailForm : Form
{
private BindingSource formDataSource;
// The constructor takes a BindingSource object.
public DetailForm(BindingSource dataSource)
{
formDataSource = dataSource;
this.ClientSize = new Size(240, 200);
TextBox textBox1 = new TextBox();
this.Text = "Selection Details";
textBox1.Width = 220;
TextBox textBox2 = new TextBox();
TextBox textBox3 = new TextBox();
TextBox textBox4 = new TextBox();
textBox4.Width = 30;
textBox3.Width = 50;
// Associate each text box with a column from the data source.
textBox1.DataBindings.Add("Text", formDataSource, "cd", true, DataSourceUpdateMode.OnPropertyChanged);
textBox2.DataBindings.Add("Text", formDataSource, "artist", true);
textBox3.DataBindings.Add("Text", formDataSource, "releaseDate", true);
textBox4.DataBindings.Add("Text", formDataSource, "rating", true);
textBox1.Location = new Point(10, 10);
textBox2.Location = new Point(10, 40);
textBox3.Location = new Point(10, 80);
textBox4.Location = new Point(10, 120);
this.Controls.AddRange(new Control[] { textBox1, textBox2, textBox3, textBox4 });
}
}
}
Kompilieren des Codes
Für dieses Beispiel sind erforderlich:
- Verweise auf die Assemblys System, System.Windows.Forms, System.Drawing, System.Data und System.Xml.
Informationen zum Erstellen dieses Beispiels über die Befehlszeile für Visual Basic oder Visual C# finden Sie unter Erstellen von der Befehlszeile aus (Visual Basic) und Erstellen über die Befehlszeile mit csc.exe. Sie können dieses Beispiel auch in Visual Studio erstellen, indem Sie den Code in ein neues Projekt einfügen.
Siehe auch
Aufgaben
Gewusst wie: Behandeln von Fehlern und Ausnahmen in Zusammenhang mit der Datenbindung