GridView.RowCommand Evento

Referência

Definição

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Importante

Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.

Ocorre quando se clica em um botão em um controle GridView.

public:
 event System::Web::UI::WebControls::GridViewCommandEventHandler ^ RowCommand;

public event System.Web.UI.WebControls.GridViewCommandEventHandler RowCommand;

member this.RowCommand : System.Web.UI.WebControls.GridViewCommandEventHandler

Public Custom Event RowCommand As GridViewCommandEventHandler

Tipo de evento

GridViewCommandEventHandler

Exemplos

Um projeto de site do Visual Studio com código-fonte está disponível para acompanhar este tópico: Download.

O exemplo a seguir demonstra como usar o RowCommand evento para adicionar o nome de um cliente de um GridView controle a um ListBox controle quando o botão Adicionar de uma linha é clicado.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void ContactsGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
    // If multiple buttons are used in a GridView control, use the
    // CommandName property to determine which button was clicked.
    if(e.CommandName=="Add")
    {
      // Convert the row index stored in the CommandArgument
      // property to an Integer.
      int index = Convert.ToInt32(e.CommandArgument);

      // Retrieve the row that contains the button clicked 
      // by the user from the Rows collection.
      GridViewRow row = ContactsGridView.Rows[index];

      // Create a new ListItem object for the contact in the row.     
      ListItem item = new ListItem();
      item.Text = Server.HtmlDecode(row.Cells[2].Text) + " " +
        Server.HtmlDecode(row.Cells[3].Text);

      // If the contact is not already in the ListBox, add the ListItem 
      // object to the Items collection of the ListBox control. 
      if (!ContactsListBox.Items.Contains(item))
      {
        ContactsListBox.Items.Add(item);
      }
    }
  }    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridView RowCommand Example</h3>

      <table width="100%">
        <tr>
          <td style="width:50%">

            <asp:gridview id="ContactsGridView" 
              datasourceid="ContactsSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="ContactsGridView_RowCommand"
              runat="server">

              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="ContactID" 
                  headertext="Contact ID"/>
                <asp:boundfield datafield="FirstName" 
                  headertext="First Name"/> 
                <asp:boundfield datafield="LastName" 
                  headertext="Last Name"/>
              </columns>

            </asp:gridview>

          </td>

          <td style="vertical-align:top; width:50%">

            Contacts: <br/>
            <asp:listbox id="ContactsListBox"
              runat="server" Height="200px" Width="200px"/>

          </td>
        </tr>
      </table>

      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:sqldatasource id="ContactsSource"
        selectcommand="Select [ContactID], [FirstName], [LastName] From Person.Contact"
        connectionstring="<%$ ConnectionStrings:AdventureWorks_DataConnectionString%>" 
        runat="server"/>

    </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub ContactsGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)

    ' If multiple buttons are used in a GridView control, use the
    ' CommandName property to determine which button was clicked.
    If e.CommandName = "Add" Then
    
      ' Convert the row index stored in the CommandArgument
      ' property to an Integer.
      Dim index As Integer = Convert.ToInt32(e.CommandArgument)
            
      ' Retrieve the row that contains the button clicked 
      ' by the user from the Rows collection.
      Dim row As GridViewRow = ContactsGridView.Rows(index)
            
      ' Create a new ListItem object for the contact in the row.     
      Dim item As New ListItem()
      item.Text = Server.HtmlDecode(row.Cells(2).Text) & " " & _
        Server.HtmlDecode(row.Cells(3).Text)
            
      ' If the contact is not already in the ListBox, add the ListItem 
      ' object to the Items collection of the ListBox control. 
      If Not ContactsListBox.Items.Contains(item) Then
      
        ContactsListBox.Items.Add(item)
        
      End If
      
    End If
    
  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head id="Head1" runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridView RowCommand Example</h3>

      <table width="100%">
        <tr>
          <td style="width:50%">

            <asp:gridview id="ContactsGridView" 
              datasourceid="ContactsSource"
              allowpaging="true" 
              autogeneratecolumns="false"
              onrowcommand="ContactsGridView_RowCommand"
              runat="server">

              <columns>
                <asp:buttonfield buttontype="Link" 
                  commandname="Add" 
                  text="Add"/>
                <asp:boundfield datafield="ContactID" 
                  headertext="Contact ID"/>
                <asp:boundfield datafield="FirstName" 
                  headertext="First Name"/> 
                <asp:boundfield datafield="LastName" 
                  headertext="Last Name"/>
              </columns>

            </asp:gridview>

          </td>

          <td style="vertical-align:top; width:50%">

            Contacts: <br/>
            <asp:listbox id="ContactsListBox"
              runat="server" Height="200px" Width="200px"/>

          </td>
        </tr>
      </table>

      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:sqldatasource id="ContactsSource"
        selectcommand="Select [ContactID], [FirstName], [LastName] From Person.Contact"
        connectionstring="<%$ ConnectionStrings:AdventureWorks_DataConnectionString%>" 
        runat="server"/>

    </form>
  </body>
</html>

O exemplo a seguir demonstra como usar o RowCommand evento para atualizar o preço de um produto quando um botão de linha é clicado. Este exemplo tem a funcionalidade de paginação habilitada para o GridView controle e define a CommandArgument propriedade do controle como o índice de Button linha apropriado.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void ProductsGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
    // If multiple buttons are used in a GridView control, use the
    // CommandName property to determine which button was clicked.
    if(e.CommandName=="Increase")
    {
      // Convert the row index stored in the CommandArgument
      // property to an Integer.
      int index = Convert.ToInt32(e.CommandArgument);

      // Retrieve the row that contains the button clicked 
      // by the user from the Rows collection.      
      GridViewRow row = ProductsGridView.Rows[index];

      // Calculate the new price.
      Label listPriceTextBox = (Label)row.FindControl("PriceLabel");
      listPriceTextBox.Text = (Convert.ToDouble(listPriceTextBox.Text) * 1.05).ToString();     

      // Update the row.
      ProductsGridView.UpdateRow(index, false);
    }
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridView RowCommand Example</h3>

      <asp:GridView id="ProductsGridView" 
        DataSourceID="ProductsDataSource"
        DataKeyNames="ProductID"
        AllowPaging="True" 
        OnRowCommand="ProductsGridView_RowCommand"
        AutoGenerateColumns="False"
        runat="server">
        <Columns>
          <asp:BoundField DataField="Name" HeaderText="Product Name" />
          <asp:BoundField DataField="ProductNumber" HeaderText="Product Number" />          
          <asp:TemplateField HeaderText="Price">
            <ItemTemplate>
              <asp:Label ID="PriceLabel" runat="server" 
                Text='<%# Bind("ListPrice") %>'>
              </asp:Label>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:TemplateField>
            <ItemTemplate>                
              <asp:Button runat="server" ID="IncreaseButton"
                Text="Increase Price 5%"
                CommandName="Increase"
                CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
            </ItemTemplate>
          </asp:TemplateField>
        </Columns>
      </asp:GridView>

      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:SqlDataSource id="ProductsDataSource"
        SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [ListPrice] 
          FROM Production.Product 
          WHERE ListPrice <> 0"
        UpdateCommand="UPDATE Production.Product SET [ListPrice] = @ListPrice 
          WHERE [ProductID] = @ProductID"
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        runat="server" />

    </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">


  Sub ProductsGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)

    ' If multiple buttons are used in a GridView control, use the
    ' CommandName property to determine which button was clicked.
    If e.CommandName = "Increase" Then
    
      ' Convert the row index stored in the CommandArgument
      ' property to an Integer.
      Dim index = Convert.ToInt32(e.CommandArgument)
            
      ' Retrieve the row that contains the button clicked 
      ' by the user from the Rows collection.
      Dim row = ProductsGridView.Rows(index)
      
      ' Calculate the new price.
      Dim listPriceTextBox = CType(row.FindControl("PriceLabel"), Label)
      listPriceTextBox.Text = (Convert.ToDouble(listPriceTextBox.Text) * 1.05).ToString()

      ' Update the row.
      ProductsGridView.UpdateRow(index, False)
      
    End If
    
  End Sub
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowCommand Example</title>
</head>
<body>
    <form id="form1" runat="server">

      <h3>GridView RowCommand Example</h3>

      <asp:GridView id="ProductsGridView" 
        DataSourceID="ProductsDataSource"
        DataKeyNames="ProductID"
        AllowPaging="True" 
        OnRowCommand="ProductsGridView_RowCommand"
        AutoGenerateColumns="False"
        runat="server">
        <Columns>
          <asp:BoundField DataField="Name" HeaderText="Product Name" />
          <asp:BoundField DataField="ProductNumber" HeaderText="Product Number" />          
          <asp:TemplateField HeaderText="Price">
            <ItemTemplate>
              <asp:Label ID="PriceLabel" runat="server" 
                Text='<%# Bind("ListPrice") %>'>
              </asp:Label>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:TemplateField>
            <ItemTemplate>                
              <asp:Button runat="server" ID="IncreaseButton"
                Text="Increase Price 5%"
                CommandName="Increase"
                CommandArgument="<%# CType(Container, GridViewRow).RowIndex %>" />
            </ItemTemplate>
          </asp:TemplateField>
        </Columns>
      </asp:GridView>

      <!-- This example uses Microsoft SQL Server and connects    -->
      <!-- to the AdventureWorks sample database. Use an ASP.NET  -->
      <!-- expression to retrieve the connection string value     -->
      <!-- from the Web.config file.                              -->
      <asp:SqlDataSource id="ProductsDataSource"
        SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [ListPrice] 
          FROM Production.Product 
          WHERE ListPrice <> 0"
        UpdateCommand="UPDATE Production.Product SET [ListPrice] = @ListPrice 
          WHERE [ProductID] = @ProductID"
        ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
        runat="server" />

    </form>
  </body>
</html>

Comentários

O RowCommand evento é gerado quando um botão é clicado no GridView controle . Isso permite que você forneça um método de manipulação de eventos que executa uma rotina personalizada sempre que esse evento ocorre.

Botões dentro de um GridView controle também podem invocar algumas das funcionalidades internas do controle. Para executar uma dessas operações, defina a CommandName propriedade de um botão como um dos valores na tabela a seguir.

`CommandName` valor	Descrição
"Cancelar"	Cancela uma operação de edição e retorna o controle para o GridView modo somente leitura. Aciona o evento RowCancelingEdit.
"Excluir"	Exclui o registro atual. Gera os RowDeleting eventos e RowDeleted .
"Editar"	Coloca o registro atual no modo de edição. Aciona o evento RowEditing.
"Página"	Executa uma operação de paginação. Define a `CommandArgument` propriedade do botão como "First", "Last", "Next", "Prev" ou um número de página para especificar o tipo de operação de paginação a ser executada. Gera os PageIndexChanging eventos e PageIndexChanged .
"Selecionar"	Seleciona o registro atual. Gera os SelectedIndexChanging eventos e SelectedIndexChanged .
"Classificar"	Classifica o controle GridView . Gera os Sorting eventos e Sorted .
"Atualizar"	Atualiza o registro atual na fonte de dados. Gera os RowUpdating eventos e RowUpdated .

Embora o RowCommand evento seja gerado quando um botão listado na tabela anterior é clicado, é recomendável que você use os eventos listados na tabela para a operação.

Um GridViewCommandEventArgs objeto é passado para o método de manipulação de eventos, que permite determinar o nome do comando e o argumento de comando do botão clicado.

Observação

Para determinar o índice da linha que gerou o evento, use a CommandArgument propriedade do argumento event que é passado para o evento. A ButtonField classe preenche automaticamente a CommandArgument propriedade com o valor de índice apropriado. Para outros botões de comando, você deve definir manualmente a CommandArgument propriedade do botão de comando. Por exemplo, você pode definir o CommandArgument como <%# Container.DataItemIndex %> quando o GridView controle não tiver nenhuma paginação habilitada.

Para obter mais informações sobre como lidar com eventos, consulte Manipulando e levantando eventos.

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