GridViewDeletedEventArgs.ExceptionHandled Eigenschaft

  • Referenz

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Ruft einen Wert ab, der angibt, ob während der Behandlung des Löschvorgangs im Ereignishandler eine Ausnahme ausgelöst wurde, oder legt diesen Wert fest.

public:
 property bool ExceptionHandled { bool get(); void set(bool value); };
public bool ExceptionHandled { get; set; }
member this.ExceptionHandled : bool with get, set
Public Property ExceptionHandled As Boolean

Eigenschaftswert

Boolean

true, wenn die Ausnahme im Ereignishandler behandelt wurde, andernfalls false. Der Standardwert ist false.

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie die ExceptionHandled -Eigenschaft verwendet wird, um anzugeben, dass die Ausnahme im Ereignishandler behandelt wurde.


<%@ 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 CustomersGridView_RowDeleted(Object sender, GridViewDeletedEventArgs e)
  {

    // Use the Exception property to determine whether an exception
    // occurred during the delete operation.
    if (e.Exception == null)
    {
      // Use the AffectedRows property to determine whether the
      // record was deleted. Sometimes an error might occur that 
      // does not raise an exception, but prevents the delete
      // operation from completing.
      if (e.AffectedRows == 1)
      {
        Message.Text = "Record deleted successfully.";
      }
      else
      {
        Message.Text = "An error occurred during the delete operation.";
      }
    }
    else
    {
      // Insert the code to handle the exception.
      Message.Text = "An error occurred during the delete operation.";

      // Use the ExceptionHandled property to indicate that the 
      // exception is already handled.
      e.ExceptionHandled = true;
    }
    
  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridViewDeletedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridViewDeletedEventArgs Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"          
        runat="server"/>
                
      <br/>
            
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames property as read-only.    -->
      <!-- No input controls are rendered for these columns in     -->
      <!-- edit mode.                                              -->
      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogeneratedeletebutton="true"
        datakeynames="CustomerID"
        onrowdeleted="CustomersGridView_RowDeleted"  
        runat="server">
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        deletecommand="Delete from Customers where CustomerID = @CustomerID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
      
    </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 CustomersGridView_RowDeleted(ByVal sender As Object, ByVal e As GridViewDeletedEventArgs)

    ' Use the Exception property to determine whether an exception
    ' occurred during the delete operation.
    If e.Exception Is Nothing Then

      ' Use the AffectedRows property to determine whether the
      ' record was deleted. Sometimes an error might occur that 
      ' does not raise an exception, but prevents the delete
      ' operation from completing.
      If e.AffectedRows = 1 Then
      
        Message.Text = "Record deleted successfully."
      
      Else
      
        Message.Text = "An error occurred during the delete operation."
      
      End If
    
    Else
          
      ' Insert the code to handle the exception.
      Message.Text = "An error occurred during the delete operation."

      ' Use the ExceptionHandled property to indicate that the 
      ' exception is already handled.
      e.ExceptionHandled = True
    
    End If
    
  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridViewDeletedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridViewDeletedEventArgs Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"          
        runat="server"/>
                
      <br/>
            
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames property as read-only.    -->
      <!-- No input controls are rendered for these columns in     -->
      <!-- edit mode.                                              -->
      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogeneratedeletebutton="true"
        datakeynames="CustomerID"
        onrowdeleted="CustomersGridView_RowDeleted"  
        runat="server">
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        deletecommand="Delete from Customers where CustomerID = @CustomerID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
      
    </form>
  </body>
</html>

Hinweise

Wenn während des Löschvorgangs eine Ausnahme ausgelöst wird, geben Sie mit der ExceptionHandled -Eigenschaft an, ob die Ausnahme im Ereignishandler behandelt wurde. Wenn diese Eigenschaft auf truefestgelegt ist, gilt die Ausnahme als behandelt und wird nicht erneut ausgelöst. Wenn diese Eigenschaft auf falsefestgelegt ist, löst das GridView Steuerelement die Ausnahme erneut aus. Verwenden Sie die Exception -Eigenschaft, um zu bestimmen, welche Ausnahme ausgelöst wurde.

Gilt für:

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