DoWorkEventArgs.Argument 属性

定义

命名空间:

System.ComponentModel

程序集:

System.ComponentModel.EventBasedAsync.dll

Source:

DoWorkEvent.cs

获取表示异步操作参数的值。

public:
 property System::Object ^ Argument { System::Object ^ get(); };

public object? Argument { get; }

member this.Argument : obj

Public ReadOnly Property Argument As Object

属性值

Object

表示异步操作参数的 Object。

示例

下面的代码示例演示如何使用 DoWorkEventArgs 类来处理 DoWork 事件。 有关完整代码列表，请参阅 如何：在后台运行操作。

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
    // Do not access the form's BackgroundWorker reference directly.
    // Instead, use the reference provided by the sender parameter.
    BackgroundWorker bw = sender as BackgroundWorker;

    // Extract the argument.
    int arg = (int)e.Argument;

    // Start the time-consuming operation.
    e.Result = TimeConsumingOperation(bw, arg);

    // If the operation was canceled by the user, 
    // set the DoWorkEventArgs.Cancel property to true.
    if (bw.CancellationPending)
    {
        e.Cancel = true;
    }
}

Private Sub backgroundWorker1_DoWork( _
sender As Object, e As DoWorkEventArgs) _
Handles backgroundWorker1.DoWork

   ' Do not access the form's BackgroundWorker reference directly.
   ' Instead, use the reference provided by the sender parameter.
   Dim bw As BackgroundWorker = CType( sender, BackgroundWorker )
   
   ' Extract the argument.
   Dim arg As Integer = Fix(e.Argument)
   
   ' Start the time-consuming operation.
   e.Result = TimeConsumingOperation(bw, arg)
   
   ' If the operation was canceled by the user, 
   ' set the DoWorkEventArgs.Cancel property to true.
   If bw.CancellationPending Then
      e.Cancel = True
   End If

End Sub

另请参阅

• BackgroundWorker
• 如何：在后台运行操作