DoWorkEventArgs 类

定义

命名空间:

System.ComponentModel

程序集:

System.ComponentModel.EventBasedAsync.dll

Source:

DoWorkEvent.cs

为 DoWork 事件处理程序提供数据。

public ref class DoWorkEventArgs : System::ComponentModel::CancelEventArgs

public class DoWorkEventArgs : System.ComponentModel.CancelEventArgs

type DoWorkEventArgs = class
    inherit CancelEventArgs

Public Class DoWorkEventArgs
Inherits CancelEventArgs

继承

Object

EventArgs

CancelEventArgs

DoWorkEventArgs

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

构造函数

DoWorkEventArgs(Object)

初始化 DoWorkEventArgs 类的新实例。

属性

Argument	获取表示异步操作参数的值。
Cancel	获取或设置指示是否应取消事件的值。 (继承自 CancelEventArgs)
Result	获取或设置表示异步操作结果的值。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

另请参阅

• BackgroundWorker
• 如何：在后台运行操作