BackgroundWorker.IsBusy 属性

定义

命名空间:

System.ComponentModel

程序集:

System.ComponentModel.EventBasedAsync.dll

Source:

BackgroundWorker.cs

获取一个值，指示 BackgroundWorker 是否正在运行异步操作。

C#

public bool IsBusy { get; }

属性值

Boolean

如果 BackgroundWorker 正在运行异步操作，则为 true；否则为 false。

示例

下面的代码示例演示如何使用 IsBusy 属性等待操作完成 BackgroundWorker 。 此代码示例是 如何：在后台下载文件中所述的较大示例的一部分。

C#

private void downloadButton_Click(object sender, EventArgs e)
{
    // Start the download operation in the background.
    this.backgroundWorker1.RunWorkerAsync();

    // Disable the button for the duration of the download.
    this.downloadButton.Enabled = false;

    // Once you have started the background thread you 
    // can exit the handler and the application will 
    // wait until the RunWorkerCompleted event is raised.

    // Or if you want to do something else in the main thread,
    // such as update a progress bar, you can do so in a loop 
    // while checking IsBusy to see if the background task is
    // still running.

    while (this.backgroundWorker1.IsBusy)
    {
        progressBar1.Increment(1);
        // Keep UI messages moving, so the form remains 
        // responsive during the asynchronous operation.
        Application.DoEvents();
    }
}

注解

调用 RunWorkerAsync时， BackgroundWorker 将启动异步操作。

适用于

另请参阅

• RunWorkerCompleted
• EventArgs
• RunWorkerAsync
• 如何：在后台运行操作
• 如何：在后台下载文件