Question

我已经查看了msdn以及有关如何使用后台工作者的堆栈交换的类似问题。

基本上，我的函数upload-program完成了实际的工作，但是我想要一个线程来改变ui的元素（进度条等），并且当我发送事件以改变进度时。我尝试的是下面（严格编辑），它不起作用，程序似乎在调用runworkerasync后切断。是否有一些简单的错误或将命令“发送到另一个线程”是错误的？

BackgroundWorker backgroundUpload = new System.ComponentModel.BackgroundWorker();

第一位是电话：

        if (backgroundUpload.IsBusy != true)
        {
            backgroundUpload.RunWorkerAsync(work);
                 // a command here for debug purposes (eg a message box) will run
        }
        else
        { //it doesn't go here, this isn't the error}

然后是笨蛋，它似乎永远不会到达这里。

    private void backgroundUpload_DoWork(object sender, DoWorkEventArgs e)
    {
        BackgroundWorker worker = sender as BackgroundWorker;
        e.Result = UploadProgram((Workload)e.Argument, worker, e); //workload is one of my enums
    }

似乎永远不会到达这里。

bool UploadProgram(Workload work, BackgroundWorker worker, DoWorkEventArgs e)
    {
    }

    //also there is progress changed and run worker complete.

Answer 1

您是否为活动订阅了活动处理程序？

BackgroundWorker backgroundUpload = new System.ComponentModel.BackgroundWorker();
backgroundUpload.DoWork += backgroundUpload_DoWork;

Answer 2

愚蠢的问题，但你确定你订阅了这个活动吗？

backgroundUpload.DoWork += backgroundUpload_DoWork;

Here is a complete example, downloading a file

Answer 3

在您的代码中缺少让BackgroundWorker与UI进行通信所需的管道

您需要确保正确设置这些属性和事件

 .....
 backgroundUpload.DoWork += backgroundUpload_DoWork
 backgroundUpload.ProgressChanged += backgroundUpload_ProgressChanged;
 backgroundUpload.WorkerReportsProgress = true;
 .....

您需要在更新进度条的UI线程上运行事件处理程序

private void backgroundUpload_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar.Value = (e.ProgressPercentage.ToString() + "%");
}

当您尝试上传文件时

 worker.ReportProgress(percentComplete);

另一个背景工人

3 个答案: