BackgroundWorker的将不报告进度 [英] Backgroundworker won't report progress

问题描述

我运行一个数据库长任务后台工作。我希望任务运行时显示进度条。不知怎的，后台工作人员会不报告任务的进度。

I have a background worker running a long database task. i want to show the progress bar while the task is running. Somehow the background worker won't report the progress of the task.

这是我有：

BackgroundWorker _bgwLoadClients;

_bgwLoadClients = new BackgroundWorker();
_bgwLoadClients.WorkerReportsProgress = true;
_bgwLoadClients.DoWork += new DoWorkEventHandler(_bgwLoadClients_DoWork);
_bgwLoadClients.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_bgwLoadClients_RunWorkerCompleted);
_bgwLoadClients.ProgressChanged += new ProgressChangedEventHandler(_bgwLoadClients_ProgressChanged);
_bgwLoadClients.RunWorkerAsync(parms);

private void _bgwLoadClients_DoWork(object sender, DoWorkEventArgs e)
{
    DataTable dt = getdate();
    e.Result = dt;
}

void _bgwLoadClients_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
}

我在WPF中这样做，但我想这不会有所作为。

I am doing this in WPF, but i guess it won't make a difference.

在此先感谢

推荐答案

您需要向下打破你的DoWork方法为报告进度，然后调用ReportProgress。

You need to break your DoWork method down into reportable progress and then call ReportProgress.

举个例子如下：

private void Something_DoWork(object sender, DoWorkEventArgs e) 
{
    // If possible, establish how much there is to do
    int totalSteps = EstablishWorkload();

    for ( int i=0; i<totalSteps; i++)
    {
        // Do something...

        // Report progress, hint: sender is your worker
        (sender as BackgroundWorker).ReportProgress((int)(100/totalSteps)*i, null);
    }

}

如果你的工作不能predetermined，尝试将自己的命中率：

If your work can't be predetermined, try adding your own percentages:

private void Something_DoWork(object sender, DoWorkEventArgs e) 
{
    // some work

    (sender as BackgroundWorker).ReportProgress(25, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(50, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(60, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(99, null);
}

这篇关于BackgroundWorker的将不报告进度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！