c# winform background worker and progress bar

问题:

I am trying to get the progress bar to increment using a BG Worker. I am currently using 2 BG workers, one to add data into a DB and one for the progress bar. The DB upload is working fine, yet the progress bar is not.

Code:

BackgroundWorker bg2 = new BackgroundWorker();
bg2.DoWork +=new DoWorkEventHandler(bg2_DoWork);
bg2.RunWorkerAsync();

void bg2_DoWork(object sender, DoWorkEventArgs e)
    {

        while (bg1.IsBusy)
            DrawWellPlate.pbar.Increment(1)
    }

bg1 that it refers to is the database upload thread and pbar is clearly the progress bar.

Thanks.

回答1:

You should do something like this where totalProgress will be shown in progressBar, doWork is executed not in UI thread, that is the purpose of BackgroundWorker

BackgroundWorker bg2 = new BackgroundWorker();
bg2.DoWork +=new DoWorkEventHandler(bg2_DoWork);
.ProgressChanged += new ProgressChangedEventHandler(bg2_ProgressChanged)
bg2.RunWorkerAsync();

void bg2_DoWork(object sender, DoWorkEventArgs e)
    {

        while (bg1.IsBusy)
            worker.ReportProgress(totalProgress);
    }
private void bg2_ProgressChanged(object sender,
            ProgressChangedEventArgs e)
        {
            DrawWellPlate.pbar.Value = e.ProgressPercentage;
        }

see this for more details

回答2:

The issue is that bg1 will always report that it is busy while it runs its DoWork method.

You should use just ONE background worker and in its do work method something like this (pseudo code):

void bg1_DoWork(object sender, DoWorkEventArgs e)
{
    while(got_stuff_to_add_to_the_database)
    {
       //do *some* of the work
       AddABit()

       //Update the progress - 5% at a time?
       totalProgress += 5

       //update the progress bar
       ReportProgress(totalProgress)

       if(finished)
       {
           got_stuff_to_add_to_the_database = false;
       }
    }
}