Question

我正在执行大量插入操作，我想添加一个进度条。使用Parallel ForEach，我收到以下错误：

“Microsoft.VisualStudio.Debugger.Runtime.CrossThreadMessagingException”

progressbar1一个levéuneexception de type'Microsoft.VisualStudio.Debugger.Runtime.CrossThreadMessagingException

private void button1_Click(object sender, EventArgs e)
{
    textBox4.Text = richTextBox1.Lines.Length.ToString(); 
    DateTime start = DateTime.Now;
    TimeSpan timediff = new TimeSpan();

    progressBar1.Maximum = i;
    progressBar1.Minimum = 0;
    progressBar1.Step = 1;

    int j = 1;
    l = 0;
    k=0;
    Parallel.ForEach(richTextBox1.Lines, (line) =>
    {
        progressBar1.Value = j;
        try
        {
            string pwd = query.Querie_read("select plain from rainbow where plain='" + line.ToString() + "'");
            if (pwd != line.ToString())
            {
                fct.AddRainbow(line.ToString());
                k++;
            }
            else
            {
                l++;
            }
        }
        catch (Exception ex)
        {
            // MessageBox.Show(ex.Message);
            l++;
        }

        j++;

    });
    textBox1.Text = k.ToString();
    textBox3.Text = l.ToString();
    timediff = DateTime.Now.Subtract(start);
    textBox2.Text = timediff.ToString();

    MessageBox.Show("Finished");
}

Answer 1

UI只能从主线程（或更准确地说，创建UI的线程）更新。要在正确的线程中执行代码，请使用调度程序：

对于WPF：

this.Dispatcher.BeginInvoke(new Action(() => progressBar1.Value = j));

对于WinForm：

this.BeginInvoke(new Action(() => progressBar1.Value = j));

Answer 2

progressBar1.Invoke((MethodInvoker)(delegate() { progressBar1.Value = j; }))

并行类的CrossThread错误 - ProgressBar

2 个答案: