问从多个工作线程(.NET)更新UI

EN

BackgroundWorker bw = new BackgroundWorker();
bw.WorkerReportsProgress = true;
bw.DoWork += /* your background work here */;
bw.ProgressChanged += /* your UI update method here */;
bw.RunWorkerAsync();

public partial class MultithreadingForm : Form
{
    public MultithreadingForm()
    {
        InitializeComponent();
    }

    // a simple button event handler that starts a worker thread
    private void btnDoWork_Click(object sender, EventArgs e)
    {
        Thread t = new Thread(WorkerMethod);
        t.Start();
    }

    private void ReportProgress(string message)
    {
        // check whether or not the current thread is the main UI thread
        // if not, InvokeRequired will be true
        if (this.InvokeRequired)
        {
            // create a delegate pointing back to this same function
            // the Invoke method will cause the delegate to be invoked on the main UI thread
            this.Invoke(new Action<string>(ReportProgress), message);
        }
        else
        {
            // txtOutput is a UI control, therefore it must be updated by the main UI thread
            if (string.IsNullOrEmpty(this.txtOutput.Text))
                this.txtOutput.Text = message;
            else
                this.txtOutput.Text += "\r\n" + message;
        }
    }

    // a generic method that does work and reports progress
    private void WorkerMethod()
    {
        // step 1
        // ...
        ReportProgress("Step 1 completed");

        // step 2
        // ...
        ReportProgress("Step 2 completed");

        // step 3
        // ...
        ReportProgress("Step 3 completed");
    }
}