BackgroundWorker Not working in VSTO

问题

I have a background worker. Before I invoke the worker I disable a button and make a gif visible. I then invoke the runworkerasync method and it runs fine until comleteion. On the 'RunWorkerCompleted()' I get a cross thread error. Any idea why?

    private void buttonRun_Click(object sender, EventArgs e)
    {
        if (comboBoxFiscalYear.SelectedIndex != -1 && !string.IsNullOrEmpty(textBoxFolderLoc.Text))
        {
            try
            {
                u = new UpdateDispositionReports(
                    Convert.ToInt32(comboBoxFiscalYear.SelectedItem.ToString())
                    , textBoxFolderLoc.Text
                    , Properties.Settings.Default.TemplatePath
                    , Properties.Settings.Default.ConnStr);
                this.buttonRun.Enabled = false;
                this.pictureBox1.Visible = true;

                BackgroundWorker bw = new BackgroundWorker();
                bw.DoWork += new DoWorkEventHandler(bw_DoWork);
                bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
                bw.RunWorkerAsync();
                //backgroundWorker1.RunWorkerAsync();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Unable to process.\nError:" + ex.Message, Properties.Settings.Default.AppName);
            }
        }
    }

    void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        buttonRun.Enabled = true;
        pictureBox1.Visible = false;
    }

    void bw_DoWork(object sender, DoWorkEventArgs e)
    {
        u.Execute();
    }

回答1:

It seems to be an issue with VSTO and BackgroundWorker.

The solution is here.

Basically you need to call

System.Threading.SynchronizationContext.SetSynchronizationContext(new WindowsFormsSynchronizationContext());

before you call RunWorkerAsync. Works great.

To avoid instantiating the object every time you may have a static member in you AddIn's main class and reuse it. This way you only instantiate once.

回答2:

something about VSTO running the background worker on the same thread as the controls. Not sure. I had to check the InvokeRequired

    private void buttonRun_Click(object sender, EventArgs e)
    {
        if (comboBoxFiscalYear.SelectedIndex != -1 && !string.IsNullOrEmpty(textBoxFolderLoc.Text))
        {
            try
            {
                u = new UpdateDispositionReports(
                    Convert.ToInt32(comboBoxFiscalYear.SelectedItem.ToString())
                    , textBoxFolderLoc.Text
                    , Properties.Settings.Default.TemplatePath
                    , Properties.Settings.Default.ConnStr);
                this.buttonRun.Enabled = false;
                this.pictureBox1.Visible = true;

                BackgroundWorker bw = new BackgroundWorker();
                bw.DoWork += new DoWorkEventHandler(bw_DoWork);
                bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bw_RunWorkerCompleted);
                bw.RunWorkerAsync();
                //backgroundWorker1.RunWorkerAsync();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Unable to process.\nError:" + ex.Message, Properties.Settings.Default.AppName);
            }
        }
    }
    delegate void ReenableRunCallback();

    private void ReenableRun()
    {
        if (this.buttonRun.InvokeRequired)
        {
            ReenableRunCallback r = new ReenableRunCallback(ReenableRun);
            this.buttonRun.Invoke(r, null);
        }
        else
            this.buttonRun.Enabled = true;
    }
    private void HideProgress()
    {
        if (this.pictureBox1.InvokeRequired)
        {
            ReenableRunCallback r = new ReenableRunCallback(HideProgress);
            this.pictureBox1.Invoke(r, null);
        }
        else
            this.pictureBox1.Visible = false;
    }

    void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        ReenableRun();
        HideProgress();
    }

    void bw_DoWork(object sender, DoWorkEventArgs e)
    {
        u.Execute();
    }

来源：https://stackoverflow.com/questions/2449515/backgroundworker-not-working-in-vsto

标签

vsto

backgroundworker