Avoids to fall into the deadlock in `Form.FormClose` when using `Invoke` by worker thread of the `Form` in DotNet 2.0.

AvoidsFormInvokingDeadlock.cs

public partial class MainForm : Form {
    // Avoids dead lock problem when closed in invoking
    private bool invoking = false;
    private bool closeRequested = false;
    public new object Invoke(Delegate program) {
    object ret = null;
    if (!closeRequested) {
        invoking = true;
        try {
            ret = base.Invoke(program);
            if (closeRequested) {
                    base.BeginInvoke((MethodInvoker)delegate { Close(); });
                }
            } catch (ObjectDisposedException) {
            } finally {
                invoking = false;
            }
        }
        return ret;
    }
    private bool ShouldBeFormCloseDeferred() {
        if (invoking) {
            closeRequested = true;
            return true;
        }
        return false;
    }
    private void MainForm_FormClosing(object sender, FormClosingEventArgs e) {
        if (ShouldBeFormCloseDeferred()) {
            e.Cancel = true;
            return;
        }
        // ...
    }
    // ...
}