/// <summary>
/// In this case this event, unlike the event above is called from
/// a different thread, without InvokeIfRequired in WinFormsExtensionLibrary
/// a exception would be thrown "cross thread operation not valid".
///
/// InvokeIfRequired language extension is basic code to check if Invoke
/// needs to be called and if so uses Invoke and if not simple executes
/// the action, in this case setting Text property of a label.
///
/// In DataGridViewLoadDelimitedFileAsynchronous.Form1 Example1Button_Click
/// several lines of code are executes as an Action for InvokeIfRequired.
///
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private void Ops_OnIterate2(object sender, ProcessIndexingArgs args)
{
/*
* It's unsafe to call a control directly from a thread that didn't create it which happens
* in this case setting ProcessStatus2Label.Text directly, instead the extension method
* InvokeIfRequired ensuring thread-safe call is made to ProcessStatus2Label.
*
* InvokeIfRequired extension method is used in other code samples in this Visual Studio solution.
* By using InvokeIfRequired creates uniformity when an Action is required in the calling thread.
*
*/
if (EnableCrossThreadButton.Checked)
{
ProcessStatus2Label.Text = args.ToString();
}
else
{
ProcessStatus2Label.InvokeIfRequired(d => { ProcessStatus2Label.Text = args.ToString(); });
}
}
/// <summary>
/// Show progress on code executed in ProcessAsync1Button. Since in this
/// example we are not using ConfigureAwait(false) this code executes
/// in the same thread so not cross
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private void OnIterateLoop1(object sender, ProcessIndexingArgs args)
{
ProcessStatus1Label.Text = args.ToString();
}
