How to make BackgroundWorker ProgressChanged events execute in sequence?

Question

Consider the following code:

private static BackgroundWorker bg = new BackgroundWorker();

static void Main(string[] args) {
  bg.DoWork += bg_DoWork;
  bg.P         


        

Answer 1

BackgroundWorker raises ProgressChanged events on the current SynchronizationContext of the thread that called RunWorkerAsync().

The default SynchronizationContext runs callbacks on the ThreadPool without any synchronization.

If you use BackgroundWorker in a UI application (WPF or WinForms), it will use that UI platform's SynchronizationContext, which will execute callbacks in order.