c# - Async with await do not work. Why? -

when try run code below, perform synchronous operations. why?

i following warning ...

warning 1 async method lacks 'await' operators , run synchronously. consider using 'await' operator await non-blocking api calls, or 'await task.run(...)' cpu-bound work on background thread.

private async void btprocessa_click(object sender, eventargs e) {     await processaa();     await processab(); }  public async task processaa() {     (int = 0; <= 100; i++)     {         pbprocessoa.value = i;         thread.sleep(500);     } }  public async task processab() {     (int = 0; <= 100; i++)     {         pbprocessob.value = i;         thread.sleep(500);     } } 

async not mean "run code on background thread". if want know more async, have introductory blog post, msdn docs great, , there's full guide task-based asynchronous pattern.

if want simulation of i/o-bound (or event-based) operations, should use task.delay instead of thread.sleep:

public async task processaa() {   (int = 0; <= 100; i++)   {     pbprocessoa.value = i;     await task.delay(500);   } } 

if want simulate cpu-bound operations, should pushing them off background task via task.run:

public async task processaa() {   (int = 0; <= 100; i++)   {     pbprocessoa.value = i;     await task.run(() => { thread.sleep(500); });   } }