ConfigureAwait(false) with UI controls?

Question

Is it OK to use .ConfigureAwait(false) for the following two code snippets?

Case 1

var ds = new BindingSource();
ds.DataSource = await CallAsync(); // .ConfigureAwait(false);
UIControl.DataSource = ds;

Case 2

UIControl.DataSource = new BindingSource
{
    DataSource = await CallAsync() // .ConfigureAwait(false)
};

Does the first one seem to have the problem of set UI control at the background thread? How about the second one?

It's not clear why you are considering `ConfigureAwait(false)` in this, well, *context*. Is it about `CallAsync()` not being that much *async*? Are you using `Task.Run()` in the implementation of a not-so-much `async` method? Maybe it's just partially `async`? — Jimi, Mar 02 '19 at 15:29

score 2 · Accepted Answer · edited Mar 02 '19 at 05:08

2

All access to controls should be done in the same thread which the control is created.

By calling ConfigureAwait(false) you are asking not to attempt to marshal the continuation back to the original context captured. It means the code continue the execution in a different context than the UI thread which is invalid operation.

So, the answer is yes, both above cases have problem and will result in:

InvalidOperationException: Cross-thread operation not valid: Control 'Control Name' accessed from a thread other than the thread it was created on.

edited Mar 02 '19 at 05:08

NGambit

1,141
13
27

answered Mar 02 '19 at 04:52

Reza Aghaei

120,393
18
203
398

Data binding cannot generate that exception, notorious problem. – Hans Passant Mar 02 '19 at 08:58
@HansPassant Do you mean the cases which are mentioned in the question or some different cases? (I've already tested question cases and they throw exception.) – Reza Aghaei Mar 02 '19 at 10:17

ConfigureAwait(false) with UI controls?

1 Answers1

Linked