Sandbox.TaskSource.IsValid

Sandbox.TaskSource.IsValid : api/Sandbox.TaskSource/IsValid

Indicates whether async logic is still allowed to continue.

This is best used for loop conditions or to guard sync work before the first await.

there is no need to check this after awaiting since cancellation is enforced automatically.

Example:

while ( ts.IsValid )
{
    await ts.Frame();
    UpdateLogic();
}