/// <summary>
/// Blows up because trying to access GUI from wrong context.
/// </summary>
/// <param name="parameter"></param>
public async void Execute(object parameter)
{
TheViewModel vm = parameter as TheViewModel;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
//Switching to default context here.
string msg = await CallSomethingAsync(vm).ConfigureAwait(continueOnCapturedContext: false);
//Still on default context, no access to GUI thread. Boom.
vm.UpdateDescription(msg);
}
/// <summary>
/// Works because we never switch contexts
/// </summary>
/// <param name="parameter"></param>
public async void Execute(object parameter)
{
TheViewModel vm = parameter as TheViewModel;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
//Remains context aware
string msg = await CallSomethingAsync(vm);
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
vm.UpdateDescription(msg);
}
/// <summary>
/// Deadlocks
/// </summary>
/// <param name="parameter"></param>
public void Execute(object parameter)
{
TheViewModel vm = parameter as TheViewModel;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
//Blocks while CallSomethingAsync runs. CallSomethingAsync
//cannot resume on the context because .Result is blocking.
var msg = CallSomethingAsync(vm);
vm.UpdateDescription(msg.Result);
}
/// <summary>
/// Deadlocks
/// </summary>
/// <param name="parameter"></param>
public void Execute(object parameter)
{
TheViewModel vm = parameter as TheViewModel;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
//Blocks while CallSomethingAsync runs.
string msg = CallSomethingAsync(vm).Result;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
vm.UpdateDescription(msg);
}
/// <summary>
/// Work is done on default context but is resumed on the
/// captured context.
/// </summary>
/// <param name="parameter"></param>
public async void Execute(object parameter)
{
TheViewModel vm = parameter as TheViewModel;
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
//No ConfigureAwait False here! The work in that method DOES
//operate on a different conext but execution will resume
//on the original context so we can access the GUI thread.
string msg = await CallSomethingAsync(vm);
vm.UpdateDescription(msg);
vm.CurrentThreadID = Thread.CurrentThread.ManagedThreadId;
}
