private static async Task <T> ShowAsync <T>(Func <Task <T> > show, IDispatcherEx dispatcher)
{
await _showAsyncSemaphoreSlim.WaitAsync();
try
{
dispatcher = dispatcher ?? WindowEx.Current().Dispatcher ?? throw new ArgumentNullException(nameof(dispatcher));
return(await dispatcher.DispatchAsync(async() => await show()));
}
finally
{
_showAsyncSemaphoreSlim.Release();
}
}
