System.Waf.Applications.AsyncDelegateCommand.CanExecute C# (CSharp) 메소드

        public bool CanExecute(object parameter)
        {
            return !IsExecuting && (canExecute == null || canExecute(parameter));
        }

        public void CanExecuteDuringAsyncExecute2()
        {
            var tcs = new TaskCompletionSource<object>();
            var canExecute = false;
            var executeCalled = false;

            var command = new AsyncDelegateCommand(() =>
            {
                executeCalled = true;
                return tcs.Task;
            }, () => canExecute);

            Assert.IsFalse(command.CanExecute(null));
            command.Execute(null);
            Assert.IsFalse(executeCalled);

            canExecute = true;
            Assert.IsTrue(command.CanExecute(null));
            command.Execute(null);

            executeCalled = false;
            Assert.IsFalse(command.CanExecute(null));
            command.Execute(null);
            Assert.IsFalse(executeCalled);

            tcs.SetResult(null);
            Assert.IsTrue(command.CanExecute(null));
            command.Execute(null);
            Assert.IsTrue(executeCalled);
        }