public void AssignCommandToButton()
{
CommandProvider.OnClickCount = 0;
TestViewModel viewModel = new TestViewModel();
using(var button = new Button()) {
button.SetCommand(viewModel.TestCommand);
Assert.That(viewModel.TestCommandExecuteCount, Is.EqualTo(0));
button.PerformClick();
Assert.That(viewModel.TestCommandExecuteCount, Is.EqualTo(1));
Assert.That(viewModel.ExecuteParameter, Is.Null);
Assert.That(viewModel.CanExecuteParameter, Is.Null);
Assert.That(CommandProvider.OnClickCount, Is.EqualTo(1));
button.SetCommand(null);
button.PerformClick();
Assert.That(viewModel.TestCommandExecuteCount, Is.EqualTo(1));
Assert.That(CommandProvider.OnClickCount, Is.EqualTo(1));
viewModel.CanExecuteTestCommand = false;
button.SetCommand(viewModel.TestCommand);
button.PerformClick();
Assert.That(viewModel.TestCommandExecuteCount, Is.EqualTo(1));
Assert.That(CommandProvider.OnClickCount, Is.EqualTo(1));
viewModel.CanExecuteTestCommand = true;
button.SetCommandParameter("param");
button.PerformClick();
Assert.That(viewModel.TestCommandExecuteCount, Is.EqualTo(2));
Assert.That(viewModel.ExecuteParameter, Is.EqualTo("param"));
Assert.That(viewModel.CanExecuteParameter, Is.EqualTo("param"));
Assert.That(CommandProvider.OnClickCount, Is.EqualTo(2));
}
}
public void UpdateIsEnabledOnCanExecuteChanged()
{
bool canExecute = true;
bool executed = false;
var command = new DelegateCommand<string>(o => executed = true, o => canExecute);
using(var button = new Button()) {
button.SetCommand(command);
Assert.That(button.Enabled, Is.True);
canExecute = false;
Assert.That(button.Enabled, Is.True);
button.PerformClick();
Assert.That(executed, Is.False);
Assert.That(button.Enabled, Is.True);
TestUtils.GarbageCollect();
command.RaiseCanExecuteChanged();
Assert.That(button.Enabled, Is.False);
Assert.That(command.CanExecuteChangedSubscribeCount, Is.EqualTo(1));
WeakReference handlerRef = GetHandlerRef(button);
button.SetCommand(null);
Assert.That(command.CanExecuteChangedSubscribeCount, Is.EqualTo(0));
TestUtils.GarbageCollect();
Assert.That(handlerRef.IsAlive, Is.False);
}
}
WeakReference CreateButtonAndAssignCommand(ICommand command)
{
var button = new Button();
button.SetCommand(command);
return new WeakReference(button);
}
public void UpdateIsEnabledOnSetParameter()
{
var command = new DelegateCommand<string>(o => { }, o => string.IsNullOrEmpty(o));
using(var button = new Button()) {
button.SetCommand(command);
Assert.That(button.Enabled, Is.True);
button.SetCommandParameter("x");
Assert.That(button.Enabled, Is.False);
button.SetCommandParameter(null);
Assert.That(button.Enabled, Is.True);
button.SetCommandParameter("x");
Assert.That(button.Enabled, Is.False);
button.SetCommand(null);
Assert.That(button.Enabled, Is.True);
button.SetCommand(command);
Assert.That(button.Enabled, Is.False);
}
}