为什么我的某些按钮在运行时被禁用？

Question

When the window is opened, Abort is clickable, but all of the other buttons are not. I put breakpoints at my getters:

public ICommand OkCommand
        {
            get { return _okCommand; }
        }

and the button is disabled after it is called. I feel like I'm missing something obvious here. Is my binding not setup correctly? Or is it not being correctly initialized?

My ViewModel constructor:

[ImportingConstructor]
        public MyViewModel(IMyViewModel view)
            : base(view)
        {
            _okCommand = new DelegateCommand(OkHandler, IsValid);
            _refreshCommand = new DelegateCommand(RefreshHandler, IsValid);
            _testConnCommand = new DelegateCommand(TestConnectionHandler, IsValid);
        }

My XAML for two of the buttons.

<StackPanel Orientation="Horizontal" Margin="0,14" HorizontalAlignment="Center" DockPanel.Dock="Bottom">
            <Button Command="{Binding OkCommand}" Content="Ok" IsDefault="True" TabIndex="3" Margin="5,0"/>
            <Button Content="Abort" IsCancel="True" TabIndex="4" Margin="0"/>
        </StackPanel>

Answer 1

The second parameter of the DelegateCommand constructor is a Func that tells if the Command is executable. WPF uses this to determine if buttons, etc should be enabled.

I would check your IsValid Func / method whether it works okay, that is: returns true .