WPF按钮按下/释放绑定

Question

I am new to WPF and trying to do my best to follow the MVVM button Im struggling with a current problem I have a view Model class

public class MainViewModel
{
    private bool _Reset;
    public bool Reset{ get{ return _Reset;} set {_Reset = value;} }
    ...
}

Now I want to bind a button so that if while Im pressing it _Reset is true and when I release it _Reset is false I feel like the command pattern is alot of work for a simple on/off

Is there a way to bind the IsPressed of a button to a property from my data context

I want to do this as simple as possible because I have a dozen or so buttons all doing the type of thing just other properties

Answer 1

So what you are going to need to do is import System.Windows.Interactivity . Go to references, add reference, Assemblies, Extensions. You will find it there. Next add it to your project

xmlns:inter="http://schemas.microsoft.com/expression/2010/interactivity"

you can now use the PreviewMouseLeftButtonDown and PreviewMouseLeftButtonUp event.

<Button Content="Some Button">
        <inter:Interaction.Triggers>
            <inter:EventTrigger EventName="PreviewMouseLeftButtonDown">
                <inter:InvokeCommandAction Command="{Binding ButtonDown}"/>
            </inter:EventTrigger>
            <inter:EventTrigger EventName="PreviewMouseLeftButtonUp">
                <inter:InvokeCommandAction Command="{Binding ButtonUp}"/>
            </inter:EventTrigger>
        </inter:Interaction.Triggers>
    </Button>

 public class MainViewModel : ViewModelBase
{
    public MainViewModel()
    {
        ButtonDown = new RelayCommand(OnButtonDown);
        ButtonUp = new RelayCommand(OnButtonUp);
    }
    public RelayCommand ButtonDown { get; set; }
    public RelayCommand ButtonUp { get; set; }

    private void OnButtonUp()
    {
        Debug.WriteLine("Button Released");
    }

    private void OnButtonDown()
    {
        Debug.WriteLine("Button Pressed");
    }
}