Question

我有Canvas我正在绘制形状。

我添加了一个矩形，可以轻松添加拖动选项：

 <Canvas>
    <Rectangle Width="100" Height="50" Canvas.Left="197" Canvas.Top="131" Fill="Red" >
        <i:Interaction.Behaviors>
            <il:MouseDragElementBehavior/>
        </i:Interaction.Behaviors>
    </Rectangle>
</Canvas>

我希望自动完成所有这些。所以，我将xaml更改为：

<ItemsControl ItemsSource="{Binding CanvasItems, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
      <ItemsControl.ItemsPanel>
          <ItemsPanelTemplate>
             <Canvas />
          </ItemsPanelTemplate>
       </ItemsControl.ItemsPanel>
</ItemsControl>

在ViewModel：

中

private ObservableCollection<Shape> m_canvasItems = new ObservableCollection<Shape>();
public ObservableCollection<Shape> CanvasItems
{
    get => m_canvasItems;
    set
    {
        m_canvasItems = value;
        OnPropertyChanged();
    }
}
public MainWindowViewModel()
{
    var newRect = new Rectangle
    {
        Width = 100,
        Height = 50,
        Fill = Brushes.Red
    };

    Canvas.SetLeft(newRect, 197);
    Canvas.SetTop(newRect, 131);

    CanvasItems.Add(newRect);
}

在同一namespace下，我也有这个课程：

public class DragBehavior : Behavior<UIElement>
{
    public Point ElementStartPosition { get; private set; }
    private Point mouseStartPosition;
    private readonly TranslateTransform transform = new TranslateTransform();

    protected override void OnAttached()
    {
        var parent = Application.Current.MainWindow;
        AssociatedObject.RenderTransform = transform;

        AssociatedObject.MouseLeftButtonDown += (sender, e) =>
        {
            ElementStartPosition = AssociatedObject.TranslatePoint(new Point(), parent);
            mouseStartPosition = e.GetPosition(parent);
            AssociatedObject.CaptureMouse();
        };

        AssociatedObject.MouseLeftButtonUp += (sender, e) => { AssociatedObject.ReleaseMouseCapture();             };

        AssociatedObject.MouseMove += (sender, e) =>
        {
            var diff = e.GetPosition(parent) - mouseStartPosition;
            if (!AssociatedObject.IsMouseCaptured) return;

            transform.X = diff.X;
            transform.Y = diff.Y;
        };
    }
}

所以现在我希望实现我在第一个xaml中所做的事情 - 使用Rectangle类从后面的代码中添加一个拖动选项到我动态创建的DragBegavior。

这件事可以实现吗？

以编程方式添加交互性以形成c＃

0 个答案: