WPF鼠标拖动元素实例

引用：yWpf 鼠标拖动元素实例 - 天马3798 - 博客园

1.Wpf中鼠标捕获和释放

//以矩形为例
//创建鼠标捕获
Mouse.Capture(rectOne);
//释放鼠标捕获
rectOne.ReleaseMouseCapture();

2.Wpf中在定位布局Canvas下获取或设置元素的位置

在指定元素的鼠标事件中例如，MouseLeftButtonDown，MouseLeftButtonUp，MouseMove获取当前鼠标相对于Canvas 的位置，以及位置操作

//获取鼠标位置
e.GetPosition(canvasOne).X
e.GetPosition(canvasOne).Y
//获取元素位置
Canvas.GetLeft(rectOne)
Canvas.GetTop(rectOne)
//设置指定元素位置等
Canvas.SetLeft(rectOne, cLeft)
Canvas.SetTop(rectOne, cTop)

3.拖动实例代码：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        //注册移动事件
        rectOne.MouseLeftButtonDown += rectOne_MouseLeftButtonDown;
        rectOne.MouseLeftButtonUp += rectOne_MouseLeftButtonUp;
        rectOne.MouseMove += rectOne_MouseMove;
    }
    bool enableMove = false;
    double spanLeft = 0;
    double spanTop = 0;
    //鼠标移动
    private void rectOne_MouseMove(object sender, MouseEventArgs e)
    {
        if (enableMove)
        {
            var cLeft = e.GetPosition(canvasOne).X - spanLeft;
            var cTop = e.GetPosition(canvasOne).Y - spanTop;
            //设置矩形的位置
            Canvas.SetLeft(rectOne, cLeft);
            Canvas.SetTop(rectOne, cTop);
        }
    }
    //鼠标松开
    private void rectOne_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        //释放鼠标捕获
        rectOne.ReleaseMouseCapture();
        enableMove = false;
        spanLeft = spanTop = 0;
    }
    //鼠标按下
    private void rectOne_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        //创建鼠标捕获
        Mouse.Capture(rectOne);
        enableMove = true;
        spanLeft = e.GetPosition(canvasOne).X - Canvas.GetLeft(rectOne);
        spanTop = e.GetPosition(canvasOne).Y - Canvas.GetTop(rectOne);
    }
}