C# WPF 控件移动代码

前台代码，在窗体里加入了一个Button控件

<Window x:Class="DragMove.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:DragMove"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid Name="grid">
        <Button Name="button"   
                Content="Drag Move This Button"
                Height="30"
                Width="160"/>
        <Grid Width="50" Height="150">
            <Canvas x:Name="canvas"
                Height="50"
                Width="50"
                Background="Red"
                MouseDown="c_MouseDown"
                MouseMove="c_MouseMove"
                MouseUp="c_MouseUp">
                <TextBlock Text="123456"/>
            </Canvas>
        </Grid>
       
    </Grid>
</Window>

后台代码

namespace DragMove
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            // Button控件在捕获了MouseLeftButtonDown事件后，会将该事件的“Handled”设置为true;
            // 这个属性是用在事件路由中的，当某个控件得到一个RoutedEvent，就会检测Handled是否为true，为true则忽略该事件;
            // 由于Button控件本身的Click事件，相当于将MouseLeftButtonDown事件抑制（Supress)掉了，转换成了Click事件;
            // 所以，如果一定要使用这个事件的话，需要在初始化的函数里利用UIElement的AddHandler方法，显式的增加这个事件;
            button.AddHandler(Button.MouseLeftButtonDownEvent, new MouseButtonEventHandler(this.Button_MouseLeftButtonDown), true);
            button.AddHandler(Button.MouseLeftButtonUpEvent, new MouseButtonEventHandler(this.Button_MouseLeftButtonUp), true);
            button.AddHandler(Button.MouseMoveEvent, new MouseEventHandler(this.Button_MouseMove), true);
        }
        #region button 移动代码
        private void Button_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                Button tmp = (Button)sender;
                double dx = e.GetPosition(null).X - pos.X + tmp.Margin.Left;
                double dy = e.GetPosition(null).Y - pos.Y + tmp.Margin.Top;
                tmp.Margin = new Thickness(dx, dy, 0, 0);
                pos = e.GetPosition(tmp);
            }
        }
        Point pos = new Point();
        private void Button_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            Button tmp = (Button)sender;
            pos = e.GetPosition(this.button);
            this.button.CaptureMouse();
            this.button.Cursor = Cursors.Hand;
        }
        private void Button_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            Button tmp = (Button)sender;
            tmp.ReleaseMouseCapture();
        }
        #endregion
        #region canvas移动代码
        Point mousePoint = new Point();
        private void c_MouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                mousePoint = e.GetPosition(this.canvas);
                canvas.CaptureMouse();
                canvas.Cursor = Cursors.Hand;
            }
        }
        private void c_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                Canvas tmp = (Canvas)sender;
                double dx = e.GetPosition(this.canvas).X - mousePoint.X + tmp.Margin.Left;
                double dy = e.GetPosition(this.canvas).Y - mousePoint.Y + tmp.Margin.Top;
                tmp.Margin = new Thickness(0, dy, 0, 0);
                mousePoint = e.GetPosition(tmp);
            }
        }
        private void c_MouseUp(object sender, MouseButtonEventArgs e)
        {
            this.canvas.ReleaseMouseCapture();
        }
        #endregion
    }
}