WPF中拖动控件,实现位置随意摆放

来源：互联网发布：数控编程代码z代表什么编辑：程序博客网时间：2024/04/30 11:43

在WPF中,除了可以通过处理鼠标事件来实现控件位置的拖动以外,还可以通过定义一些控件的行为,来实现控件的拖动,具体操作步骤如下:

自定义实现拖动的类库

1. 使用VS2010建立一个C#的类库

2. 增加"System.Windows.Interactivity.dll"库的引用\

如果使用的是Blend4,则位置为:"C:\Program Files\Microsoft SDKs\Expression\Blend\.NETFramework\v4.0\Libraries"

如果使用的是Blend3,则位置为:"C:\Program Files\Microsoft SDKs\Expression\Blend 3\Interactivity\Libraries\WPF"

3. 向项目中添加一个新的类文件.并命名为"DrapControlLibrary.cs",该文件的源码如下

[csharp] view plaincopy
using System;  
using System.Net;  
using System.Windows;  
using System.Windows.Controls;  
using System.Windows.Documents;  
using System.Windows.Ink;  
using System.Windows.Input;  
using System.Windows.Media;  
using System.Windows.Media.Animation;  
using System.Windows.Shapes;  
using System.Windows.Interactivity;  
  
namespace DrapControlLibrary  
{  
    public class DragInCanvasBehavior : Behavior<UIElement>  
    {  
        private Canvas canvas;  
  
        protected override void OnAttached()  
        {  
            base.OnAttached();  
  
            // Hook up event handlers.              
            this.AssociatedObject.MouseLeftButtonDown += AssociatedObject_MouseLeftButtonDown;  
            this.AssociatedObject.MouseMove += AssociatedObject_MouseMove;  
            this.AssociatedObject.MouseLeftButtonUp += AssociatedObject_MouseLeftButtonUp;  
        }  
  
        protected override void OnDetaching()  
        {  
            base.OnDetaching();  
  
            // Detach event handlers.  
            this.AssociatedObject.MouseLeftButtonDown -= AssociatedObject_MouseLeftButtonDown;  
            this.AssociatedObject.MouseMove -= AssociatedObject_MouseMove;  
            this.AssociatedObject.MouseLeftButtonUp -= AssociatedObject_MouseLeftButtonUp;  
        }  
  
        // Keep track of when the element is being dragged.  
        private bool isDragging = false;  
  
        // When the element is clicked, record the exact position  
        // where the click is made.  
        private Point mouseOffset;  
  
        private void AssociatedObject_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)  
        {  
            // Find the canvas.  
            if (canvas == null) canvas = VisualTreeHelper.GetParent(this.AssociatedObject) as Canvas;  
  
            // Dragging mode begins.  
            isDragging = true;  
  
            // Get the position of the click relative to the element  
            // (so the top-left corner of the element is (0,0).  
            mouseOffset = e.GetPosition(AssociatedObject);  
  
            // Capture the mouse. This way you'll keep receiveing  
            // the MouseMove event even if the user jerks the mouse  
            // off the element.  
            AssociatedObject.CaptureMouse();  
        }  
  
        private void AssociatedObject_MouseMove(object sender, MouseEventArgs e)  
        {  
            if (isDragging)  
            {  
                // Get the position of the element relative to the Canvas.  
                Point point = e.GetPosition(canvas);  
  
                // Move the element.  
                AssociatedObject.SetValue(Canvas.TopProperty, point.Y - mouseOffset.Y);  
                AssociatedObject.SetValue(Canvas.LeftProperty, point.X - mouseOffset.X);  
            }  
        }  
  
        private void AssociatedObject_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)  
        {  
            if (isDragging)  
            {  
                AssociatedObject.ReleaseMouseCapture();  
                isDragging = false;  
            }  
        }  
    }  
}  

4. 编译生成类库文件,类库文件名称为"DrapControlLibrary.dll"

制作测试程序

1. 使用Blend4新建一个WPF程序

2. 修改主XAML文件,修改后的结果如下

[html] view plaincopy
<Window  
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
    xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"   
        xmlns:custom="clr-namespace:DrapControlLibrary;assembly=DrapControlLibrary" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"  
    x:Class="DrapControlTest.MainWindow"  
    x:Name="Window"  
    Title="DrapControlTest"  
    Width="300" Height="250" ResizeMode="CanMinimize" Background="White">  
  
    <Canvas>  
        <TreeView Canvas.Left="10" Canvas.Top="80" Width="200" Height="50">  
            <i:Interaction.Behaviors>  
                <custom:DragInCanvasBehavior/>  
            </i:Interaction.Behaviors>  
        </TreeView>  
        <ListView Canvas.Left="10" Canvas.Top="15" Width="200" Height="50">  
            <i:Interaction.Behaviors>  
                <custom:DragInCanvasBehavior/>  
            </i:Interaction.Behaviors>  
        </ListView>   
        <Rectangle Canvas.Left="10" Canvas.Top="10" Fill="Yellow" Width="40" Height="60"/>  
        <Ellipse Canvas.Left="10" Canvas.Top="70" Fill="Blue" Width="80" Height="60">  
            <i:Interaction.Behaviors>  
                <custom:DragInCanvasBehavior/>  
            </i:Interaction.Behaviors>  
        </Ellipse>  
        <Ellipse Canvas.Left="80" Canvas.Top="70" Fill="OrangeRed" Width="40" Height="70">  
            <i:Interaction.Behaviors>  
                <custom:DragInCanvasBehavior/>  
            </i:Interaction.Behaviors>  
        </Ellipse>  
    </Canvas>  
</Window>  

3. 编译文件,能够看到效果了吧?是不是很帅

转自：http://blog.csdn.net/wangyong0921/article/details/7003338