使WPF窗口可拖动，无论单击了什么元素

当然，应用以下Window 的MouseDown事件

private void Window_MouseDown(object sender, MouseButtonEventArgs e)
{
    if (e.ChangedButton == MouseButton.Left)
        this.DragMove();
}

这将允许用户在点击/拖动任何控件时拖动窗口，但吃鼠标按钮事件(e.Handled = true(的控件除外

您可以使用PreviewMouseDown而不是MouseDown，但拖动事件会吃掉Click事件，因此您的窗口将停止响应鼠标左键单击事件。如果您真的希望能够从任何控件中单击并拖动表单，那么您可能可以使用PreviewMouseDown，启动计时器开始拖动操作，如果MouseUp事件在X毫秒内触发，则取消该操作。

如果wpf表单无论在哪里单击都需要拖动，那么简单的解决方法是使用委托在windows onload事件或网格加载事件上触发DragMove((方法

private void Grid_Loaded(object sender, RoutedEventArgs 
{
      this.MouseDown += delegate{DragMove();};
}

有时，我们无法访问Window，例如，如果我们使用DevExpress，则所有可用的都是UIElement。

步骤1：添加附加属性

解决方案是：

1. 挂接MouseMove事件
2. 在视觉树上搜索，直到找到第一个父Window
3. 使用我们新发现的Window呼叫.DragMove()

代码：

using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
namespace DXApplication1.AttachedProperty
{
    public class EnableDragHelper
    {
        public static readonly DependencyProperty EnableDragProperty = DependencyProperty.RegisterAttached(
            "EnableDrag",
            typeof (bool),
            typeof (EnableDragHelper),
            new PropertyMetadata(default(bool), OnLoaded));
        private static void OnLoaded(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
        {
            var uiElement = dependencyObject as UIElement;
            if (uiElement == null || (dependencyPropertyChangedEventArgs.NewValue is bool) == false)
            {
                return;
            }
            if ((bool)dependencyPropertyChangedEventArgs.NewValue  == true)
            {
                uiElement.MouseMove += UIElementOnMouseMove;
            }
            else
            {
                uiElement.MouseMove -= UIElementOnMouseMove;
            }
        }
        private static void UIElementOnMouseMove(object sender, MouseEventArgs mouseEventArgs)
        {
            var uiElement = sender as UIElement;
            if (uiElement != null)
            {
                if (mouseEventArgs.LeftButton == MouseButtonState.Pressed)
                {
                    DependencyObject parent = uiElement;
                    int avoidInfiniteLoop = 0;
                    // Search up the visual tree to find the first parent window.
                    while ((parent is Window) == false)
                    {
                        parent = VisualTreeHelper.GetParent(parent);
                        avoidInfiniteLoop++;
                        if (avoidInfiniteLoop == 1000)
                        {
                            // Something is wrong - we could not find the parent window.
                            return;
                        }
                    }
                    var window = parent as Window;
                    window.DragMove();
                }
            }
        }
        public static void SetEnableDrag(DependencyObject element, bool value)
        {
            element.SetValue(EnableDragProperty, value);
        }
        public static bool GetEnableDrag(DependencyObject element)
        {
            return (bool)element.GetValue(EnableDragProperty);
        }
    }
}

步骤2：将附加属性添加到任何元素，使其可以拖动窗口

如果我们添加以下附加属性，用户可以通过单击特定元素来拖动整个窗口：

<Border local:EnableDragHelper.EnableDrag="True">
    <TextBlock Text="Click me to drag this entire window"/>
</Border>

---

附录A：可选高级示例

在DevExpress的这个例子中，我们用自己的灰色矩形替换了停靠窗口的标题栏，然后确保如果用户点击并拖动所述灰色矩形，窗口将正常拖动：

<dx:DXWindow x:Class="DXApplication1.MainWindow" Title="MainWindow" Height="464" Width="765" 
    xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:dxdo="http://schemas.devexpress.com/winfx/2008/xaml/docking" 
    xmlns:local="clr-namespace:DXApplication1.AttachedProperty"
    xmlns:dxdove="http://schemas.devexpress.com/winfx/2008/xaml/docking/visualelements"
    xmlns:themeKeys="http://schemas.devexpress.com/winfx/2008/xaml/docking/themekeys">
    <dxdo:DockLayoutManager FloatingMode="Desktop">
        <dxdo:DockLayoutManager.FloatGroups>
            <dxdo:FloatGroup FloatLocation="0, 0" FloatSize="179,204" MaxHeight="300" MaxWidth="400" 
                             local:TopmostFloatingGroupHelper.IsTopmostFloatingGroup="True"                             
                             >
                <dxdo:LayoutPanel ShowBorder="True" ShowMaximizeButton="False" ShowCaption="False" ShowCaptionImage="True" 
                                  ShowControlBox="True" ShowExpandButton="True" ShowInDocumentSelector="True" Caption="TradePad General" 
                                  AllowDock="False" AllowHide="False" AllowDrag="True" AllowClose="False"
                                  >
                    <Grid Margin="0">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto"/>
                            <RowDefinition Height="*"/>
                        </Grid.RowDefinitions>
                        <Border Grid.Row="0" MinHeight="15" Background="#FF515151" Margin="0 0 0 0"
                                                                  local:EnableDragHelper.EnableDrag="True">
                            <TextBlock Margin="4" Text="General" FontWeight="Bold"/>
                        </Border>
                        <TextBlock Margin="5" Grid.Row="1" Text="Hello, world!" />
                    </Grid>
                </dxdo:LayoutPanel>
            </dxdo:FloatGroup>
        </dxdo:DockLayoutManager.FloatGroups>
    </dxdo:DockLayoutManager>
</dx:DXWindow>

---

免责声明：我不隶属于DevExpress。该技术适用于任何用户元素，包括标准WPF或Telerik(另一个优秀的WPF库提供商(。

private void Window_MouseDown(object sender, MouseButtonEventArgs e)
{
if (e.ChangedButton == MouseButton.Left)
    this.DragMove();
}

在某些情况下引发异常(即，如果在窗口上您也有一个可单击的图像，当单击该图像时会打开一个消息框。当您从消息框退出时，您将收到错误(使用更安全

private void Window_MouseDown(object sender, MouseButtonEventArgs e)
{
if (Mouse.LeftButton == MouseButtonState.Pressed)
            this.DragMove();
}

所以你们确信左键在那个时刻被按下了。

正如@fjch1997已经提到的，实现一种行为很方便。在这里，核心逻辑与@loi.efy的答案相同：

public class DragMoveBehavior : Behavior<Window>
{
    protected override void OnAttached()
    {
        AssociatedObject.MouseMove += AssociatedObject_MouseMove;
    }
    protected override void OnDetaching()
    {
        AssociatedObject.MouseMove -= AssociatedObject_MouseMove;
    }
    private void AssociatedObject_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed && sender is Window window)
        {
            // In maximum window state case, window will return normal state and
            // continue moving follow cursor
            if (window.WindowState == WindowState.Maximized)
            {
                window.WindowState = WindowState.Normal;
                // 3 or any where you want to set window location after
                // return from maximum state
                Application.Current.MainWindow.Top = 3;
            }
            window.DragMove();
        }
    }
}

用法：

<Window ...
        xmlns:h="clr-namespace:A.Namespace.Of.DragMoveBehavior"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity">
    <i:Interaction.Behaviors>
        <h:DragMoveBehavior />
    </i:Interaction.Behaviors>
    ...
</Window>

这些都是必需的！

private void UiElement_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            if (this.WindowState == WindowState.Maximized) // In maximum window state case, window will return normal state and continue moving follow cursor
            {
                this.WindowState = WindowState.Normal;
                Application.Current.MainWindow.Top = 3;// 3 or any where you want to set window location affter return from maximum state
            }
            this.DragMove();
        }
    }

可以拖动&通过单击表单上的任何位置(而不仅仅是标题栏(来放置表单。如果你有一个无边界的表单，这很方便。

这篇关于CodeProject的文章展示了实现这一点的一种可能的解决方案：

http://www.codeproject.com/KB/cs/DraggableForm.aspx

基本上创建了Form类型的子代，其中处理鼠标向下、向上和移动事件。

• 鼠标放下：记住位置
• 鼠标移动：存储新位置
• 鼠标向上：将表单定位到新位置

这里有一个视频教程中解释的类似解决方案：

http://www.youtube.com/watch?v=tJlY9aX73Vs

当用户点击表单中的控件时，我不允许拖动表单。当用户点击不同的控件时会得到不同的结果。当我的表单突然开始移动时，因为我点击了列表框、按钮、标签。。。等等，这将是令人困惑的。

<Window
...
WindowStyle="None" MouseLeftButtonDown="WindowMouseLeftButtonDown"/>
<x:Code>
    <![CDATA[            
        private void WindowMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            DragMove();
        }
    ]]>
</x:Code>

对于WPF和windows窗体来说，最有用的方法，WPF示例：

    [DllImport("user32.dll")]
    public static extern IntPtr SendMessage(IntPtr hWnd, int wMsg, int wParam, int lParam);
    public static void StartDrag(Window window)
    {
        WindowInteropHelper helper = new WindowInteropHelper(window);
        SendMessage(helper.Handle, 161, 2, 0);
    }

将其添加到您的窗口样式中(我认为属性不言自明(

<Setter Property="WindowChrome.WindowChrome">
  <Setter.Value>
    <WindowChrome GlassFrameThickness="0" ResizeBorderThickness="3" CornerRadius="0" CaptionHeight="40" />
  </Setter.Value>
</Setter>