WPF实现组件拖动（Grid）

xaml：

<Window x:Class="WpfApp3Test.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"
mc:Ignorable="d"
Title="MainWindow"
Height="600" Width="800"
WindowStartupLocation="CenterScreen">

<Window.Resources>
<Style x:Key="BorderStyle" TargetType="Border">
<Setter Property="Height" Value="30"/>
<Setter Property="Background" Value="YellowGreen"/>
</Style>

<Style x:Key="TextBlockStyle" TargetType="TextBlock">
<Setter Property="Foreground" Value="Yellow"/>
<Setter Property="FontSize" Value="20"/>
</Style>
</Window.Resources>

<Grid x:Name="parentGrid">

<!-- 组件A -->
<Canvas x:Name="ComponentA" MouseLeftButtonDown="A_MouseLeftButtonDown">
<Rectangle Width="500" Height="300" Fill="LightBlue" />
<TextBlock Canvas.Left="20" Canvas.Top="20" Text="组件A（Canvas）" FontSize="16" />
</Canvas>

<!-- 组件B 使用 Margin 进行定位 -->
<Border x:Name="ComponentB"
Width="300" Height="250"
BorderBrush="Black" BorderThickness="1"
HorizontalAlignment="Left" VerticalAlignment="Top">
<!-- 用 Margin 替代 Canvas.Left/Top -->
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="30" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>

<Border x:Name="TitleBar"
Grid.Row="0"
Style="{StaticResource BorderStyle}"
MouseLeftButtonDown="B_TitleBar_MouseLeftButtonDown"
MouseMove="B_TitleBar_MouseMove">
<TextBlock Text="B的标题栏" Style="{StaticResource TextBlockStyle}"
VerticalAlignment="Center" Margin="5" />
</Border>

<ScrollViewer Grid.Row="1"
VerticalScrollBarVisibility="Auto"
IsHitTestVisible="False">
<ItemsControl x:Name="ContentItems">
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding}" Margin="5" FontSize="14" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
</Grid>
</Border>
</Grid>
</Window>

xaml.cs：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Media.Media3D;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp3Test
{
/// <summary>
///
/// /// MainWindow.xaml 的交互逻辑
/// /// </summary>
public partial class MainWindow : Window
{
private bool _isDragging = false;
private Point _startMousePosition;
private Thickness _startMargin;

public MainWindow()
{
InitializeComponent();
ContentItems.ItemsSource = new List<string> { "项1", "项2", "项3" };
}

private void A_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
MessageBox.Show("点击了组件A");
}

private void B_TitleBar_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
if (!_isDragging)
{
_isDragging = true;
_startMousePosition = e.GetPosition(parentGrid); // 基于 Grid
_startMargin = ComponentB.Margin;
TitleBar.CaptureMouse();
}
else
{
_isDragging = false;
TitleBar.ReleaseMouseCapture();
}

e.Handled = true; // 防止事件冒泡
}

private void B_TitleBar_MouseMove(object sender, MouseEventArgs e)
{
if (_isDragging && TitleBar.IsMouseCaptured)
{
Point currentMousePos = e.GetPosition(parentGrid);

double offsetX = currentMousePos.X - _startMousePosition.X;
double offsetY = currentMousePos.Y - _startMousePosition.Y;

ComponentB.Margin = new Thickness(
_startMargin.Left + offsetX,
_startMargin.Top + offsetY,
0, 0);

}
}
}

}