在WPF中，可以使用MouseLeftButtonDown、MouseLeftButtonUp和MouseMove事件来实现鼠标拖拽功能的封装。以下是一个简单的示例：

public class DraggableControl : Control{private bool isDragging = false;public DraggableControl(){this.MouseLeftButtonDown += DraggableControl_MouseLeftButtonDown;this.MouseLeftButtonUp += DraggableControl_MouseLeftButtonUp;this.MouseMove += DraggableControl_MouseMove;}private void DraggableControl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e){if (e.LeftButton == MouseButtonState.Pressed){isDragging = true;this.CaptureMouse();}}private void DraggableControl_MouseLeftButtonUp(object sender, MouseButtonEventArgs e){if (isDragging){isDragging = false;this.ReleaseMouseCapture();}}private void DraggableControl_MouseMove(object sender, MouseEventArgs e){if (isDragging){Point currentPosition = e.GetPosition(this.Parent as UIElement);Canvas.SetLeft(this, currentPosition.X - (this.ActualWidth / 2));Canvas.SetTop(this, currentPosition.Y - (this.ActualHeight / 2));}}}

使用这个DraggableControl类可以方便地给任意的WPF控件添加鼠标拖拽功能。只需要在XAML文件中声明DraggableControl替代原本的控件即可。