private void MyControl_MouseMove(object sender, MouseEventArgs e) { if(sender is UIElement uIElement) { if (isDragging) { Point newPoint = e.GetPosition(canvas); double deltaX = newPoint.X - startPoint.X; double deltaY = newPoint.Y - startPoint.Y; Canvas.SetLeft(uIElement, Canvas.GetLeft(uIElement) + deltaX); Canvas.SetTop(uIElement, Canvas.GetTop(uIElement) + deltaY); startPoint = newPoint; } } } private void MyControl_MouseDown(object sender, MouseButtonEventArgs e) { if (sender is UIElement uIElement) { isDragging = true; startPoint = e.GetPosition(canvas); uIElement.CaptureMouse(); } } private void MyControl_MouseUp(object sender, MouseButtonEventArgs e) { if (sender is UIElement uIElement) { isDragging = false; uIElement.ReleaseMouseCapture(); } }令移动的控件不超过Canvas的边界

要确保移动的控件不超过Canvas的边界，可以在MyControl_MouseMove方法中添加一些额外的代码来检查控件的位置是否在Canvas的范围内。可以使用Canvas.GetLeft和Canvas.GetTop方法获取控件的左上角位置，然后检查该位置是否在Canvas的范围内。如果位置超出边界，则可以将控件的位置调整为最接近边界的位置。以下是修改后的代码：

private void MyControl_MouseMove(object sender, MouseEventArgs e)
{
    if (sender is UIElement uIElement)
    {
        if (isDragging)
        {
            Point newPoint = e.GetPosition(canvas);
            double deltaX = newPoint.X - startPoint.X;
            double deltaY = newPoint.Y - startPoint.Y;

            double newLeft = Canvas.GetLeft(uIElement) + deltaX;
            double newTop = Canvas.GetTop(uIElement) + deltaY;

            // Check if the new position is within the canvas bounds
            if (newLeft < 0)
            {
                newLeft = 0;
            }
            else if (newLeft + uIElement.ActualWidth > canvas.ActualWidth)
            {
                newLeft = canvas.ActualWidth - uIElement.ActualWidth;
            }

            if (newTop < 0)
            {
                newTop = 0;
            }
            else if (newTop + uIElement.ActualHeight > canvas.ActualHeight)
            {
                newTop = canvas.ActualHeight - uIElement.ActualHeight;
            }

            Canvas.SetLeft(uIElement, newLeft);
            Canvas.SetTop(uIElement, newTop);

            startPoint = newPoint;
        }
    }
}

在这个修改后的版本中，我们首先计算出控件的新位置，然后检查它是否在Canvas的范围内。如果控件的位置超过了Canvas的边界，则将其调整为最接近的边界位置。这样，就可以确保移动的控件不会超出Canvas的范围。