这是在silverlight中完成的，而不是在WPF中，但它应该同样工作。
在控件上建立两个私用属性：

protected bool isDragging;  
private Point clickPosition;

然后在控件的建构函式中附加一些事件行程常式：

this.MouseLeftButtonDown += new MouseButtonEventHandler(Control_MouseLeftButtonDown);
this.MouseLeftButtonUp += new MouseButtonEventHandler(Control_MouseLeftButtonUp);
this.MouseMove += new MouseEventHandler(Control_MouseMove);

现在创建这些方法：

private void Control_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    isDragging = true;
    var draggableControl = sender as UserControl;
    clickPosition = e.GetPosition(this);
    draggableControl.CaptureMouse();
}

private void Control_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    isDragging = false;
    var draggable = sender as UserControl;
    draggable.ReleaseMouseCapture();
}

private void Control_MouseMove(object sender, MouseEventArgs e)
{
    var draggableControl = sender as UserControl;

    if (isDragging && draggableControl != null)
    {
        Point currentPosition = e.GetPosition(this.Parent as UIElement);

        var transform = draggableControl.RenderTransform as TranslateTransform;
        if (transform == null)
        {
            transform = new TranslateTransform();
            draggableControl.RenderTransform = transform;
        }

        transform.X = currentPosition.X - clickPosition.X;
        transform.Y = currentPosition.Y - clickPosition.Y;
    }
}

这里需要注意几点：
1.它不一定要在画布中，也可以在堆栈面板或网格中。
2.这使得整个控件可拖动，这意味着如果您单击控件中的任何位置并拖动它，将拖动整个控件。不确定这是否正是您想要的。
编辑-
详述您问题中的一些细节：实现此功能的最佳方法是创建一个从UserControl继承的类，可能称为DraggableControl，它是使用此代码构建的，然后所有可拖动控件都应扩展DraggableControl。
编辑2 -当您在这个控件中有一个datagrid时，会有一个小问题。如果您在datagrid中排序一个栏，MouseLeftButtonUp事件永远不会触发。我已经更新了程式码，所以isDragging是受保护的。我发现最好的解决方案是将这个匿名方法系结到datagrid的LostMouseCapture事件：

this.MyDataGrid.LostMouseCapture += (sender, e) => { this.isDragging = false; };

科里的回答基本正确，但缺少一个关键因素：否则，当您移动一个项目，释放鼠标按钮，然后再次单击该项目时，转换将重置为(0,0)，并且控件将跳回到其原点。
这里有一个稍微修改过的版本，对我来说很有效：

public partial class DragItem : UserControl
{
    protected Boolean isDragging;
    private Point mousePosition;
    private Double prevX, prevY;

    public DragItem()
    {
        InitializeComponent();
    }

    private void UserControl_MouseLeftButtonDown(Object sender, MouseButtonEventArgs e)
    {
        isDragging = true;
        var draggableControl = (sender as UserControl);
        mousePosition = e.GetPosition(Parent as UIElement);
        draggableControl.CaptureMouse();
    }

    private void UserControl_MouseLeftButtonUp(Object sender, MouseButtonEventArgs e)
    {
        isDragging = false;
        var draggable = (sender as UserControl);
        var transform = (draggable.RenderTransform as TranslateTransform);
        if (transform != null)
        {
            prevX = transform.X;
            prevY = transform.Y;
        }
        draggable.ReleaseMouseCapture();
    }

    private void UserControl_MouseMove(Object sender, MouseEventArgs e)
    {
        var draggableControl = (sender as UserControl);
        if (isDragging && draggableControl != null)
        {
            var currentPosition = e.GetPosition(Parent as UIElement);
            var transform = (draggableControl.RenderTransform as TranslateTransform);
            if (transform == null)
            {
                transform = new TranslateTransform();
                draggableControl.RenderTransform = transform;
            }
            transform.X = (currentPosition.X - mousePosition.X);
            transform.Y = (currentPosition.Y - mousePosition.Y);
            if (prevX > 0)
            {
                transform.X += prevX;
                transform.Y += prevY;
            }
        }
    }
}

关键是存储以前的X和Y偏移，然后使用它们来增加当前移动的偏移，以便达到正确的聚合偏移。

如果有人想尝试一个最小解决方案，这里有一个使用MouseMove事件的解决方案。

布局

<Canvas 
  Background='Beige'
  Name='canvas'>

  <Rectangle 
    Width='50'
    Height='50'
    Fill='LightPink'
    Canvas.Left='350'
    Canvas.Top='175'
    MouseMove='Rectangle_MouseMove' />

</Canvas>

后面的代码

void OnMouseMove(object sender, MouseEventArgs e)
{
  if (e.Source is Shape shape)
  {
    if (e.LeftButton == MouseButtonState.Pressed)
    {
      Point p = e.GetPosition(canvas);
      Canvas.SetLeft(shape, p.X - shape.ActualWidth / 2);
      Canvas.SetTop(shape, p.Y - shape.ActualHeight / 2);
      shape.CaptureMouse();
    }
    else
    {
      shape.ReleaseMouseCapture();
    }
  }
}

关于 Corey Sunwold 解决方案-我去掉了MouseUp和MouseDown事件，并使用MouseButtonState简化了MouseMove方法，如下所示：）我使用Canvas.SetLeft（）和Canvas.SetTop（）代替RenderTransform，因此不需要存储MouseDown事件的旧位置。

if (e.LeftButton == MouseButtonState.Pressed && draggableControl != null)
{
   //...
}

Themelis更新了最小解代码，保留抓取位置：

private Point translation;
private bool isDragging;

void OnMouseMove(object sender, MouseEventArgs e)
{
    if (e.Source is Shape shape)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            Point p = e.GetPosition(canvas);

            if (!isDragging)
            {
                translation = new Point(p.X - Canvas.GetLeft(shape), p.Y - Canvas.GetTop(shape));
                isDragging = true;
            }

            Canvas.SetLeft(shape, p.X - translation.X);
            Canvas.SetTop(shape, p.Y - translation.Y);
            shape.CaptureMouse();
        }
        else
        {
            shape.ReleaseMouseCapture();
            isDragging = false;
        }
    }
}

我遇到了一些问题与给定的解决方案，并结束了这个：

public partial class UserControlDraggable : UserControl
{
    public UserControlDraggable()
    {
        InitializeComponent();

        MouseLeftButtonDown += new MouseButtonEventHandler(Control_MouseLeftButtonDown);
        MouseLeftButtonUp += new MouseButtonEventHandler(Control_MouseLeftButtonUp);
        MouseMove += new MouseEventHandler(Control_MouseMove);
    }

    private void Control_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        _isDragging = true;
        _mouseLocationWithinMe = e.GetPosition(this);

        CaptureMouse();
    }

    private void Control_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
    {
        _isDragging = false;
        this.ReleaseMouseCapture();
    }

    private void Control_MouseMove(object sender, MouseEventArgs e)
    {
        if (_isDragging)
        {
            var mouseWithinParent = e.GetPosition(Parent as UIElement);

            Canvas.SetLeft(this, mouseWithinParent.X - _mouseLocationWithinMe.X);
            Canvas.SetTop(this, mouseWithinParent.Y - _mouseLocationWithinMe.Y);
        }
    }

    protected bool _isDragging;
    Point _mouseLocationWithinMe;
}

它基本上是Corey的例子，但利用了Hawlett的提示。它只在父容器是Canvas时才起作用。而且，它值得用一些限制来修饰，以防止用户将控件拖到它真的不应该在的地方。

此代码完美运行！

Button newBtn = new Button();
newBtn.AddHandler(Button.ClickEvent, new RoutedEventHandler(BtTable_Click));
newBtn.AddHandler(Button.PreviewMouseLeftButtonDownEvent, new MouseButtonEventHandler(BtTable_MouseLeftButtonDown));
newBtn.AddHandler(Button.PreviewMouseLeftButtonUpEvent, new MouseButtonEventHandler(BtTable_MouseLeftButtonUp));
newBtn.AddHandler(Button.PreviewMouseMoveEvent, new MouseEventHandler(BtTable_MouseMove));

按钮移动

private object movingObject;
private double firstXPos, firstYPos;
private int ButtonSize = 50;

private void BtTable_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    Button newBtn = sender as Button;
    Canvas canvas = newBtn.Parent as Canvas;

    firstXPos = e.GetPosition(newBtn).X;
    firstYPos = e.GetPosition(newBtn).Y - ButtonSize;

    movingObject = sender;

    // Put the image currently being dragged on top of the others
    int top = Canvas.GetZIndex(newBtn);
    foreach (Button child in canvas.Children)
        if (top < Canvas.GetZIndex(child))
            top = Canvas.GetZIndex(child);
    Canvas.SetZIndex(newBtn, top + 1);
    Mouse.Capture(null);
}

private void BtTable_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
    Button newBtn = sender as Button;
    Canvas canvas = newBtn.Parent as Canvas;

    movingObject = null;

    // Put the image currently being dragged on top of the others
    int top = Canvas.GetZIndex(newBtn);
    foreach (Button child in canvas.Children)
        if (top > Canvas.GetZIndex(child))
            top = Canvas.GetZIndex(child);
    Canvas.SetZIndex(newBtn, top + 1);
    Mouse.Capture(newBtn);
}

private void BtTable_MouseMove(object sender, MouseEventArgs e)
{
    if (e.LeftButton == MouseButtonState.Pressed && sender == movingObject)
    {
        Button newBtn = sender as Button;
        Canvas canvas = newBtn.Parent as Canvas;
        // Horizontal
        double newLeft = e.GetPosition(canvas).X - firstXPos - canvas.Margin.Left;
        // newLeft inside canvas right-border?
        if (newLeft > canvas.Margin.Left + canvas.ActualWidth - newBtn.ActualWidth)
            newLeft = canvas.Margin.Left + canvas.ActualWidth - newBtn.ActualWidth;
        // newLeft inside canvas left-border?
        else if (newLeft < canvas.Margin.Left)
            newLeft = canvas.Margin.Left;

        newBtn.SetValue(Canvas.LeftProperty, newLeft);

        //Vertical
        double newTop = e.GetPosition(canvas).Y - firstYPos - canvas.Margin.Top;
        // newTop inside canvas bottom-border?
        // -- Bottom --
        if (newTop > canvas.Margin.Top + canvas.ActualHeight - newBtn.ActualHeight - ButtonSize)
            newTop = canvas.Margin.Top + canvas.ActualHeight - newBtn.ActualHeight - ButtonSize;
        // newTop inside canvas top-border?
        // -- Top --
        else if (newTop < canvas.Margin.Top - ButtonSize)
            newTop = canvas.Margin.Top - ButtonSize;

        newBtn.SetValue(Canvas.TopProperty, newTop);
    }
}

• 快乐编码;）*

我为WPF和UWP商店应用程序实现了这一点。并在用户控件本身而不是使用它的控件中添加了所有代码，您可以根据需要修改它。

世界粮食计划署

public partial class DragUserControl : UserControl
{
    public DragUserControl()
    {
        InitializeComponent();
    }

    object MovingObject;
    double FirstXPos, FirstYPos;

    private void Button_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        this.MovingObject = this;
        FirstXPos = e.GetPosition(MovingObject as Control).X;
        FirstYPos = e.GetPosition(MovingObject as Control).Y;

        Canvas canvas = this.Parent as Canvas;
        if (canvas != null)
        {
            canvas.PreviewMouseMove += this.MouseMove;
        }
    }

    private void MouseMove(object sender, MouseEventArgs e)
    {
        /*
         * In this event, at first we check the mouse left button state. If it is pressed and 
         * event sender object is similar with our moving object, we can move our control with
         * some effects.
         */
        Canvas canvas = sender as Canvas;

        Point canvasPoint = e.GetPosition(canvas);
        Point objPosition = e.GetPosition((MovingObject as FrameworkElement));
        if (e.LeftButton == MouseButtonState.Pressed)
        {
            if (MovingObject != null)
            {
//This condition will take care that control should not go outside the canvas.
                    if ((e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).X - FirstXPos > 0) && (e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).X - FirstXPos < canvas.ActualWidth - (MovingObject as FrameworkElement).ActualWidth))
                    {
                        (MovingObject as FrameworkElement).SetValue(Canvas.LeftProperty, e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).X - FirstXPos);
                    }

//This condition will take care that control should not go outside the canvas.
                    if ((e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).Y - FirstYPos > 0) && (e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).Y - FirstYPos < canvas.ActualHeight - (MovingObject as FrameworkElement).ActualHeight))
                    {
                        (MovingObject as FrameworkElement).SetValue(Canvas.TopProperty, e.GetPosition((MovingObject as FrameworkElement).Parent as FrameworkElement).Y - FirstYPos);
                    }
                }
            }
        }

        private void Ellipse_PreviewMouseLeftButtonUp_1(object sender, MouseButtonEventArgs e)
        {
            MovingObject = null;
        }
    }

Button_MouseLeftButtonDown是要拖动控件的按钮的单击事件。

UWP

public sealed partial class DragUserControl : UserControl
    {
        MovingObject;
        double FirstXPos, FirstYPos;

        public DragUserControl()
        {
            InitializeComponent();
        }

       private void Ellipse_PointerPressed(object sender, PointerRoutedEventArgs e)
        {
            this.MovingObject = this;

            FirstXPos = e.GetCurrentPoint(MovingObject as Control).Position.X;
            FirstYPos = e.GetCurrentPoint(MovingObject as Control).Position.Y;

            Canvas canvas = this.Parent as Canvas;
            if (canvas != null)
            {
                canvas.PointerMoved += Canvas_PointerMoved;
            }
        }

        private void Canvas_PointerMoved(object sender, PointerRoutedEventArgs e)
        {
            if (MovingObject != null)
            {
                Canvas canvas = sender as Canvas;

                Point canvasPoint = e.GetCurrentPoint(canvas).Position;
                Point objPosition = e.GetCurrentPoint((MovingObject as FrameworkElement)).Position;
                if (e.GetCurrentPoint(MovingObject as Control).Properties.IsLeftButtonPressed) //e.Pointer.IsInContact ==true)
                {
//This condition will take care that control should not go outside the canvas
                    if ((e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.X - FirstXPos > 0) && (e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.X - FirstXPos < canvas.ActualWidth - (MovingObject as FrameworkElement).ActualWidth))
                    {
                        (MovingObject as FrameworkElement).SetValue(Canvas.LeftProperty, e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.X - FirstXPos);
                    }

//This condition will take care that control should not go outside the canvas
                    if ((e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.Y - FirstYPos > 0) && (e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.Y - FirstYPos < canvas.ActualHeight - (MovingObject as FrameworkElement).ActualHeight))
                    {
                        (MovingObject as FrameworkElement).SetValue(Canvas.TopProperty, e.GetCurrentPoint((MovingObject as FrameworkElement).Parent as FrameworkElement).Position.Y - FirstYPos);
                    }
                }
            }
        }

        private void Ellipse_PointerReleased(object sender, PointerRoutedEventArgs e)
        {
            MovingObject = null;
        }
}

Ellipse_PointerPressed是要拖动控件的椭圆的单击事件。