Question

I’m trying to drag and drop an image from one spot on the canvas to another (should be relatively simple), but can’t figure it out. The image which I want to move has the following XAML:

<Image Height="28" HorizontalAlignment="Left" Margin="842,332,0,0" Name="cityImage" Stretch="Fill" VerticalAlignment="Top" Width="42" Source="/Settlers;component/Images/city.png" MouseLeftButtonDown="cityImage_MouseLeftButtonDown" MouseMove="cityImage_MouseMove" MouseLeftButtonUp="cityImage_MouseLeftButtonUp"/>

The code is as follows:

bool isDragging = false; Point initMousePos; private void cityImage_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) {
isDragging = true;
initMousePos = e.GetPosition(theGrid); } private void cityImage_MouseMove(object sender, MouseEventArgs e) {
if (isDragging)
{
    Image image = sender as Image;
    Canvas.SetTop(image, initMousePos.X);
    Canvas.SetLeft(image, initMousePos.Y);
    image.Visibility = System.Windows.Visibility.Visible;
} }

private void cityImage_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) {
isDragging = false; }

Answer 1

What I do to accomplish what you want is to use

System.Windows.Controls.Primitives.Thumb 

as the Root of a UserControl and set the ControlTemplate to display an image (within a border but it should work without as well), something like:

<Thumb Name="myRoot" DragDelta="MyRootDragDelta">
  <Thumb.Template>
    <ControlTemplate>
      <Image ... >
      ... see below ...
      </Image>
    </ControlTemplate>
  </Thumb.Template>
</Thumb>

Also, I bind the Source of the Image to a property of the class:

<Image.Source>
  <Binding Path="ImageSource" RelativeSource=
                 {RelativeSource FindAncestor,
                  AncestorType=my:MyImageControl, AncestorLevel=1}" />
</Image.Source>

The UserControl has a named TranslateTransform (let’s say translateTransform) whose properties X and Y are to be set in the DragDelta event handler:

private void MyRootDragDelta(object sender, DragDeltaEventArgs e) 
{
  translateTransform.X += e.HorizontalChange;
  translateTransform.Y += e.VerticalChange;
}

Don’t forget to add:

public ImageSource ImageSource { get; set; }

Hope this helps. If anything’s unclear feel free to ask further.