SIlverlight: Can't find Image on Canvas_问答_开发者

开发者 https://www.devze.com 2023-01-05 05:11 出处：网络

In my Canvas, I have an image object. I haven\'t set a source in it, but it has coordinates and a size. The tag is:

In my Canvas, I have an image object. I haven't set a source in it, but it has coordinates and a size. The tag is:

Here's the problem: When I move the mouse over it, I want to find it. With this code:

VisualTreeHelper.FindElementsInHostCoordinates(point, Application.Current.RootVisual)

It won't find the image unless a source is set. If no source is set, then the image isn't returned. Does anyone know why? This is causing me problems. I have some drag/drop code and I'm looking to drop something on that Image control, but I need to know when the mouse is over it.

I know there are other ways I could do it (such as placing开发者_StackOverflow something else in that location, like a grid or something and detecting that), but that's not going to work. I can think of several ways that will work, but they're far less elegant.

If I could get the above to return my image, that would definitely be ideal.

In your code you had Point point = e.GetPosition(_canvas); This gets the MousePosition co-ordinates in relation to the canvas, but your second line VisualHelper.FindElementsInHostCoordinates(point,Application.Current.RootVisual) is searching in relation to the whole page. You need to change one or the other so they in relation to the same control. I would just change to VisualHelper.FindElementsInHostCoordinates(point,_canvas)

You can add a <Border> object around the Image object.

Or you can add eventhandlers for the mouseenter and mouse leave and change the Cursor.