CODEWITHSUNDEEP
c#wpfcoordinate-systems
user342552
user342552

Reputation:

WPF Get element at specific coordinates

I have Labels inside a Canvas, I need to get the label that intersects with coordinates X,Y?

Thanks!!

Upvotes: 5

Views: 7189

Answers (2)

Ed Bayiates
Ed Bayiates

Reputation: 11230

Canvas.GetLeft(element), Canvas.GetTop(element) will get you any element's position. Use ActualWidth and ActualHeight to form its complete rectangle. You can iterate through the Children of the Canvas with a foreach.

Edit: CodeNaked pointed out that elements might be set with SetRight or SetBottom so I modified the sample code:

foreach (FrameworkElement nextElement in myCanvas.Children)
{
    double left = Canvas.GetLeft(nextElement);
    double top = Canvas.GetTop(nextElement);
    double right = Canvas.GetRight(nextElement);
    double bottom = Canvas.GetBottom(nextElement);
    if (double.IsNaN(left))
    {
        if (double.IsNaN(right) == false)
            left = right - nextElement.ActualWidth;
        else
            continue;
    }
    if (double.IsNaN(top))
    {
        if (double.IsNaN(bottom) == false)
            top = bottom - nextElement.ActualHeight;
        else
            continue;
    }
    Rect eleRect = new Rect(left, top, nextElement.ActualWidth, nextElement.ActualHeight);
    if (myXY.X >= eleRect.X && myXY.Y >= eleRect.Y && myXY.X <= eleRect.Right && myXY.Y <= eleRect.Bottom)
    {
        // Add to intersects list
    }
}

Upvotes: 3

Julien Lebosquain
Julien Lebosquain

Reputation: 41253

Simply use InputHitTest on your canvas, passing the coordinate you want as parameter. Note that InputHitTest is available on every UIElement and is not specific to canvas.

Upvotes: 7

Related Questions