Get Absolute Position of element within the window in wpf

问题

I would like to get the absolute position of an element in relation to the window/root element when it is double clicked. The element\'s relative position within it\'s parent is all I can seem to get to, and what I\'m trying to get to is the point relative to the window. I\'ve seen solutions of how to get a the point of an element on the screen, but not in the window.

回答1:

I think what BrandonS wants is not the position of the mouse relative to the root element, but rather the position of some descendant element.

For that, there is the TransformToAncestor method:

Point relativePoint = myVisual.TransformToAncestor(rootVisual)
                              .Transform(new Point(0, 0));

Where myVisual is the element that was just double-clicked, and rootVisual is Application.Current.MainWindow or whatever you want the position relative to.

回答2:

To get the absolute position of an UI element within the window you can use:

Point position = desiredElement.PointToScreen(new Point(0d, 0d));

If you are within an User Control, and simply want relative position of the UI element within that control, simply use:

Point position = desiredElement.PointToScreen(new Point(0d, 0d)),
controlPosition = this.PointToScreen(new Point(0d, 0d));

position.X -= controlPosition.X;
position.Y -= controlPosition.Y;

回答3:

Add this method to a static class:

 public static Rect GetAbsolutePlacement(this FrameworkElement element, bool relativeToScreen = false)
    {
        var absolutePos = element.PointToScreen(new System.Windows.Point(0, 0));
        if (relativeToScreen)
        {
            return new Rect(absolutePos.X, absolutePos.Y, element.ActualWidth, element.ActualHeight);
        }
        var posMW = Application.Current.MainWindow.PointToScreen(new System.Windows.Point(0, 0));
        absolutePos = new System.Windows.Point(absolutePos.X - posMW.X, absolutePos.Y - posMW.Y);
        return new Rect(absolutePos.X, absolutePos.Y, element.ActualWidth, element.ActualHeight);
    }

Set relativeToScreen paramater to true for placement from top left corner of whole screen or to false for placement from top left corner of application window.

回答4:

I know that this question is old, but, since .NET 3.0, you can simply use *yourElement*.TranslatePoint(new Point(0, 0), *theContainerOfYourChoice*).

This will give you the point 0, 0 of your button, but towards the container. (You can also give an other point that 0, 0)

Check here for the doc.

回答5:

Hm. You have to specify window you clicked in Mouse.GetPosition(IInputElement relativeTo) Following code works well for me

protected override void OnMouseDown(MouseButtonEventArgs e)
    {
        base.OnMouseDown(e);
        Point p = e.GetPosition(this);
    }

I suspect that you need to refer to the window not from it own class but from other point of the application. In this case Application.Current.MainWindow will help you.

来源：https://stackoverflow.com/questions/386731/get-absolute-position-of-element-within-the-window-in-wpf

标签

wpf

wpf-positioning