Centering a child window of WinForms when parent is of WPF

Question

I know setting up child window property for displaying in WinForms and WPF. This can be done by setting up the parent / owner depending on WinForm/ WPF.

But recently, I came across a situation where I need to setup the child window to center of parent, where Child is of WinForms and parent is of WPF.

I tried with,

newForm window = new newForm;
window.Owner = this;

Which would obviously won't work, and

window.StartPosition = FormStartPosition.CenterParent;

after,

newForm window = new newForm;
window.MdiParent = this;

Also, won't work.

Any suggestions on how can I possibly achieve this?

Answer 1

I don't think there is a built in way to do what you want, but calculating the value isn't overly difficult. Here is a simple calculation that sets the center of the child equal to the center of the parent.

var form = new Form();
//This calculates the relative center of the parent, 
//then converts the resulting point to screen coordinates.
var relativeCenterParent = new Point(ActualWidth / 2, ActualHeight / 2);
var centerParent = this.PointToScreen(relativeCenterParent);
//This calculates the relative center of the child form.
var hCenterChild = form.Width / 2;
var vCenterChild = form.Height / 2;
//Now we create a new System.Drawing.Point for the desired location of the
//child form, subtracting the childs center, so that we end up with the child's 
//center lining up with the parent's center.
//(Don't get System.Drawing.Point (Windows Forms) confused with System.Windows.Point (WPF).)
var childLocation = new System.Drawing.Point(
    (int)centerParent.X - hCenterChild,
    (int)centerParent.Y - vCenterChild);
//Set the new location.
form.Location = childLocation;

//Set the start position to Manual, otherwise the location will be overwritten
//by the start position calculation.
form.StartPosition = FormStartPosition.Manual;

form.ShowDialog();

Note: It does not include the window chrome for either the parent or the child, so it may be slightly off center vertically.