How do I ensure a form displays on the "additional" monitor in a dual monitor scenario?

Question

I have an application in which there is a form which I want to show on second screen.

Mean If application is running on screen A and when I click on menu to show Form it should display on Screen B and same with if application is running on screen B and when I click on menu to show Form it should display on Screen A.

Answer 1

You need to use the Screen class to find a screen that the original form is not on, then set the second form's Location property based on that screen's Bounds.

For example:

var myScreen = Screen.FromControl(originalForm);
var otherScreen = Screen.AllScreens.FirstOrDefault(s => !s.Equals(myScreen)) 
               ?? myScreen;
otherForm.Left = otherScreen.WorkingArea.Left + 120;
otherForm.Top = otherScreen.WorkingArea.Top + 120;

This will work for any number of screens.

Note that it is possible that the video card is configured so that Windows sees one large screen instead of two smaller ones, in which case this becomes much more difficult.