How do I ensure a form displays on the “additional

Question

This question already has an answer here:

• Showing a Windows form on a secondary monitor? 8 answers

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

I used this for an XNA 4 Dual Screen Application (Full Screen XNA Game Window + WinForm)

In the Form_Load() method, place the following code:

var primaryDisplay = Screen.AllScreens.ElementAtOrDefault(0);  
var extendedDisplay = Screen.AllScreens.FirstOrDefault(s => s != primaryDisplay) ?? primaryDisplay;

this.Left = extendedDisplay.WorkingArea.Left + (extendedDisplay.Bounds.Size.Width / 2) - (this.Size.Width / 2);
this.Top = extendedDisplay.WorkingArea.Top + (extendedDisplay.Bounds.Size.Height / 2) - (this.Size.Height / 2);

Answer 2

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.

Answer 3

On the OnLoad method change the Location of the window.

protected void Form1_OnLoad(...) {
    showOnMonitor(1);
}

private void showOnMonitor(int showOnMonitor) 
{ 
    Screen[] sc; 
    sc = Screen.AllScreens; 
    if (showOnMonitor >= sc.Length) {
        showOnMonitor = 0;
    }

    this.StartPosition = FormStartPosition.Manual; 
    this.Location = new Point(sc[showOnMonitor].Bounds.Left, sc[showOnMonitor].Bounds.Top);
    // If you intend the form to be maximized, change it to normal then maximized.
    this.WindowState = FormWindowState.Normal;
    this.WindowState = FormWindowState.Maximized;
}

Answer 4

Below is a function allowing you to display a form on any monitor. For your current scenario you can call this showOnMonitor(1);.

Essentially you have to get screen information from Screen.AllScreens and then get the dimensions of each, then place your form where you need it

function void showOnMonitor(int showOnMonitor) 
{ 
    Screen[] sc; 
    sc = Screen.AllScreens; 

    Form2 f = new Form2(); 

    f.FormBorderStyle = FormBorderStyle.None; 
    f.Left = sc[showOnMonitor].Bounds.Left; 
    f.Top = sc[showOnMonitor].Bounds.Top; 
    f.StartPosition = FormStartPosition.Manual; 

    f.Show(); 
}

Note don't forget to do validation to ensure you actually have two screens etc else an exception will be thrown for accessing sc[showOnMonitor]