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.

Are you **sure**? What happens when one of your users buys a third monitor? What happens if the app is used over Remote Desktop? — SLaks, Apr 01 '10 at 14:36
This question (and the accepted answer) are more specific and therefore not an exact duplicate of http://stackoverflow.com/questions/1363374/showing-a-windows-form-on-a-secondary-monitor . Both questions are complementary. — Stéphane Gourichon, Feb 03 '15 at 05:56

score 43 · Accepted Answer · edited May 11 '15 at 20:31

43

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.

edited May 11 '15 at 20:31

Jason

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answered Apr 01 '10 at 14:32

SLaks

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if the originator form is not available?? – Mohsan Apr 01 '10 at 15:13
I have two screens set as "extended" on my Windows7. If I use your code my window remain on first screen because otherScreen.WorkingArea is always placed on (0,0); I had to use otherScreen.Bounds to move windows on top-left of second screen. Am I correct? – Marco Feb 01 '13 at 13:43
2

More: _(s => s != myScreen)_ is not working; I had to use _(s => !s.Equals(myScreen))_ – Marco Feb 01 '13 at 13:45
Good answer! In a short code it provides exactly what is asked for, and even a safe fallback to using the same screen if only one is available, plus a hint on how to position the Form relative to that screen. Notice that `WorkingArea` is the area where the form would be viewable (not hidden by e.g. the task bar), and it is equal to `Bounds` when there are no bars or borders (like the task bar). Notice that the task bar may actually be on the secondary screen. – Stéphane Gourichon Feb 03 '15 at 05:51
1

I had to set `otherForm.StartPosition = FormStartPosition.Manual` for this to work. – Jeff B Jun 22 '15 at 18:13
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You should use the `Bounds` property, as stated by @Marco – JwJosefy Jul 01 '16 at 02:06

Chris · Answer 2 · 2013-02-01T14:26:22.920

21

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]

edited Feb 01 '13 at 14:26

answered Apr 01 '10 at 14:32

Chris

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This still does not completely answer the question. – SLaks Apr 01 '10 at 14:33
2

It should be f.Left = sc[showOnMonitor].Bounds.Left; f.Top = sc[showOnMonitor].Bounds.Top; – Wildhorn Aug 05 '10 at 18:50

score 12 · Answer 3 · answered Nov 18 '11 at 05:28

12

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;
}

answered Nov 18 '11 at 05:28

Nap

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Why not just `this.Location = sc[showOnMonitor].Bounds.Location`? – Endy Tjahjono Mar 06 '12 at 09:31
Yes you can do that too. – Nap Mar 06 '12 at 12:01
@Nap, Does your code work if i connect the second monitor via hdmi port? – M_Mogharrabi Jul 21 '14 at 06:41
@M_Mogharrabi I was able to test with vga and hdmi ports. – Nap Jan 08 '19 at 08:41

Eric · Answer 4 · 2013-10-20T06:48:54.390

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);

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

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