Set Primary Display (ChangeDisplaySettingsEx)

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Introduction

I've seen plenty of "complicated" code for setting the "primary" display in a multiple display PC environment, but never a "simple" C# version. (This code is based off plenty of samples I've seen on the web.)

Background

This code originated out of the need to pop applications to multiple monitors during an automated start-up script (i.e., set a designated monitor as primary, start apps, then revert back to original monitor).

Using the code

The code is left raw for addition of "bells and whistles".

//manual gather - NewPrimary name ----------------------------------
WinApi.DISPLAY_DEVICE ddOne = new WinApi.DISPLAY_DEVICE();

ddOne.cb = Marshal.SizeOf(ddOne);
deviceID = 1;
WinApi.User_32.EnumDisplayDevices(null, deviceID, ref ddOne, 0);
string NewPrimary = ddOne.DeviceName;

WinApi.DEVMODE ndm6 = NewDevMode();
result = (WinApi.DisplaySetting_Results)WinApi.User_32.ChangeDisplaySettingsEx(NewPrimary, 
          ref ndm6, (IntPtr)null, (int)WinApi.DeviceFlags.CDS_SET_PRIMARY | 
          (int)WinApi.DeviceFlags.CDS_UPDATEREGISTRY, IntPtr.Zero);
Console.WriteLine("Action 3.2 result:" + result.ToString());

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)