c# 多显示器设置主屏幕(Set primary screen for multiple monitors)
经过google加各种百度，终于找到了一个有效的解决方案，下面是两个主要类，方便后人使用
1. Win32 API， 需要添加其它内容可以到这个网站从查找对应的c#实现
public class WinApi { public const Int32 CCHDEVICENAME = 32; public const Int32 CCHFORMNAME = 32; public enum DEVMODE_SETTINGS { ENUM_CURRENT_SETTINGS = (-1), ENUM_REGISTRY_SETTINGS = (-2) } [Flags()] public enum DisplayDeviceStateFlags : int { /// <summary>The device is part of the desktop.</summary> AttachedToDesktop = 0x1, MultiDriver = 0x2, /// <summary>The device is part of the desktop.</summary> PrimaryDevice = 0x4, /// <summary>Represents a pseudo device used to mirror application drawing for remoting or other purposes.</summary> MirroringDriver = 0x8, /// <summary>The device is VGA compatible.</summary> VGACompatible = 0x10, /// <summary>The device is removable; it cannot be the primary display.</summary> Removable = 0x20, /// <summary>The device has more display modes than its output devices support.</summary> ModesPruned = 0x8000000, Remote = 0x4000000, Disconnect = 0x2000000 } public enum Display_Device_Stateflags { DISPLAY_DEVICE_ATTACHED_TO_DESKTOP = 0x1, DISPLAY_DEVICE_MIRRORING_DRIVER = 0x8, DISPLAY_DEVICE_MODESPRUNED = 0x8000000, DISPLAY_DEVICE_MULTI_DRIVER = 0x2, DISPLAY_DEVICE_PRIMARY_DEVICE = 0x4, DISPLAY_DEVICE_VGA_COMPATIBLE = 0x10 } public enum DeviceFlags { CDS_FULLSCREEN = 0x4, CDS_GLOBAL = 0x8, CDS_NORESET = 0x10000000, CDS_RESET = 0x40000000, CDS_SET_PRIMARY = 0x10, CDS_TEST = 0x2, CDS_UPDATEREGISTRY = 0x1, CDS_VIDEOPARAMETERS = 0x20, } public enum DEVMODE_Flags { DM_BITSPERPEL = 0x40000, DM_DISPLAYFLAGS = 0x200000, DM_DISPLAYFREQUENCY = 0x400000, DM_PELSHEIGHT = 0x100000, DM_PELSWIDTH = 0x80000, DM_POSITION = 0x20 } public enum DisplaySetting_Results { DISP_CHANGE_BADFLAGS = -4, DISP_CHANGE_BADMODE = -2, DISP_CHANGE_BADPARAM = -5, DISP_CHANGE_FAILED = -1, DISP_CHANGE_NOTUPDATED = -3, DISP_CHANGE_RESTART = 1, DISP_CHANGE_SUCCESSFUL = 0 } [StructLayout(LayoutKind.Sequential)] public struct POINTL { [MarshalAs(UnmanagedType.I4)] public int x; [MarshalAs(UnmanagedType.I4)] public int y; } [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public struct DEVMODE { [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string dmDeviceName; [MarshalAs(UnmanagedType.U2)] public UInt16 dmSpecVersion; [MarshalAs(UnmanagedType.U2)] public UInt16 dmDriverVersion; [MarshalAs(UnmanagedType.U2)] public UInt16 dmSize; [MarshalAs(UnmanagedType.U2)] public UInt16 dmDriverExtra; [MarshalAs(UnmanagedType.U4)] public DEVMODE_Flags dmFields; public POINTL dmPosition; [MarshalAs(UnmanagedType.U4)] public UInt32 dmDisplayOrientation; [MarshalAs(UnmanagedType.U4)] public UInt32 dmDisplayFixedOutput; [MarshalAs(UnmanagedType.I2)] public Int16 dmColor; [MarshalAs(UnmanagedType.I2)] public Int16 dmDuplex; [MarshalAs(UnmanagedType.I2)] public Int16 dmYResolution; [MarshalAs(UnmanagedType.I2)] public Int16 dmTTOption; [MarshalAs(UnmanagedType.I2)] public Int16 dmCollate; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string dmFormName; [MarshalAs(UnmanagedType.U2)] public UInt16 dmLogPixels; [MarshalAs(UnmanagedType.U4)] public UInt32 dmBitsPerPel; [MarshalAs(UnmanagedType.U4)] public UInt32 dmPelsWidth; [MarshalAs(UnmanagedType.U4)] public UInt32 dmPelsHeight; [MarshalAs(UnmanagedType.U4)] public UInt32 dmDisplayFlags; [MarshalAs(UnmanagedType.U4)] public UInt32 dmDisplayFrequency; [MarshalAs(UnmanagedType.U4)] public UInt32 dmICMMethod; [MarshalAs(UnmanagedType.U4)] public UInt32 dmICMIntent; [MarshalAs(UnmanagedType.U4)] public UInt32 dmMediaType; [MarshalAs(UnmanagedType.U4)] public UInt32 dmDitherType; [MarshalAs(UnmanagedType.U4)] public UInt32 dmReserved1; [MarshalAs(UnmanagedType.U4)] public UInt32 dmReserved2; [MarshalAs(UnmanagedType.U4)] public UInt32 dmPanningWidth; [MarshalAs(UnmanagedType.U4)] public UInt32 dmPanningHeight; } [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] public struct DISPLAY_DEVICE { [MarshalAs(UnmanagedType.U4)] public int cb; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)] public string DeviceName; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)] public string DeviceString; [MarshalAs(UnmanagedType.U4)] public DisplayDeviceStateFlags StateFlags; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)] public string DeviceID; [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)] public string DeviceKey; } public class User_32 { [DllImport("user32.dll")] public static extern int ChangeDisplaySettings(ref DEVMODE devMode, int flags); //[DllImport("user32.dll")] //public static extern int ChangeDisplaySettingsEx(ref DEVMODE devMode, int flags); [DllImport("user32.dll")] public static extern int ChangeDisplaySettingsEx(string lpszDeviceName, [In] ref DEVMODE lpDevMode, IntPtr hwnd, int dwFlags, IntPtr lParam); [DllImport("user32.dll")] public static extern bool EnumDisplayDevices(string lpDevice, int iDevNum, ref DISPLAY_DEVICE lpDisplayDevice, int dwFlags); [DllImport("user32.dll")] public static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE devMode); } }
2. 更新主屏幕类
public class ScreenHelper { public static List<Screen> GetAllScreen() { List<WinApi.DISPLAY_DEVICE> devices = new List<WinApi.DISPLAY_DEVICE>(); List<Screen> screens = new List<Screen>(); bool error = false; //Here I am listing all DisplayDevices (Monitors) for (int devId = 0; !error; devId++) { try { WinApi.DISPLAY_DEVICE device = new WinApi.DISPLAY_DEVICE(); device.cb = Marshal.SizeOf(typeof(WinApi.DISPLAY_DEVICE)); error = !WinApi.User_32.EnumDisplayDevices(null, devId, ref device, 0); if ((device.StateFlags & WinApi.DisplayDeviceStateFlags.AttachedToDesktop) == WinApi.DisplayDeviceStateFlags.AttachedToDesktop) { devices.Add(device); } } catch (Exception) { error = true; } } devices.ForEach(d => { WinApi.DEVMODE ndm = NewDevMode(); WinApi.User_32.EnumDisplaySettings(d.DeviceName, (int)WinApi.DEVMODE_SETTINGS.ENUM_REGISTRY_SETTINGS, ref ndm); screens.Add(new Screen() { DeviceMode = ndm, ScreenDevice = d, DeviceName = d.DeviceName, IsPrimary = ((d.StateFlags & WinApi.DisplayDeviceStateFlags.PrimaryDevice) == WinApi.DisplayDeviceStateFlags.PrimaryDevice), ScreenWidth = (int)ndm.dmPelsWidth, ScreenHeight = (int)ndm.dmPelsHeight, XPosition = (int)ndm.dmPosition.x, YPosition = (int)ndm.dmPosition.y }); }); return screens; } public static void SetPrimaryScreen(string deviceName) { List<Screen> screenList = GetAllScreen(); Screen primaryScreen = GetPrimaryScreen(screenList); if (primaryScreen.ScreenDevice.DeviceName == deviceName) return; Screen newPrimaryScreen = GetScreen(deviceName); SwitchPrimaryScreen(newPrimaryScreen, primaryScreen); } public static Screen GetPrimaryScreen(List<Screen> devices) { foreach (Screen d in devices) { if ((d.ScreenDevice.StateFlags & WinApi.DisplayDeviceStateFlags.PrimaryDevice) == WinApi.DisplayDeviceStateFlags.PrimaryDevice) { return d; } } return null; } public static List<Screen> GetUnPrimaryScreen(List<Screen> devices) { List<Screen> dList = new List<Screen>(); foreach (Screen d in devices) { if ((d.ScreenDevice.StateFlags & WinApi.DisplayDeviceStateFlags.PrimaryDevice) != WinApi.DisplayDeviceStateFlags.PrimaryDevice) { dList.Add(d); } } return dList; } public static Screen GetScreen(string deviceName) { List<Screen> screenList = GetAllScreen(); return screenList.Where(p => p.ScreenDevice.DeviceName == deviceName).FirstOrDefault(); } private static void SwitchPrimaryScreen(Screen newPrimary, Screen oldPrimary) { MoveOldPrimary(newPrimary, oldPrimary); MoveNewPrimary(newPrimary, oldPrimary); CommitChange(newPrimary, oldPrimary); } private static void MoveOldPrimary(Screen newPrimary, Screen oldPrimary) { WinApi.DEVMODE ndm3 = NewDevMode(); ndm3.dmFields = WinApi.DEVMODE_Flags.DM_POSITION; ndm3.dmPosition.x = (int)newPrimary.DeviceMode.dmPelsWidth; ndm3.dmPosition.y = 0; WinApi.User_32.ChangeDisplaySettingsEx(oldPrimary.ScreenDevice.DeviceName, ref ndm3, (IntPtr)null, (int)WinApi.DeviceFlags.CDS_UPDATEREGISTRY | (int)WinApi.DeviceFlags.CDS_NORESET, IntPtr.Zero); } private static void MoveNewPrimary(Screen newPrimary, Screen oldPrimary) { WinApi.DEVMODE ndm4 = NewDevMode(); ndm4.dmFields = WinApi.DEVMODE_Flags.DM_POSITION; ndm4.dmPosition.x = 0; ndm4.dmPosition.y = 0; WinApi.User_32.ChangeDisplaySettingsEx(newPrimary.ScreenDevice.DeviceName, ref ndm4, (IntPtr)null, (int)WinApi.DeviceFlags.CDS_SET_PRIMARY | (int)WinApi.DeviceFlags.CDS_UPDATEREGISTRY | (int)WinApi.DeviceFlags.CDS_NORESET, IntPtr.Zero); } private static void CommitChange(Screen newPrimary, Screen oldPrimary) { WinApi.DEVMODE ndm5 = NewDevMode(); WinApi.User_32.ChangeDisplaySettingsEx(oldPrimary.ScreenDevice.DeviceName, ref ndm5, (IntPtr)null, (int)WinApi.DeviceFlags.CDS_UPDATEREGISTRY, (IntPtr)null); WinApi.DEVMODE ndm6 = NewDevMode(); WinApi.User_32.ChangeDisplaySettingsEx(newPrimary.ScreenDevice.DeviceName, ref ndm6, (IntPtr)null, (int)WinApi.DeviceFlags.CDS_SET_PRIMARY | (int)WinApi.DeviceFlags.CDS_UPDATEREGISTRY, IntPtr.Zero); } private static WinApi.DEVMODE NewDevMode() { WinApi.DEVMODE dm = new WinApi.DEVMODE(); dm.dmDeviceName = new String(new char[31]); dm.dmFormName = new String(new char[31]); dm.dmSize = (ushort)Marshal.SizeOf(dm); return dm; } }
