For example, my computer has two monitors, the primary monitor's resolution is 800*600, the other monitor's resolution is 1600*900.
I would like define the resolution on one monitor only ?
The function 'SetDisplayConfig' change the resolution screen on the two minotors...
https://learn.microsoft.com/fr-fr/windows-hardware/drivers/display/ccd-apis https://learn.microsoft.com/fr-fr/windows/win32/api/winuser/nf-winuser-setdisplayconfig
[DllImport("User32.dll")]
public static extern int SetDisplayConfig(
uint numPathArrayElements,
[In] DisplayConfigPathInfo[] pathArray,
uint numModeInfoArrayElements,
[In] DisplayConfigModeInfo[] modeInfoArray,
SdcFlags flags
);
private static Boolean SetDisplaySettings(int Id_Monitor, uint Width, uint Height, uint Scaling)
{
try
{
CCDWrapper.DisplayConfigPathInfo[] pathInfoArray = new CCDWrapper.DisplayConfigPathInfo[0] { };
CCDWrapper.DisplayConfigModeInfo[] modeInfoArray = new CCDWrapper.DisplayConfigModeInfo[0] { };
CCDWrapper.MonitorAdditionalInfo[] additionalInfo = new CCDWrapper.MonitorAdditionalInfo[0] { };
bool Status = GetDisplaySettings(ref pathInfoArray, ref modeInfoArray, ref additionalInfo, true);
CCDWrapper.DisplayConfigPathInfo[] pathInfoArrayCurrent = new CCDWrapper.DisplayConfigPathInfo[0] { };
CCDWrapper.DisplayConfigModeInfo[] modeInfoArrayCurrent = new CCDWrapper.DisplayConfigModeInfo[0] { };
CCDWrapper.MonitorAdditionalInfo[] additionalInfoCurrent = new CCDWrapper.MonitorAdditionalInfo[0] { };
bool StatusCurrent = GetDisplaySettings(ref pathInfoArrayCurrent, ref modeInfoArrayCurrent, ref additionalInfoCurrent, false);
if (StatusCurrent)
{
for (int iPathInfo = 0; iPathInfo <= pathInfoArray.Length-1; iPathInfo++)
//for (int iPathInfo = 0; iPathInfo <= pathInfoArray.Length - 1; iPathInfo++)
{
for (int iPathInfoCurrent = 0; iPathInfoCurrent <= pathInfoArrayCurrent.Length - 1; iPathInfoCurrent++)
{
if ((pathInfoArray[iPathInfo].sourceInfo.id == pathInfoArrayCurrent[iPathInfoCurrent].sourceInfo.id) && (pathInfoArray[iPathInfo].targetInfo.id == pathInfoArrayCurrent[iPathInfoCurrent].targetInfo.id))
{
pathInfoArray[iPathInfo].sourceInfo.adapterId.LowPart = pathInfoArrayCurrent[iPathInfoCurrent].sourceInfo.adapterId.LowPart;
pathInfoArray[iPathInfo].targetInfo.adapterId.LowPart = pathInfoArrayCurrent[iPathInfoCurrent].targetInfo.adapterId.LowPart;
pathInfoArray[iPathInfo].targetInfo.scaling = (CCDWrapper.DisplayConfigScaling)Scaling;
break;
}
}
}
for (int iModeInfo = 0; iModeInfo <= modeInfoArray.Length - 1; iModeInfo++)
{
for (int iPathInfo = 0; iPathInfo <= pathInfoArray.Length - 1; iPathInfo++)
{
if ((modeInfoArray[iModeInfo].id == pathInfoArray[iPathInfo].targetInfo.id) && (modeInfoArray[iModeInfo].infoType == CCDWrapper.DisplayConfigModeInfoType.Target))
{
for (int iModeInfoSource = 0; iModeInfoSource <= modeInfoArray.Length - 1; iModeInfoSource++)
{
if ((modeInfoArray[iModeInfoSource].id == pathInfoArray[iPathInfo].sourceInfo.id) && (modeInfoArray[iModeInfoSource].adapterId.LowPart == modeInfoArray[iModeInfo].adapterId.LowPart) && (modeInfoArray[iModeInfoSource].infoType == CCDWrapper.DisplayConfigModeInfoType.Source))
{
modeInfoArray[iModeInfoSource].adapterId.LowPart = pathInfoArray[iPathInfo].sourceInfo.adapterId.LowPart;
modeInfoArray[iModeInfoSource].sourceMode.height = Height;
modeInfoArray[iModeInfoSource].sourceMode.width = Width;
break;
}
}
modeInfoArray[iModeInfo].adapterId.LowPart = pathInfoArray[iPathInfo].targetInfo.adapterId.LowPart;
break;
}
}
}
uint numPathArrayElements = System.Convert.ToUInt32(pathInfoArray.Length);
uint numModeInfoArrayElements = System.Convert.ToUInt32(modeInfoArray.Length);
long Result = CCDWrapper.SetDisplayConfig(numPathArrayElements, pathInfoArray, numModeInfoArrayElements, modeInfoArray, CCDWrapper.SdcFlags.Apply | CCDWrapper.SdcFlags.UseSuppliedDisplayConfig | CCDWrapper.SdcFlags.SaveToDatabase | CCDWrapper.SdcFlags.NoOptimization | CCDWrapper.SdcFlags.AllowChanges);
if (Result == 0)
return true;
else
return false;
}
else
return false;
}
catch (Exception ex)
{
EventLog.WriteEntry("ResolutionEcran", "Erreur SetDisplaySettings : " + ex.Message, EventLogEntryType.Error);
return false;
}
}
private static Boolean GetDisplaySettings(ref CCDWrapper.DisplayConfigPathInfo[] pathInfoArray, ref CCDWrapper.DisplayConfigModeInfo[] modeInfoArray, ref CCDWrapper.MonitorAdditionalInfo[] additionalInfo, Boolean ActiveOnly, [System.Runtime.InteropServices.Optional] int ID_Monitor)
{
uint numPathArrayElements;
uint numModeInfoArrayElements;
CCDWrapper.QueryDisplayFlags queryFlags = CCDWrapper.QueryDisplayFlags.AllPaths;
if (ActiveOnly)
{
//queryFlags = CCDWrapper.QueryDisplayFlags.OnlyActivePaths;
queryFlags = CCDWrapper.QueryDisplayFlags.OnlyActivePaths;
}
var status = CCDWrapper.GetDisplayConfigBufferSizes(queryFlags, out numPathArrayElements, out numModeInfoArrayElements);
if (status == 0)
{
pathInfoArray = new CCDWrapper.DisplayConfigPathInfo[numPathArrayElements];
modeInfoArray = new CCDWrapper.DisplayConfigModeInfo[numModeInfoArrayElements];
additionalInfo = new CCDWrapper.MonitorAdditionalInfo[numModeInfoArrayElements];
status = CCDWrapper.QueryDisplayConfig(queryFlags, ref numPathArrayElements, pathInfoArray, ref numModeInfoArrayElements, modeInfoArray, IntPtr.Zero);
if (status == 0)
{
for (var iMode = 0; iMode < numModeInfoArrayElements; iMode++)
{
if (modeInfoArray[iMode].infoType == CCDWrapper.DisplayConfigModeInfoType.Target)
{
try
{
additionalInfo[iMode] = CCDWrapper.GetMonitorAdditionalInfo(modeInfoArray[iMode].adapterId, modeInfoArray[iMode].id);
}
catch (Exception)
{
additionalInfo[iMode].valid = false;
}
}
}
return true;
}
else
{
//Erreur : Querying display;
}
}
else
{
//Erreur : Taille Buffer;
}
return false;
}
Use ChangeDisplaySettingsEx function to change the settings of the specified display device to the specified graphics mode. The following is an example you can refer to.
#include <windows.h>
int main()
{
for (DWORD devNum = 0; ; devNum++)
{
DISPLAY_DEVICE dev = {0};
dev.cb = sizeof(DISPLAY_DEVICE);
if (!EnumDisplayDevices(NULL, devNum, &dev, EDD_GET_DEVICE_INTERFACE_NAME))
break;
wprintf(L"Display name: %s \n", dev.DeviceName);
DEVMODE dMode = { 0 };
dMode.dmSize = sizeof(dMode);
if (!EnumDisplaySettings(dev.DeviceName, ENUM_CURRENT_SETTINGS, &dMode))
{
wprintf(L"EnumDisplaySettings error: %d \n", GetLastError());
continue;
}
wprintf(L"Display old settings: \n");
wprintf(L"dmBitsPerPel: %d \n", dMode.dmBitsPerPel);
wprintf(L"dmPelsWidth: %d \n", dMode.dmPelsWidth);
wprintf(L"dmPelsHeight: %d \n", dMode.dmPelsHeight);
wprintf(L"dmDisplayFlags: %x \n", dMode.dmDisplayFlags);
wprintf(L"dmDisplayFrequency: %d \n", dMode.dmDisplayFrequency);
dMode.dmPelsWidth = 800;
dMode.dmPelsHeight = 600;
ChangeDisplaySettingsEx(dev.DeviceName, &dMode, NULL, 0, NULL);
DEVMODE dModeNew = { 0 };
dModeNew.dmSize = sizeof(DEVMODE);
if (!EnumDisplaySettings(dev.DeviceName, ENUM_CURRENT_SETTINGS, &dModeNew))
{
wprintf(L"EnumDisplaySettings error: %d \n", GetLastError());
continue;
}
wprintf(L"Display new settings: \n");
wprintf(L"dmBitsPerPel: %d \n", dModeNew.dmBitsPerPel);
wprintf(L"dmPelsWidth: %d \n", dModeNew.dmPelsWidth);
wprintf(L"dmPelsHeight: %d \n", dModeNew.dmPelsHeight);
wprintf(L"dmDisplayFlags: %x \n", dModeNew.dmDisplayFlags);
wprintf(L"dmDisplayFrequency: %d \n", dModeNew.dmDisplayFrequency);
}
getchar();
}
I set dwflags to 0 let the graphics mode for the current screen change dynamically. Refer to dwflags parameter part of ChangeDisplaySettingsEx's document for deciding how you would like the graphics mode should be changed.