用于分离辅助监视器的 C++ 应用程序

Question

我正在尝试创建一个应用程序以从 Windows 机器上分离辅助监视器(长话短说)。

这是我用作基础的 Microsoft 示例代码: http://support.microsoft.com/kb/308216/en-us

这是我的代码:

#include <iostream>
#include <windows.h>

void DetachDisplay()
{
    BOOL            FoundSecondaryDisp = FALSE;
    DWORD           DispNum = 0;
    DISPLAY_DEVICE  DisplayDevice;
    LONG            Result;
    TCHAR           szTemp[200];
    int             i = 0;
    DEVMODE   defaultMode;

    // initialize DisplayDevice
    ZeroMemory(&DisplayDevice, sizeof(DisplayDevice));
    DisplayDevice.cb = sizeof(DisplayDevice);

    // get all display devices
    while (EnumDisplayDevices(NULL, DispNum, &DisplayDevice, 0))
        {
        ZeroMemory(&defaultMode, sizeof(DEVMODE));
        defaultMode.dmSize = sizeof(DEVMODE);
        if ( !EnumDisplaySettings((LPSTR)DisplayDevice.DeviceName, ENUM_REGISTRY_SETTINGS, &defaultMode) )
                  OutputDebugString("Store default failed\n");

        if ((DisplayDevice.StateFlags & DISPLAY_DEVICE_ATTACHED_TO_DESKTOP) &&
            !(DisplayDevice.StateFlags & DISPLAY_DEVICE_PRIMARY_DEVICE))
            {
            DEVMODE    DevMode;
            ZeroMemory(&DevMode, sizeof(DevMode));
            DevMode.dmSize = sizeof(DevMode);
            DevMode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_POSITION
                        | DM_DISPLAYFREQUENCY | DM_DISPLAYFLAGS ;
            Result = ChangeDisplaySettingsEx((LPSTR)DisplayDevice.DeviceName, &DevMode, NULL, CDS_UPDATEREGISTRY, NULL);
            //Result = ChangeDisplaySettingsEx((LPSTR)DisplayDevice.DeviceName, &DevMode, NULL, CDS_UPDATEREGISTRY, NULL);
            ChangeDisplaySettingsEx (NULL, NULL, NULL, 0, NULL);


            //The code below shows how to re-attach the secondary displays to the desktop

            //ChangeDisplaySettingsEx((LPSTR)DisplayDevice.DeviceName, &defaultMode, NULL, CDS_UPDATEREGISTRY, NULL);
            //ChangeDisplaySettingsEx((LPSTR)DisplayDevice.DeviceName, &defaultMode, NULL, CDS_UPDATEREGISTRY, NULL);

            }

        // Reinit DisplayDevice just to be extra clean

        ZeroMemory(&DisplayDevice, sizeof(DisplayDevice));
        DisplayDevice.cb = sizeof(DisplayDevice);
        DispNum++;
        } // end while for all display devices
}

int main()
{
    DetachDisplay();
    return 0;
}

然而，当我编译并运行它时，我得到的只是屏幕闪烁，好像它正在改变分辨率但它实际上并没有做任何有意义的事情(我确实注意到鼠标移动了......但除此之外什么都没有) .

也许其他人已经创建了一个实用程序来执行这个确切的功能，如果可以从命令行调用它，效果会一样好。

想法？

Answer 1

您可以使用 SetDisplayConfig 在 Windows 7 中执行此操作。下面的示例禁用所有辅助屏幕。

UINT32 NumPathArrayElements = 0;
UINT32 NumModeInfoArrayElements = 0;
LONG error = GetDisplayConfigBufferSizes(QDC_ONLY_ACTIVE_PATHS,&NumPathArrayElements,&NumModeInfoArrayElements); 
std::vector<DISPLAYCONFIG_PATH_INFO> PathInfoArray(NumPathArrayElements);
std::vector<DISPLAYCONFIG_MODE_INFO> ModeInfoArray(NumModeInfoArrayElements);
error = QueryDisplayConfig(QDC_ONLY_ACTIVE_PATHS,&NumPathArrayElements, &PathInfoArray[0],&NumModeInfoArrayElements, &ModeInfoArray[0],NULL);

for(unsigned int i=0;i<PathInfoArray.size();++i){
    if(PathInfoArray[i].sourceInfo.modeInfoIdx<ModeInfoArray.size()){
        int modeIndex=PathInfoArray[i].sourceInfo.modeInfoIdx;
        _POINTL pos=ModeInfoArray[modeIndex].sourceMode.position;
        if(pos.x!=0 || pos.y!=0){
            PathInfoArray[i].flags=0;
            break;
        }
    }
}
error = SetDisplayConfig(NumPathArrayElements, &PathInfoArray[0],NumModeInfoArrayElements, &ModeInfoArray[0],(SDC_APPLY | SDC_ALLOW_CHANGES | SDC_USE_SUPPLIED_DISPLAY_CONFIG));

有关所用函数的更多信息:http://msdn.microsoft.com/en-us/library/ff539596%28v=VS.85%29.aspx