Windows下提示显示器信息主要通过两个函数实现。一个是EnumDisplayDevices()， 另一个是EnumDisplayMonitors().
EnumDisplayDevices()枚举所有显示设备，而EnumDisplayMonitors枚举的是所有显示器。
显示设备和显示器不一样，比如显卡算显示设备，但是不是显示器。
EnumDisplayMonitors()还会枚举出不可见的伪显示器，如果只是想得到实际的显示器数目的话可以用GetSystemMetrics(SM_CMONITORS)，该函数不包括虚拟显示器。

MonitorInfoex 和MonitorInfo 在这两个结构中保存着相应显示器的相关信息,如坐标、是否为主显示器等

GetMonitorInfo ( ) 　取得指定显示器的相关信息,如物理显示区大小等
MonitorFromPoint ( ) 　取得指定点所在的显示器句柄
MonitorFromRect ( ) 　取得指定矩形所在的显示器句柄
MonitorFromWindow( ) 　取得指定窗口所在的显示器句柄
MonitorEnumProc( ) 当应用程序调用EnumDisplayMonitors ( )查询显示器个数时,系统自动为每一个显示器调用一次该函数。应用程序可以依此判断显示器的个数、位置及显示区域的大小等信息

函数名：MonitorEnumProc（）
输入参数：HMONITOR hMonitor ---显示器句柄
          HDC hdcMonitor  ----显示器DC句柄
        LPRECT lprcMonitor-----
        LPARAM dwData-----EnumDisplayMonitors传来的数据
返回：bool
功能：若返回为真，EnumDisplayMonitors继续枚举，
      若返回为假，EnumDisplayMonitors停止枚举，从而获得显示器信息

MonitorAdapter.h

#include <atlstr.h>
#include <vector>
#include <WinDef.h>
#include <tchar.h>
using std::vector;using namespace std;#define MAX_MONITOR_NAME 256static std::vector<HMONITOR> g_hMonitorGroup;  // 显示器模式信息
typedef struct MonitorModeInfo_t
{unsigned int m_nWidth;             unsigned int m_nHeight;MonitorModeInfo_t(int nWidth, int nHeight) : m_nWidth(nWidth), m_nHeight(nHeight) {}
}MonitorModeInfo;// 显示器信息
struct MonitorInfo
{TCHAR szDevice[MAX_MONITOR_NAME];                  // 显示器名称std::vector<MonitorModeInfo> m_vecModeInfo;           // 当前名称的显示器支持的分辨率模式
};typedef std::vector<MonitorInfo> VEC_MONITORMODE_INFO;  // 所有的显示器信息 class MonitorAdapter
{
public:MonitorAdapter();~MonitorAdapter();// 回调函数static int CALLBACK MonitorEnumProc(HMONITOR hMonitor, HDC hdc,LPRECT lpRMonitor,LPARAM dwData);// 得到所有显示器的名称void GetAllMonitorName(VEC_MONITORMODE_INFO& m_vecMonitorListInfo);// 得到所有显示器的模式void GetAllDisplayMode(VEC_MONITORMODE_INFO& m_vecMonitorListInfo);//得到屏幕当前分辨率void GetCurrentReselotion(int& nWidth,int& nHeight,int& nFreq,int& nBits);//根据屏幕ID取获取屏幕的对应分辨率void GetCurrentReselotion(LPCWSTR lpszDeviceName, int& nWidth, int& nHeight, int& nFreq, int& nBits);//修改分辨率int ChangMonitorReselotion(HMONITOR hMonitor,const int nWidth,const int nHight,const int nFre,const int nColorBits);
};

MonitorAdapter.cpp

#include "stdafx.h"
#include "MonitorAdapter.h"MonitorAdapter::MonitorAdapter(void)
{
}MonitorAdapter::~MonitorAdapter(void)
{
}int CALLBACK MonitorAdapter::MonitorEnumProc(HMONITOR hMonitor, HDC hdc,LPRECT lpRMonitor,LPARAM dwData)
{g_hMonitorGroup.push_back(hMonitor);return 1;
}// 得到所有显示器的名称
void MonitorAdapter::GetAllMonitorName(VEC_MONITORMODE_INFO& vecMonitorListInfo)
{g_hMonitorGroup.clear();::EnumDisplayMonitors(NULL, NULL, MonitorEnumProc, 0);//vector<HMONITOR>::iterator ithMoniter = g_hMonitorGroup.begin();for(int i = 0; i < g_hMonitorGroup.size();i++){MONITORINFOEX mixTemp;memset(&mixTemp, 0, sizeof(MONITORINFOEX));mixTemp.cbSize = sizeof(MONITORINFOEX);GetMonitorInfo(g_hMonitorGroup[i], &mixTemp);VEC_MONITORMODE_INFO::iterator itBeg = vecMonitorListInfo.begin();VEC_MONITORMODE_INFO::iterator itEnd = vecMonitorListInfo.end();for(; itBeg != itEnd; ++itBeg){if( 0 == _tcscmp(mixTemp.szDevice, itBeg->szDevice)){break;}}//没有在列表中找到,则需要添加if (itBeg == itEnd)       {MonitorInfo tmpMonitorInfo;_tcscpy_s(tmpMonitorInfo.szDevice, sizeof(tmpMonitorInfo.szDevice), mixTemp.szDevice);vecMonitorListInfo.push_back(tmpMonitorInfo);}}
}// 得到所有显示器的模式
void MonitorAdapter::GetAllDisplayMode(VEC_MONITORMODE_INFO& vecMonitorListInfo)
{GetAllMonitorName(vecMonitorListInfo);bool      bRetVal;DEVMODE     devmode;VEC_MONITORMODE_INFO::iterator itBeg = vecMonitorListInfo.begin();VEC_MONITORMODE_INFO::iterator itEnd = vecMonitorListInfo.end();for (NULL; itBeg != itEnd; ++itBeg){int iMode = 0;do{bRetVal = ::EnumDisplaySettings(itBeg->szDevice, iMode, &devmode);iMode++;if (bRetVal){bool bFind = false;vector<MonitorModeInfo>::iterator itBeg_Mode = itBeg->m_vecModeInfo.begin();vector<MonitorModeInfo>::iterator itEnd_Mode = itBeg->m_vecModeInfo.end();for (NULL; itBeg_Mode != itEnd_Mode; ++itBeg_Mode){// 如果已经在列表中找到,则结束本次循环if ((itBeg_Mode->m_nWidth == devmode.dmPelsWidth) && (itBeg_Mode->m_nHeight == devmode.dmPelsHeight)){bFind = true;break;}// 插入数据时,从 大到小排列 (按windows 分辨率设置,优先比较 宽) if ((itBeg_Mode->m_nWidth < devmode.dmPelsWidth) ||((itBeg_Mode->m_nWidth == devmode.dmPelsWidth) && (itBeg_Mode->m_nHeight < devmode.dmPelsHeight))){                           break;}}if(!bFind){if (itBeg_Mode == itEnd_Mode){itBeg->m_vecModeInfo.push_back(MonitorModeInfo(devmode.dmPelsWidth, devmode.dmPelsHeight)); }else{itBeg->m_vecModeInfo.insert(itBeg_Mode, MonitorModeInfo(devmode.dmPelsWidth, devmode.dmPelsHeight)); }}}}while (bRetVal); }
}int MonitorAdapter::ChangMonitorReselotion(HMONITOR hMonitor,const int nWidth,const int nHight,const int nFre,const int nColorBits)
{if ( NULL == hMonitor ){return -1;}MONITORINFOEX mi;mi.cbSize = sizeof(mi);GetMonitorInfo( hMonitor , &mi);DEVMODE DeviceMode;ZeroMemory(&DeviceMode, sizeof(DEVMODE));DeviceMode.dmSize = sizeof(DEVMODE); BOOL bFlag = TRUE;bFlag = EnumDisplaySettings(mi.szDevice, ENUM_CURRENT_SETTINGS, &DeviceMode);if ( bFlag != TRUE ){return -1;} if (DeviceMode.dmPelsWidth == nWidth && DeviceMode.dmPelsHeight == nHight ){return 0;}DeviceMode.dmDisplayFlags = 0;DeviceMode.dmPelsWidth= nWidth;       DeviceMode.dmPelsHeight = nHight;DeviceMode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_DISPLAYFREQUENCY ;int nRet = ChangeDisplaySettingsEx(mi.szDevice, &DeviceMode, NULL, CDS_GLOBAL | CDS_NORESET | CDS_UPDATEREGISTRY, NULL);if (DISP_CHANGE_BADMODE == nRet){ChangeDisplaySettingsEx(mi.szDevice, &DeviceMode, NULL, CDS_GLOBAL | CDS_NORESET | CDS_UPDATEREGISTRY, NULL);      }if ( DISP_CHANGE_SUCCESSFUL == nRet ){return 0;}return -1;
}void MonitorAdapter::GetCurrentReselotion(int& nWidth,int& nHeight,int& nFreq,int& nBits)
{DEVMODE DeviceMode;EnumDisplaySettings(NULL, ENUM_CURRENT_SETTINGS, &DeviceMode);nWidth = DeviceMode.dmPelsWidth;nHeight = DeviceMode.dmPelsHeight;nFreq = DeviceMode.dmDisplayFrequency;nBits = DeviceMode.dmBitsPerPel;
}void MonitorAdapter::GetCurrentReselotion(LPCWSTR lpszDeviceName, int& nWidth, int& nHeight, int& nFreq, int& nBits)
{DEVMODE DeviceMode;EnumDisplaySettings(lpszDeviceName, ENUM_CURRENT_SETTINGS, &DeviceMode);nWidth = DeviceMode.dmPelsWidth;nHeight = DeviceMode.dmPelsHeight;nFreq = DeviceMode.dmDisplayFrequency;nBits = DeviceMode.dmBitsPerPel;
}

test

#include "stdafx.h"
#include "MonitorAdapter.h"int _tmain(int argc, _TCHAR* argv[])
{MonitorAdapter         m_monitorAdapter;       //显示器VEC_MONITORMODE_INFO vecMointorListInfo;m_monitorAdapter.GetAllDisplayMode(vecMointorListInfo);int nWidth = 0, nHeight = 0, nFreq = 0, nBits = 0;VEC_MONITORMODE_INFO::iterator itBeg = vecMointorListInfo.begin();for (int i = 0; i < vecMointorListInfo.size();i++){//得到当前显示器分辨率 刷新率 色位m_monitorAdapter.GetCurrentReselotion(itBeg->szDevice, nWidth, nHeight, nFreq, nBits);itBeg++;nWidth = 0, nHeight = 0, nFreq = 0, nBits = 0;}return 0;
}