C++：類EnumDisplayMonitors回調

Question

我有一個EnumDisplayMonitors回調的問題。我想獲得每個屏幕的數量和屏幕分辨率。它似乎正在使用此代碼。

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

#pragma comment(lib, "user32.lib") 

std::vector< std::vector<int> > screenVector; 
int screenCounter = 0; 

BOOL CALLBACK MonitorEnumProcCallback( _In_ HMONITOR hMonitor, 
             _In_ HDC hdcMonitor, 
             _In_ LPRECT lprcMonitor, 
             _In_ LPARAM dwData) { 
    screenCounter++; 

    MONITORINFO info; 
    info.cbSize = sizeof(MONITORINFO); 

    BOOL monitorInfo = GetMonitorInfo(hMonitor,&info); 

    if(monitorInfo) { 
     std::vector<int> currentScreenVector; 
     currentScreenVector.push_back(screenCounter); 
     currentScreenVector.push_back(abs(info.rcMonitor.left - info.rcMonitor.right)); 
     currentScreenVector.push_back(abs(info.rcMonitor.top - info.rcMonitor.bottom)); 
     std::cout << "Monitor " 
        << currentScreenVector.at(0) 
        << " -> x: " 
        << currentScreenVector.at(1) 
        << " y: " 
        << currentScreenVector.at(2) 
        << "\n";  
    } 

    return TRUE; 
} 

int main() { 
    BOOL b = EnumDisplayMonitors(NULL,NULL,MonitorEnumProcCallback,0); 
    system("PAUSE"); 
    return 0; 
} 

但是，當我將所有內容都傳遞給我的實際代碼庫幷包含在類中時，它將返回一個錯誤。我不知道我是否做得對。 - >這裏的片段：

ScreenManager::ScreenManager() { 
    BOOL monitorInitialized = EnumDisplayMonitors(NULL, NULL, MonitorEnumProc, reinterpret_cast<LPARAM>(this)); 
} 

BOOL CALLBACK MonitorEnumProc( HMONITOR hMonitor, 
           HDC hdcMonitor, 
           LPRECT lprcMonitor, 
           LPARAM dwData) { 

    reinterpret_cast<ScreenManager*>(dwData)->callback(hMonitor,hdcMonitor,lprcMonitor); 
    return true; 
} 

bool ScreenManager::callback(HMONITOR hMonitor, HDC hdcMonitor, LPRECT lprcMonitor){ 

    screenCounter++; 

    MONITORINFO info; 
    info.cbSize = sizeof(MONITORINFO); 

    BOOL monitorInfo = GetMonitorInfo(hMonitor,&info); 

    if(monitorInfo) { 
     std::vector<int> currentScreenVector; 
     currentScreenVector.push_back(screenCounter); 
     currentScreenVector.push_back(abs(info.rcMonitor.left - info.rcMonitor.right)); 
     currentScreenVector.push_back(abs(info.rcMonitor.top - info.rcMonitor.bottom)); 

    } 

    return true; 
} 

Answer 1

我只是通過改變回調函數，以公衆解決我的問題。