I just solved my problem by changing the callback function to public.
C++: EnumDisplayMonitors callback inside a class
Pergunta
I have a problem with EnumDisplayMonitors callbacks. I want to get the number of screens and the screen resolutions of each one. It seems that it's working using this code.
#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;
}
But when I transferred everything to my actual codebase and contained inside a class, it's returning an error. I don't know if I'm doing this right. -> Here's the snippet:
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;
}
Solução
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