C++ launching program without console opening - c++

Question

I have been working on an application to set the desktop background basing of another application I found here: http://www.optimumx.com/downloads.html#SetWallpaper. The idea is to set the background to a wallpaper every 10 minutes, so it launches the SetWallpaper.exe with the command 'SetWallpaper.exe /D:S Wallpaper.jpg' but when I launch my application it creates a console window that doesn't automatically close and when I manually close it, it kills the exe.
#include <windows.h>
int main() {
int i = 1;
int j = 3;
// refresh = time until refresh in minutes
int refresh = 10;
// 1000 milliseconds = 1 second
int second = 1000;
int minute = 60;
int time = second * minute * refresh;
while (i < j) {
system("cmd /c start /b SetWallpaper.exe /D:S Wallpaper.jpg");
Sleep(time);
}
return 0;
}
I tried using 'sleep.exe' that comes with MinGW Msys but that creates a new process each team, eventually hogging all the processes.
Thanks in advance!

Answer 1

The first problem you're having is that you've created your program as a console application with a main method. Instead, create it as a Win32 Project with a WinMain entry point. This will be invoked directly without creating a console window.
EDIT: The second issue is addressed by Ferruccio's answer in that you're invoking another console application from yours which will also result in a console window being created.

Answer 2

You're going about it the hard way. It's fairly simple to change the Windows wallpaper in a program:
#include <windows.h>
SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, (PVOID) "path/to/wallpaper.jpg", SPIF_UPDATEINIFILE);
In any case, if you insist on launching an external program to do it. Use CreateProcess. It has the ability to launch console mode apps without a visible window, by setting the dwCreationFlags parameter to CREATE_NO_WINDOW.

Answer 3

Set ShowWindow to false and don't forget to FreeConsole at the end.
#include <windows.h>
int main(void)
{
ShowWindow(FindWindowA("ConsoleWindowClass", NULL), false);
// put your code here
system("cmd /c start /b SetWallpaper.exe /D:S Wallpaper.jpg");
FreeConsole();
return 0;
}
And as Ferruccio mentioned, You can use SetTimer and SystemParametersInfo to trigger a change periodically.
#define STRICT 1
#include <windows.h>
#include <iostream.h>
VOID CALLBACK TimerProc(HWND hWnd, UINT nMsg, UINT nIDEvent, DWORD dwTime)
{
LPWSTR wallpaper_file = L"C:\\Wallpapers\\wallpaper.png";
int return_value = SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, wallpaper_file, SPIF_UPDATEINIFILE);
cout << "Programmatically change the desktop wallpaper periodically: " << dwTime << '\n';
cout.flush();
}
int main(int argc, char *argv[], char *envp[])
{
int Counter=0;
MSG Msg;
UINT TimerId = SetTimer(NULL, 0, 2000, &TimerProc); //2000 milliseconds = change every 2 seconds
cout << "TimerId: " << TimerId << '\n';
if (!TimerId)
return 16;
while (GetMessage(&Msg, NULL, 0, 0))
{
++Counter;
if (Msg.message == WM_TIMER)
cout << "Counter: " << Counter << "; timer message\n";
else
cout << "Counter: " << Counter << "; message: " << Msg.message << '\n';
DispatchMessage(&Msg);
}
KillTimer(NULL, TimerId);
return 0;
}