Thread: Message Box in C++

Hi.
I have a question, I like the MessageBox in my my program but not to much windows. I created this little program in a couple of minuts but I have a problem: I really like that before the program starts that he ask if you want to you it, that's quite simple but I want the MessageBox who ask if you want to use it, displaying first before the black Win 32 Console screen (*.exe) displays (shows up) and that if you click on "No" that he quits ( exit (0); ) but if you quit the Win 32 Console still mussn't be displayed and "Yes", then it starts:

Code:

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

using namespace std;

int one;
int two;
int three;
int four;

int main()
{
    cout<<"Hi there, typ in 100: ";
    cin>> one;
    cout<<endl;
    
    if ( one == 100 ){
    cout<<endl;
    cout<<"Good, thanks for using this software."<<endl;
    cout<<endl;
    
    Sleep(3000);
 	three = MessageBox( 0, "Do you want to quit?", "Quit", 4 );
    
 	if (three == IDNO){
    main();
    }
    }
    
	else{
    cout<<endl;
    cout<<"You need to typ 100 not something else!"<<endl;
    cout<<endl;
    cout<<"Do you want to try again or quit? Press 1 to try again, 2 to stop: ";
    cin>> two;
    cout<<endl;
    }
    
    if ( two == 1 ){
    main();
    }
    
    else{
    four = MessageBox( 0, "Thank you for using this software!", "Bye", MB_ICONEXCLAMATION );
    
    if (four == IDOK){
    cout<<"BYEEEEEEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!"<<endl;
    cout<<endl;
    Sleep(1000);
    exit(0);
    }
    }
}

I don't know much about all that windows code (only MB, a bit), maybe it is possible in C++ but if it just works it's fine.

Code:

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


int main()
{
	int iRet = ::MessageBox(0, "rawr", "rawr", MB_YESNO);

	if(iRet == IDYES) std::cout << "You pressed yes";
	else std::cout << "You pressed no probably";

	return 0;
}

It's self explanitory. Resources used to make this code: http://msdn.microsoft.com/library/de...messagebox.asp I suggest always checking MSDN for your win32 needs. Check the return value table for other MessageBox returns for other style types. "Not knowing much about windows code" is no excuse to ignore the vast resources at your fingertips!

1. If I use your code (Tonto) it still opens the Win 32 Console screen and a Message Box but what I want is that he first opens the Message Box and if you click on "Yes" then he opens the Win 32 screen whith the rest of the program and if you click on "No" then he just quits.
2. I don't get it, what is wrong whith "main();" please explain me better, I am still learning.

1) Okay. I do not actually know how this could be done with a console window without using a 'hackish' method like ShowWindow(hwnd, SW_HIDE); further hacking stuff up with a FindWindow to obtain the console window handle, and then conditionally re-shwoing it once the user clicks. I mean if that's fine for you, whatev, however, I highly suggest getting into fullblown win32 programming. This tutorial" http://www.functionx.com/win32/ is very in detail. Then you can put the MessageBox before everything, and then CreateWindow[Ex] afterwards. This makes the particular task much easier.

2) May I quote a nice article? It explains the asm RET and CALL instruction very well.

Originally Posted by http://www.enderunix.org/docs/eng/bof-eng.txt

...However, ix86 processor family provides us with two instructions: CALL and
RET, making our lives easy! the CALL instruction writes that "next instruction
to be executed after function returns" (from then on, we'll call this
as the "return address") to the stack. It PUSHes it onto the stack, and writes
the address of the function to EIP. Thus, a function call is made. The RET
instruction, on the other hand, POPs the "return address" from the stack, and
writes that address in the EIP. Thus we'll safely return from the function,
and continue with the program's next thread of execution.

Because you are calling main recursively however, you just keep going down down down into the memory, and you never return from all the call's that you've been making. It breaks one of the fundamental thingies of recursion, that you have a "check" so that when a condition is met you pop back you of all the frames you've "allocated". So if you call main() recursively like you do enough times, it would just like make the stack and computer explode, and your pets would die, and your socialife would fall apart, etc.

How do I need to use "ShowWindow(hwnd, SW_HIDE);" if I use it it doens't do anything if I use it like this:

Code:

    HWND hwnd;
    ShowWindow(hwnd, SW_HIDE);

Thanks anyway but it would really help if it worked.

So... how does it work then?

Technique described at gamedev or codeguru I think. Dunno. Very very ugly and hackish.

Code:

#include <windows.h>
#include <iostream>
int main(int argc, char* argv[])
{
	char szOld[200];
	char szNew[200] = "hello";
	int iRet;

	::GetConsoleTitle(szOld, 200);
	::SetConsoleTitle(szNew);
	::Sleep(100);



	HWND hwnd = ::FindWindow(NULL, szNew);
	if(!hwnd)
	{
		::MessageBox(0, "Window handle not obtained", "wtf", MB_OK);
		return 0;
	}

	::SetConsoleTitle(szOld);
	::ShowWindow(hwnd, SW_HIDE);

	if((iRet = ::MessageBox(0, "I'm asking you a question ..........", "rwawrwarr", MB_YESNO)) == IDYES)
	{
		::ShowWindow(hwnd, SW_SHOWNORMAL);
	}
	
	return 0;
}

I eluded to this without providing the code in my post above saying:

Originally Posted by Me

...further hacking stuff up with a FindWindow to obtain the console window handle...

According to the C++ standard you should not call main from anywhere in your program.

Ok, thanks it works it still shows up for a little time but that doesn't care.