I'm learning API programming and used "MessageBoxW" to show Arabic unicode characters but this small program failed to show the Arabic characters correctly and rather of that it shows characters have no sense:
#include <windows.h>
#include <tchar.h>
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
MessageBoxW (NULL, _TEXT (L"بسم الله الرحمن الرحيم"), _TEXT (L"HelloMsg"), 0) ;
return 0 ;
}
Related
I'm trying to display the command line arguments.
This is my current code.
#include "windows.h"
int _stdcall WinMain ( HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpszCmdline,
int nCmdShow )
{
MessageBox ( 0, lpszCmdLine,L"Title",0);
return ( 0 ) ;
}
I'm getting different characters in application.
What changes should I do in order to display the command line arguments in application window?
Since lpszCmdline is LPSTR, (ASCII, not UNICODE), the first option would be using the ASCII version of MessageBox(), but since UNICODE is the standard, I would suggest using the UNICODE version of win32 entry point. See the code below:
#include "windows.h"
int _stdcall wWinMain ( HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPWSTR lpszCmdline,
int nCmdShow )
{
MessageBox ( 0, lpszCmdLine,L"Title",0);
return ( 0 ) ;
}
Further more, to convert the command line to an argv style array of strings, call the CommandLineToArgvW function.
I need to create an exe application with no console window or (any other window) during the start up of the application.
I tried the below for this:
Using Visual Studio 2010, created a Win32 Console Application as an Empty Project.
Added a header file "stdafx.h" to the project
Added a cpp file to the project and added the below code.
The project settings are visual stduio default.
#include "stdafx.h"
#include <windows.h>
#include "TlHelp32.h"
#include <iostream>
#include <string>
int APIENTRY WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow)
{
return 0;
}
The above code compiles good.
But if I change the Character Set to "Use Unicode Character Set", I am getting the following compilation error.
error C2731: 'WinMain' : function cannot be overloaded
I am building the application on a Windows 7 64 bit computer and Visual Studio Build platform as x64.
Thanks in advance for your help.
Yes, when you build with UNICODE in effect then the entrypoint takes a Unicode string for the command line argument. So that requires a different declaration:
int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPWSTR lpCmdLine, int nShowCmd)
Or you can use #include <tchar.h> so it works either way, not much point to it these days:
int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPTSTR lpCmdLine, int nCmdShow)
Create Windows service instead console app.
In Visual Studio, create a new "EMPTY Project". Add a new source file named "main.cpp". Use the following template (assumes you want to build with Unicode):
/************
main.cpp
************/
#define UNICODE 1
#include <windows.h>
int APIENTRY wWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPWSTR lpCmdLine, int nShowCmd)
{
// Process Return Codes
const int SUCCESS=0, FAILURE=1;
return SUCCESS;
}
int APIENTRY _tWinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPTSTR lpCmdLine,
int nCmdShow)
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
what's the purpose of UNREFERENCED_PARAMETER here?
It just suppresses a compiler warning about two parameters being unused in the function.
The macro itself is probably just defined as
#define UNREFERENCED_PARAMETER(x) (x)
so it references its argument but does nothing with it.
I created a win32 console application (without enable precompiled header option).
And now my source code as this, there is two compiler errors.
// AFormattingMsgBox.cpp : Defines the entry point for the console application.
//
#include <windows.h>
#include "stdafx.h"
//int _tmain(int argc, _TCHAR* argv[])
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
int cxScreen, cyScreen;
cxScreen = GetSystemMetrics(SM_CXSCREEN);
cyScreen = GetSystemMetrics(SM_CYSCREEN);
MessageBoxPrintf(TEXT("ScrnSize"), TEXT("The screen is %i pixels wide by %i pixels high."), cxScreen, cyScreen);
return 0;
}
int CDECL MessageBoxPrintf(TCHAR * szCaption, TCHAR * szFormat, int x, int y)
{
TCHAR szBuffer [1024];
va_list pArgList;
va_start(pArgList, szFormat);
_vsntprintf(szBuffer, sizeof(szBuffer) / sizeof(TCHAR),
szFormat, pArgList);
va_end(pArgList);
return MessageBox(NULL, szBuffer, szCaption, 0);
}
Compiler Errors.
error C3861: 'MessageBoxPrintf': identifier not found
error C2365: 'MessageBoxPrintf' : redefinition; previous definition was 'formerly
unknown identifier
How can I fix the errors. Thanks for your reading and replies.
Either put the function MessageBoxPrintf before the WinMain function or add a prototype before winMain. You add a prototype by entering the following line:
int CDECL MessageBoxPrintf(TCHAR * szCaption, TCHAR * szFormat, int x, int y);
I'm trying to learn OpenGL ES with the "OpenGL ES Training Course" (An OpenGL ES tutorial). I use OPENGL-ES 1.1 WINDOWS PC EMULATION with visual studio 2010. I'm trying to compile the 'hello triangle' program and get an error:
'WinMain': function cannot be overloaded
EDIT: I have only one definition of WinMain in the project: The one in the 'hello triangle' source code (which I didn't write).
Could anyone tell me what's going on?
It sounds like you have two definitions of WinMain, or perhaps a prototype and a definition that disagree.
I had the problem too. It showed that I have overloaded the function:
My old text:
#include "windows.h"
int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, long lpCmdLine, int nCmdShow)
{
}
and my new text:
int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
With the new text it works
Try
int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow){
// Your Code.
}
Instead Of
int WinMain(){
// Your Code.
}