Using TextOut() to display a number

[Fujy]

So, I want to use the TextOut function to display an integer in my window.

Here`s a piece of my code :

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	int wmId, wmEvent;
	PAINTSTRUCT ps;
	HDC hdc;
	int anumber = 100;
	switch (message)
	{
	case WM_COMMAND:
		wmId    = LOWORD(wParam);
		wmEvent = HIWORD(wParam);
		// Parse the menu selections:
		switch (wmId)
		{
		case IDM_ABOUT:
			DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
			break;
		case IDM_EXIT:
			DestroyWindow(hWnd);
			break;
		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
		}
		break;
	case WM_PAINT:
		hdc = BeginPaint(hWnd, &ps);
		TextOut(hdc, 20, 20, L"Here is a number : " + anumber, 22);
		EndPaint(hWnd, &ps);
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	default:
		return DefWindowProc(hWnd, message, wParam, lParam);
	}
	return 0;
}

I posted only this much because it would have been a waste of room the post the whole code.
Can anybody help ?

[Sebastiani]

>> TextOut(hdc, 20, 20, L"Here is a number : " + anumber, 22);

char* + int == char*

Hint: use ssprintf, et al.

[Fujy]

Don`t really know what you mean, but isn`t sprintf a function in C (I should have specified that my app is a Win32 C++ GUI-based one.) ? And ... what do you mean by "char* + int == char*" ?

[vart]

you need to use sprintf (if you use C) or std::stringstream (if you prefer C++) to convert integer to string

after that you use your current function to output text string

[Fujy]

Thanks, works now.

[novacain]

Just as a note....

Any variable declared in the callback has very limited scope (lifetime). Each message that is processed means a new 'copy' of the variable.

If you want the variable to retain its value for the life of the app (not just for one individual message), use 'static' variables in the callback.

EDIT: I advise you to use _snprintf() or similar versions. sprintf() may/will crash your app if the resultant string is equal to or exceeds the lenght of the char array.

char szBuf[3]={0};
int    iNum=123;

sprintf(sBuf, "%d", iNum);// this may crash your app

_snprintf(sBuf, 2, "%d" , iNum); //will only print '12' but will not crash app