Win32 : unable to set window title

Question

Hi,

I'm working on win32 desktop application. I used CreateWindowExW() API to create a window.

                LPCWSTR         title = L"SAMPLE TITLE";

            // Create Window With properties

            window = CreateWindowExW (NULL,
                                      windowclassname,
                                      title,
                                      windowstyle,
                                      (int) pInstructionSet[pIndex]->GetXPos (), (int) pInstructionSet[pIndex]->GetYPos (), (int) pInstructionSet[pIndex]->GetWidth (), (int) pInstructionSet[pIndex]->GetHeight (),
                                      NULL,
                                      NULL,
                                      hinstance,
                                      NULL
            );

I created a LPCWSTR string as a title and set that title in CreateWindowExW() api, but when the window came up, i can only see the first character of my title in window title.

How to fix this issue, did I miss anything here?

Thank you.

Answer 1

I used a very minimal Windows Application for testing. The application only uses the "W" versions of Windows API functions to create a UNICODE Window. The Character set property of the project was configured as "Not Set".

Sample for testing -

#include <windows.h>
#include <stdio.h>


HINSTANCE hInst;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

LPCWSTR pwszTitle = L"Sample Title";


int APIENTRY wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPWSTR lpCmdLine, _In_ int nCmdShow)
{
    hInst = hInstance;
    WNDCLASSW wc =
    {
        CS_HREDRAW | CS_VREDRAW, WndProc, 0, 0, hInst, LoadIconW(NULL, MAKEINTRESOURCEW(32512)),
        LoadCursorW(NULL, MAKEINTRESOURCEW(32512)), (HBRUSH)(COLOR_WINDOW + 1), NULL, L"WindowClass"
    };

    if (!RegisterClassW(&wc))
        return MessageBoxW(NULL, L"RegisterClassExW failed!", L"Error", MB_ICONERROR | MB_OK);

    HWND hWnd = CreateWindowExW(0, wc.lpszClassName, pwszTitle, WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInst, NULL);

    if (!hWnd)
        return MessageBoxW(NULL, L"CreateWindowExW failed", L"Error", MB_ICONERROR | MB_OK);

    ShowWindow(hWnd, SW_SHOWNORMAL);
    UpdateWindow(hWnd);

    MSG msg;
    while (GetMessageW(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessageW(&msg);
    }

    return (int)msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
/*
    case WM_NCCREATE:
        {
            WCHAR szMsg[128];
            LPCREATESTRUCTW lpcs = (LPCREATESTRUCTW)lParam;
            swprintf_s(szMsg, L"In WM_NCCREATE, Window Class: %s, Window Title: %s\n", lpcs->lpszClass, lpcs->lpszName);
            OutputDebugStringW(szMsg);
            return TRUE;
        }
        break;

    case WM_CREATE:
        {
        WCHAR szMsg[128];
        LPCREATESTRUCTW lpcs = (LPCREATESTRUCTW)lParam;
        swprintf_s(szMsg, L"In WM_CREATE, Window Class: %s, Window Title: %s\n", lpcs->lpszClass, lpcs->lpszName);
        OutputDebugStringW(szMsg);
        }
        break;
*/
    case WM_DESTROY:
            PostQuitMessage(0);
            break;

        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
    }

    return 0;
}

When the handlers for WM_NCCREATE and WM_CREATE are commented out the window caption is truncated as described by the Questioner. However, I can think of no reason for this to happen!

Spy++ shows that a UNICODE window was created but the UNICODE text passed to CreateWindowExW was truncated anyway!

Then when the WM_NCCREATE and WM_CREATE handlers are uncommented the created window has no caption at all!

And the debug output from the two handlers shows the proper UNICODE text for the Window caption -

I don't understand why passing UNICODE text to a "W" API function for a UNICODE window causes such unexpected results. It doesn't seem to me that the project character set property is relevant in this example.

Answer 2

It almost is caused by Use Multi-Byte Character Set project setting. The same behavior will arise when I change the new created Windows Desktop Application to Use Multi-Byte Character Set.