How to fix "initialization of 'hwndButton' is skipped by 'case' label" and hwndButton' is skipped by 'default' label"

Question

I'm relatively new to programming and I wanted to try and see how to make a basic Windows Desktop Application in Visual Studio 2019. Since I added code for a button the C2360 and C2361 errors keep popping up and I don't know what in the code is causing it.

I've looked up solutions such as putting {} around the block of code and those don't seem to work.

// HelloWindowsDesktop.cpp
// compile with: /D_UNICODE /DUNICODE /DWIN32 /D_WINDOWS /c

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <tchar.h>

// Global variables

// The main window class name.
static TCHAR szWindowClass[] = _T("DesktopApp");

// The string that appears in the application's title bar.
static TCHAR szTitle[] = _T("WIndows Application test");

HINSTANCE hInst;

// Forward declarations of functions included in this code module:
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM );

int CALLBACK WinMain(
    _In_ HINSTANCE hInstance,
    _In_ HINSTANCE hPrevInstance,
    _In_ LPSTR     lpCmdLine,
    _In_ int       nCmdShow
)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = szWindowClass;
    wcex.hIconSm = LoadIcon(wcex.hInstance, IDI_APPLICATION);

    if (!RegisterClassEx(&wcex))
    {
        MessageBox(NULL,
            _T("Call to RegisterClassEx failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // Store instance handle in our global variable
    hInst = hInstance;

    // The parameters to CreateWindow explained:
    // szWindowClass: the name of the application
    // szTitle: the text that appears in the title bar
    // WS_OVERLAPPEDWINDOW: the type of window to create
    // CW_USEDEFAULT, CW_USEDEFAULT: initial position (x, y)
    // 500, 100: initial size (width, length)
    // NULL: the parent of this window
    // NULL: this application does not have a menu bar
    // hInstance: the first parameter from WinMain
    // NULL: not used in this application
    HWND hWnd = CreateWindow(
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        500, 100,
        NULL,
        NULL,
        hInstance,
        NULL
    );

    if (!hWnd)
    {
        MessageBox(NULL,
            _T("Call to CreateWindow failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // The parameters to ShowWindow explained:
    // hWnd: the value returned from CreateWindow
    // nCmdShow: the fourth parameter from WinMain
    ShowWindow(hWnd,
        nCmdShow);
    UpdateWindow(hWnd);

    // Main message loop:
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}

//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_PAINT    - Paint the main window
//  WM_DESTROY  - post a quit message and return
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps;
    HDC hdc;
    TCHAR greeting[] = _T("Hey Guys, this is my first Visual Studio desktop application, it has 158 lines of code!!!!!");

    switch (message)
    {
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);

        // Here your application is laid out.
        // For this introduction, we just print out "Hello, Windows desktop!"
        // in the top left corner.
        TextOut(hdc,
            5, 5,
            greeting, _tcslen(greeting));

        HWND hwndButton = CreateWindow(
            L"BUTTON",  // Predefined class; Unicode assumed 
            L"OK",      // Button text 
            WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,  // Styles 
            10,         // x position 
            10,         // y position 
            100,        // Button width
            100,        // Button height
            hWnd,     // Parent window
            NULL,       // No menu.
            (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
            NULL);      // Pointer not needed.

        // End application-specific layout section.

        EndPaint(hWnd, &ps);
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
        break;
    }

    return 0;
}

The expected output is of a new window with some text and a button to appear in the top left-hand corner but only the text appears. The following errors appear:

Error C2360, initialization of 'hwndButton' is skipped by 'case' label, line 149

Error C2361, initialization of 'hwndButton' is skipped by 'default' label, line 152

`HWND hwndButton = CreateWindow(` You are not allowed to create new variables inside a case. You could introduce a scope to get rid of the error. — drescherjm, Sep 09 '19 at 22:00
Possible duplicate of [Why can't variables be declared in a switch statement?](https://stackoverflow.com/questions/92396/why-cant-variables-be-declared-in-a-switch-statement) — drescherjm, Sep 09 '19 at 22:03
Put { braces } around the case statement code. You don't use hwndButton anywhere else in your code, so the compiler will now be happy. Whether you'll be happy tomorrow is however not so likely, creating a button every single time you paint is quite unusual. This is normally done in the message handler for WM_CREATE so it is only done once. And you normally need a global variable so you can reference the button later. — Hans Passant, Sep 09 '19 at 22:03
Don't create buttons in response to `WM_PAINT`. Add a new case for `WM_CREATE:`, and move `HWND hwndButton = CreateWindow` in there. — Barmak Shemirani, Sep 09 '19 at 22:23

Jeffreys · Answer 1 · 2019-09-10T03:31:34.480

Add the declaration of HWND hwndButton, move CreateWindow to WM_CREATE.Besides, move the TCHAR greeting[] out of WndProc()

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <tchar.h>

// Global variables

// The main window class name.
static TCHAR szWindowClass[] = _T("DesktopApp");

// The string that appears in the application's title bar.
static TCHAR szTitle[] = _T("WIndows Application test");

TCHAR greeting[] = _T("Hey Guys, this is my first Visual Studio desktop application, it has 158 lines of code!!!!!");

HINSTANCE hInst;
HWND hwndButton; // add here

// Forward declarations of functions included in this code module:
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int CALLBACK WinMain(
    _In_ HINSTANCE hInstance,
    _In_ HINSTANCE hPrevInstance,
    _In_ LPSTR     lpCmdLine,
    _In_ int       nCmdShow
)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = szWindowClass;
    wcex.hIconSm = LoadIcon(wcex.hInstance, IDI_APPLICATION);

    if (!RegisterClassEx(&wcex))
    {
        MessageBox(NULL,
            _T("Call to RegisterClassEx failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // Store instance handle in our global variable
    hInst = hInstance;

    // The parameters to CreateWindow explained:
    // szWindowClass: the name of the application
    // szTitle: the text that appears in the title bar
    // WS_OVERLAPPEDWINDOW: the type of window to create
    // CW_USEDEFAULT, CW_USEDEFAULT: initial position (x, y)
    // 500, 100: initial size (width, length)
    // NULL: the parent of this window
    // NULL: this application does not have a menu bar
    // hInstance: the first parameter from WinMain
    // NULL: not used in this application
    HWND hWnd = CreateWindow(
        szWindowClass,
        szTitle,
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT,
        600, 400,
        NULL,
        NULL,
        hInstance,
        NULL
    );

    if (!hWnd)
    {
        MessageBox(NULL,
            _T("Call to CreateWindow failed!"),
            _T("Windows Desktop Guided Tour"),
            NULL);

        return 1;
    }

    // The parameters to ShowWindow explained:
    // hWnd: the value returned from CreateWindow
    // nCmdShow: the fourth parameter from WinMain
    ShowWindow(hWnd,nCmdShow);
    UpdateWindow(hWnd);

    // Main message loop:
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}

//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_PAINT    - Paint the main window
//  WM_DESTROY  - post a quit message and return
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    PAINTSTRUCT ps;
    HDC hdc；

    switch (message)
    {
    case WM_CREATE:
        hwndButton = CreateWindowW(
            L"BUTTON",  // Predefined class; Unicode assumed 
            L"OK",      // Button text 
            WS_TABSTOP | WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON,  // Styles 
            10,         // x position 
            10,         // y position 
            100,        // Button width
            100,        // Button height
            hWnd,     // Parent window
            NULL,       // No menu.
            (HINSTANCE)GetWindowLong(hWnd, GWL_HINSTANCE),
            NULL);      // Pointer not needed.
         break;
    case WM_PAINT:
        hdc = BeginPaint(hWnd, &ps);

        // Here your application is laid out.
        // For this introduction, we just print out "Hello, Windows desktop!"
        // in the top left corner.
        TextOut(hdc, 5, 5, greeting, _tcslen(greeting));
        // End application-specific layout section.
        EndPaint(hWnd, &ps);
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

(1) This is nearly useless without explaining what you've changed and (2) changing `WM_PAINT` to `WM_CREATE` while *still calling `BeginPaint()` and `EndPaint()`* is totally wrong — Ben Voigt, Sep 10 '19 at 02:13
@Ben (1) I said it in the code comment. (2) Thanks for your remind — Jeffreys, Sep 10 '19 at 02:57

How to fix "initialization of 'hwndButton' is skipped by 'case' label" and hwndButton' is skipped by 'default' label"

1 Answers1