What changes have to be done to make this Windows textbox from 2011, work now, in 2019?

问题

I tried compiling the code in this question from 2011 about making a C++ Textbox...

#include <windows.h>

#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='x86' publicKeyToken='6595b64144ccf1df' language='*'\"")

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR nCmdLine, int nCmdShow)
{
    LPTSTR windowClass = TEXT("WinApp");
    LPTSTR windowTitle = TEXT("Windows Application");
    WNDCLASSEX wcex;

    wcex.cbClsExtra = 0;
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.cbWndExtra = 0;
    wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hInstance = hInstance;
    wcex.lpfnWndProc = WndProc;
    wcex.lpszClassName = windowClass;
    wcex.lpszMenuName = NULL;
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    if (!RegisterClassEx(&wcex))
    {
        MessageBox(NULL, TEXT("RegisterClassEx Failed!"), TEXT("Error"), MB_ICONERROR);
        return EXIT_FAILURE;
    }

    HWND hWnd;

    if (!(hWnd = CreateWindow(windowClass, windowTitle, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL)))
    {
        MessageBox(NULL, TEXT("CreateWindow Failed!"), TEXT("Error"), MB_ICONERROR);
        return EXIT_FAILURE;
    }

    HWND hWndEdit = CreateWindow(TEXT("Edit"), TEXT("test"), WS_CHILD | WS_VISIBLE | WS_BORDER, 100, 20, 140, 20, hWnd, NULL, NULL, NULL);

    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    MSG msg;

    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return EXIT_SUCCESS;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_DESTROY:
        PostQuitMessage(EXIT_SUCCESS);
    default:
        return DefWindowProc(hWnd, msg, wParam, lParam);
    }
    return FALSE;
}

But trying to build it in Visual Studio 2019, I get errors about being unable to convert a "t_char" to a "LPTSTR".

So, how do I update the code to work? And is it possible without Including any other files?

回答1:

Use LPCTSTR instead of LPTSTR:

LPCTSTR windowClass = TEXT("WinApp");
LPCTSTR windowTitle = TEXT("Windows Application");

LPTSTR is TCHAR *

LPCTSTR is const TCHAR *

TEXT("literal") produces a const TCHAR [].

A string literal is const data. Since C++11, you can no longer assign a string literal to a pointer-to-non-const.

回答2:

Get out of the TCHAR business entirely. Those TEXT macros are for cross-compiling with code meant to run on Windows 9x.

Changes these lines:

LPTSTR windowClass = TEXT("WinApp");
LPTSTR windowTitle = TEXT("Windows Application");

To this:

LPCWSTR windowClass = L"WinApp";
LPCWSTR windowTitle = L"Windows Application";

And then all subsequent usages of TEXT macros like in the following:

MessageBox(NULL, TEXT("RegisterClassEx Failed!"), TEXT("Error"), MB_ICONERROR);

To just be wide strings:

MessageBox(NULL, L"RegisterClassEx Failed!", L"Error", MB_ICONERROR);

来源：https://stackoverflow.com/questions/56307075/what-changes-have-to-be-done-to-make-this-windows-textbox-from-2011-work-now-i

标签

c++

winapi

visual-studio-2019