C++ WinAPI。列表框中显示错误的文本

Question

我的任务是创建一个程序来显示系统中所有 windows 的描述符列表。我得到这个输出：

可能是编码错误？

这是我的代码：

#include <windows.h>

ATOM RegMyWindowClass(HINSTANCE, LPCTSTR);
HWND hListBox;
HINSTANCE hin;

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    WCHAR str[255];
    if (GetWindowTextW(hwnd, str, 255)) {
        if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER)))
            SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
    }
    return 1;
}

LRESULT CALLBACK WndProc(
    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_LBUTTONUP:
        MessageBox(hWnd, TEXT("Вы кликнули!"), TEXT("событие"), 0);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);  
        break;
    case WM_CREATE:
        hListBox = CreateWindow("LISTBOX", "", WS_CHILD | WS_VISIBLE | LBS_NOTIFY | WS_VSCROLL,
            0, 0, 400, 400, hWnd, (HMENU)1111, hin, NULL);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,
    HINSTANCE         hPrevInstance,
    LPSTR             lpCmdLine,
    int               nCmdShow)
{
    LPCTSTR lpzClass = TEXT("My Window Class!");

    if (!RegMyWindowClass(hInstance, lpzClass))
        return 1;

    RECT screen_rect;
    GetWindowRect(GetDesktopWindow(), &screen_rect); 
    int x = screen_rect.right / 2 - 200;
    int y = screen_rect.bottom / 2 - 200;

    HWND hWnd = CreateWindow(lpzClass, TEXT("Window"),
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, x, y, 400, 400, NULL, NULL,
        hInstance, NULL);
    ShowWindow(hWnd, SW_SHOW);
    EnumWindows(&EnumWindowsProc, 0);
    if (!hWnd) return 2;

    MSG msg = { 0 };   
    int iGetOk = 0;   
    while ((iGetOk = GetMessage(&msg, NULL, 0, 0)) != 0)
    {
        if (iGetOk == -1) return 3;  
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;  
}

ATOM RegMyWindowClass(HINSTANCE hInst, LPCTSTR lpzClassName)
{
    WNDCLASS wcWindowClass = { 0 };
    wcWindowClass.lpfnWndProc = (WNDPROC)WndProc;
    wcWindowClass.style = CS_HREDRAW | CS_VREDRAW;
    wcWindowClass.hInstance = hInst;
    wcWindowClass.lpszClassName = lpzClassName;
    wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcWindowClass.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
    return RegisterClass(&wcWindowClass); 
}

有什么解决办法吗？

Answer 1

问题是您正在为 ANSI 编译项目，其中 TCHAR 是 CHAR 的别名，因此正在创建基于 ANSI 的列表框，但您正在将 Unicode 字符串发送到它。这就是您在输出中看到垃圾的原因。您需要将 ANSI 字符串发送到 ListBox，例如：

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER)))
        CHAR str[255] = {};
        if (GetWindowTextA(hwnd, str, 255)) {
            SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
        }
    }
    return TRUE;
}

或者：

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER))) {
        CHAR str[255] = {};
        if (IsWindowUnicode(hwnd)) {
            WCHAR wstr[255] = {}; 
            int len = GetWindowTextW(hwnd, wstr, 255);
            if (len) {
                len = WideCharToMultiByte(CP_ACP, 0, wstr, len+1, str, 255, NULL, NULL);
            }
            if (!len) {
                return TRUE;
            }
        }
        else if (!GetWindowTextA(hwnd, str, 255)) {
            return TRUE;
        }
        SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
    }
    return TRUE;
}

也就是说，您正在混合使用 ANSI、Unicode 和 TCHAR API。你需要选择 1 API 风格并坚持使用它，不要混合使用它们（除非你绝对必须这样做）。

由于您显示的大部分代码已经使用 TCHAR，因此您可以对所有内容使用 TCHAR（不过，您确实不应该这样做，因为 TCHAR 是意味着与 Win9x/ME 的向后兼容性，后者不再被使用，并且仅旨在帮助人们将他们的代码迁移到 Unicode。现代代码根本不应该使用 TCHAR：

#include <windows.h>

ATOM RegMyWindowClass(HINSTANCE, LPCTSTR);
HWND hListBox;
HINSTANCE hin;

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER))) {
        TCHAR str[255];
        if (GetWindowText(hwnd, str, 255)) {
            SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
        }
    }
    return TRUE;
}

LRESULT CALLBACK WndProc(
    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_LBUTTONUP:
        // this is one case where it doesn't make sense to use TCHAR
        MessageBoxW(hWnd, L"Вы кликнули!", L"событие", 0);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);  
        break;
    case WM_CREATE:
        hListBox = CreateWindow(TEXT("LISTBOX"), TEXT(""), WS_CHILD | WS_VISIBLE | LBS_NOTIFY | WS_VSCROLL,
            0, 0, 400, 400, hWnd, (HMENU)1111, hin, NULL);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,
    HINSTANCE         hPrevInstance,
    LPSTR             lpCmdLine,
    int               nCmdShow)
{
    LPCTSTR lpzClass = TEXT("My Window Class!");

    if (!RegMyWindowClass(hInstance, lpzClass))
        return 1;

    RECT screen_rect;
    GetWindowRect(GetDesktopWindow(), &screen_rect); 
    int x = screen_rect.right / 2 - 200;
    int y = screen_rect.bottom / 2 - 200;

    HWND hWnd = CreateWindow(lpzClass, TEXT("Window"),
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, x, y, 400, 400, NULL, NULL,
        hInstance, NULL);
    ShowWindow(hWnd, SW_SHOW);
    EnumWindows(&EnumWindowsProc, 0);
    if (!hWnd) return 2;

    MSG msg = { 0 };   
    int iGetOk = 0;   
    while ((iGetOk = GetMessage(&msg, NULL, 0, 0)) != 0)
    {
        if (iGetOk == -1) return 3;  
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;  
}

ATOM RegMyWindowClass(HINSTANCE hInst, LPCTSTR lpzClassName)
{
    WNDCLASS wcWindowClass = { 0 };
    wcWindowClass.lpfnWndProc = &WndProc;
    wcWindowClass.style = CS_HREDRAW | CS_VREDRAW;
    wcWindowClass.hInstance = hInst;
    wcWindowClass.lpszClassName = lpzClassName;
    wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcWindowClass.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
    return RegisterClass(&wcWindowClass); 
}

否则，对所有内容使用 Unicode：

#include <windows.h>

ATOM RegMyWindowClass(HINSTANCE, LPCWSTR);
HWND hListBox;
HINSTANCE hin;

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER))) {
        WCHAR str[255];
        if (GetWindowTextW(hwnd, str, 255)) {
            SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
        }
    }
    return TRUE;
}

LRESULT CALLBACK WndProc(
    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_LBUTTONUP:
        MessageBoxW(hWnd, L"Вы кликнули!", L"событие", 0);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);  
        break;
    case WM_CREATE:
        hListBox = CreateWindowW(L"LISTBOX", L"", WS_CHILD | WS_VISIBLE | LBS_NOTIFY | WS_VSCROLL,
            0, 0, 400, 400, hWnd, (HMENU)1111, hin, NULL);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,
    HINSTANCE         hPrevInstance,
    LPSTR             lpCmdLine,
    int               nCmdShow)
{
    LPCWSTR lpzClass = L"My Window Class!";

    if (!RegMyWindowClass(hInstance, lpzClass))
        return 1;

    RECT screen_rect;
    GetWindowRect(GetDesktopWindow(), &screen_rect); 
    int x = screen_rect.right / 2 - 200;
    int y = screen_rect.bottom / 2 - 200;

    HWND hWnd = CreateWindowW(lpzClass, L"Window",
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, x, y, 400, 400, NULL, NULL,
        hInstance, NULL);
    ShowWindow(hWnd, SW_SHOW);
    EnumWindows(&EnumWindowsProc, 0);
    if (!hWnd) return 2;

    MSG msg = { 0 };   
    int iGetOk = 0;   
    while ((iGetOk = GetMessage(&msg, NULL, 0, 0)) != 0)
    {
        if (iGetOk == -1) return 3;  
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;  
}

ATOM RegMyWindowClass(HINSTANCE hInst, LPCWSTR lpzClassName)
{
    WNDCLASSW wcWindowClass = { 0 };
    wcWindowClass.lpfnWndProc = &WndProc;
    wcWindowClass.style = CS_HREDRAW | CS_VREDRAW;
    wcWindowClass.hInstance = hInst;
    wcWindowClass.lpszClassName = lpzClassName;
    wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcWindowClass.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
    return RegisterClassW(&wcWindowClass); 
}

或者，如果您需要与项目中其他地方的现有代码逻辑保持兼容性，则一切都坚持使用 ANSI：

#include <windows.h>

ATOM RegMyWindowClass(HINSTANCE, LPCSTR);
HWND hListBox;
HINSTANCE hin;

BOOL CALLBACK EnumWindowsProc(HWND hwnd, LPARAM lParam)
{
    if (IsWindowVisible(hwnd) && (!GetWindow(hwnd, GW_OWNER))) {
        CHAR str[255];
        if (GetWindowTextA(hwnd, str, 255)) {
            SendMessage(hListBox, LB_ADDSTRING, 0, (LPARAM)str);
        }
    }
    return TRUE;
}

LRESULT CALLBACK WndProc(
    HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_LBUTTONUP:
        // this is one case where it doesn't make sense to use ANSI
        MessageBoxW(hWnd, L"Вы кликнули!", L"событие", 0);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);  
        break;
    case WM_CREATE:
        hListBox = CreateWindowA("LISTBOX", "", WS_CHILD | WS_VISIBLE | LBS_NOTIFY | WS_VSCROLL,
            0, 0, 400, 400, hWnd, (HMENU)1111, hin, NULL);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

int APIENTRY WinMain(HINSTANCE hInstance,
    HINSTANCE         hPrevInstance,
    LPSTR             lpCmdLine,
    int               nCmdShow)
{
    LPCSTR lpzClass = "My Window Class!";

    if (!RegMyWindowClass(hInstance, lpzClass))
        return 1;

    RECT screen_rect;
    GetWindowRect(GetDesktopWindow(), &screen_rect); 
    int x = screen_rect.right / 2 - 200;
    int y = screen_rect.bottom / 2 - 200;

    HWND hWnd = CreateWindowA(lpzClass, "Window",
        WS_OVERLAPPEDWINDOW | WS_VISIBLE, x, y, 400, 400, NULL, NULL,
        hInstance, NULL);
    ShowWindow(hWnd, SW_SHOW);
    EnumWindows(&EnumWindowsProc, 0);
    if (!hWnd) return 2;

    MSG msg = { 0 };   
    int iGetOk = 0;   
    while ((iGetOk = GetMessage(&msg, NULL, 0, 0)) != 0)
    {
        if (iGetOk == -1) return 3;  
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return msg.wParam;  
}

ATOM RegMyWindowClass(HINSTANCE hInst, LPCSTR lpzClassName)
{
    WNDCLASSA wcWindowClass = { 0 };
    wcWindowClass.lpfnWndProc = &WndProc;
    wcWindowClass.style = CS_HREDRAW | CS_VREDRAW;
    wcWindowClass.hInstance = hInst;
    wcWindowClass.lpszClassName = lpzClassName;
    wcWindowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcWindowClass.hbrBackground = (HBRUSH)COLOR_APPWORKSPACE;
    return RegisterClassA(&wcWindowClass); 
}

C++ WinAPI。列表框中显示错误的文本

C++ WinAPI. Wrong text display in the listbox

c++

winapi

sendmessage