如何读取文本文件并将其显示在 win 32 unicode 字符集中的编辑控件上？

Posted 2023-02-21

【中文标题】如何读取文本文件并将其显示在 win 32 unicode 字符集中的编辑控件上？

【英文标题】：how to read text file and show it on edit control in win 32 unicode character set?

【发布时间】：2016-01-08 04:56:27

【问题描述】：

我一直在制作一个程序，通过单击按钮从文本文件中读取文本并将其显示在编辑控件上。单击按钮时，将打开对话框以选择文本文件并单击确定，它应该显示在编辑控件上，但我没有以正确的格式获取文本。 这是输出：output image from visual studio

#include <windows.h>
const wchar_t g_szClassName[] =  L"myWindowClass" ;
#define IDC_MAIN_EDIT 101
#define IDC_MAIN_BUTTON 102
#define IDC_MAIN_BUTTON1 103
BOOL LoadTextFileToEdit(HWND hEdit, LPTSTR pszFileName)

HANDLE hFile;
BOOL bSuccess = FALSE;
hFile = CreateFile(pszFileName, GENERIC_READ, FILE_SHARE_READ, NULL,
    OPEN_EXISTING, 0, NULL);
if (hFile != INVALID_HANDLE_VALUE)

    DWORD dwFileSize;
    dwFileSize = GetFileSize(hFile, NULL);
    if (dwFileSize != 0xFFFFFFFF)
    
        wchar_t* pszFileText;
        pszFileText = (wchar_t*)GlobalAlloc(GPTR, dwFileSize + 1);

        if (pszFileText != NULL)
        
            DWORD dwRead;
            if (ReadFile(hFile, (LPVOID)pszFileText,  dwFileSize, &dwRead, NULL))                 
            
                pszFileText[dwFileSize] =  0 ; // Add null terminator

                if (SetWindowText(hEdit, (LPCWSTR)pszFileText))
                    bSuccess = TRUE; // It worked!
            
            GlobalFree(pszFileText);
        
    
    CloseHandle(hFile);

return bSuccess;


// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)

switch (msg)

case WM_CREATE:

    HFONT hfont;
    HWND hedit,button,btnsave;
    hedit = CreateWindowEx(WS_EX_CLIENTEDGE, L"EDIT", L"My Own Window",   WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_AUTOVSCROLL | ES_MULTILINE
        , CW_USEDEFAULT, CW_USEDEFAULT, 100, 100, hwnd, (HMENU)IDC_MAIN_EDIT, GetModuleHandle(NULL), NULL);
    button = CreateWindowEx(WS_EX_CLIENTEDGE, L"BUTTON", L"Open File", WS_CHILD | WS_VISIBLE|WS_BORDER|WS_TABSTOP
        ,CW_USEDEFAULT, CW_USEDEFAULT, 50, 20, hwnd, (HMENU)IDC_MAIN_BUTTON, GetModuleHandle(NULL), NULL);
    btnsave = CreateWindowEx(WS_EX_CLIENTEDGE, L"BUTTON", L"Save File", WS_CHILD | WS_VISIBLE | WS_EX_STATICEDGE|WS_TABSTOP
        , CW_USEDEFAULT, CW_USEDEFAULT, 50, 20, hwnd, (HMENU)IDC_MAIN_BUTTON1, GetModuleHandle(NULL), NULL);
    if (hedit == NULL)
    
        MessageBox(NULL, L"Could not create edit box", L"Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    
    hfont = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
    SendMessage(hedit, WM_SETFONT, (WPARAM)hfont, MAKELPARAM(FALSE, 0));
    //SetWindowText(button, L"Open File");

    //SetWindowText(btnsave, L"Save File");

break;
case WM_COMMAND:
    switch (LOWORD(wParam))
    
    case IDC_MAIN_BUTTON:
    
        OPENFILENAME ofn;
        wchar_t szFileName[MAX_PATH] = L"";
        ZeroMemory(&ofn, sizeof(ofn));
        ofn.lStructSize = sizeof(ofn); // SEE NOTE BELOW
        ofn.hwndOwner = hwnd;
        ofn.lpstrFilter = L"Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0";
        ofn.lpstrFile = szFileName;
        ofn.nMaxFile = MAX_PATH;
        ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST | OFN_HIDEREADONLY;
        ofn.lpstrDefExt = L"txt";
        if (GetOpenFileName(&ofn))
        
            // Do something usefull with the filename stored in szFileName
            HWND hedit;
            hedit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
            LoadTextFileToEdit(hedit, szFileName);
        
    
    break;
    case IDC_MAIN_BUTTON1:
    
        OPENFILENAME ofn;
        wchar_t szFileName[MAX_PATH] = L"";
        ZeroMemory(&ofn, sizeof(ofn));
        ofn.lStructSize = sizeof(ofn); // SEE NOTE BELOW
        ofn.hwndOwner = hwnd;
        ofn.lpstrFilter = L"Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0";
        ofn.lpstrFile = szFileName;
        ofn.nMaxFile = MAX_PATH;
        ofn.Flags = OFN_EXPLORER | OFN_PATHMUSTEXIST | OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT;
        ofn.lpstrDefExt = L"txt";
        if (GetOpenFileName(&ofn))
        
            // Do something usefull with the filename stored in szFileName
            HWND hedit;
            hedit = GetDlgItem(hwnd, IDC_MAIN_EDIT);

        
    
    break;
    default:
        break;
    
break;
case WM_SIZE:

    HWND hEdit,button,btnsave;
    RECT rcClient;
    GetClientRect(hwnd, &rcClient);
    hEdit = GetDlgItem(hwnd, IDC_MAIN_EDIT);
    button = GetDlgItem(hwnd, IDC_MAIN_BUTTON);
    btnsave = GetDlgItem(hwnd, IDC_MAIN_BUTTON1);
    SetWindowPos(hEdit, NULL, 0, 0, rcClient.right, rcClient.bottom-120, SWP_NOZORDER);
    SetWindowPos(button, NULL, rcClient.right-200, rcClient.bottom-30, 70, 30, SWP_NOZORDER);
    SetWindowPos(btnsave, NULL, rcClient.right - 100, rcClient.bottom - 30, 70, 30, SWP_NOZORDER);

break;
case WM_CLOSE:
    DestroyWindow(hwnd);
    break;
case WM_DESTROY:
    PostQuitMessage(0);
    break;
default:
    return DefWindowProc(hwnd, msg, wParam, lParam);

return 0;

int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hPrevInstance, LPSTR  lpCmdLine, int nCmdShow)

WNDCLASSEX wc;
HWND hwnd;
MSG msg;

//step 1: registering the window class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hinstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

if (!RegisterClassEx(&wc))

    MessageBox(NULL, L"Window Registration failed", L"Error!", MB_ICONEXCLAMATION | MB_OK);
    return 0;


//step 2: Creating the Window
hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,
    g_szClassName, L"The title of my window", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 500, 300,
    NULL, NULL, hinstance, NULL);

if (hwnd == NULL)

    MessageBox(NULL, L"Window Registration failed", L"Error!", MB_ICONEXCLAMATION | MB_OK);
    return 0;

ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);

//Step-3: the message loop
while (GetMessage(&msg, NULL, 0, 0)>0)

    TranslateMessage(&msg);
    DispatchMessage(&msg);

return msg.wParam;

【问题讨论】：

文件实际上是否包含 Unicode 文本？您可能应该调用 MultiByteToWideChar 并传递与文件内容匹配的代码页标识符。

另外，你不应该有那么多演员表。

它是一个普通的文本文件@BenVoigt，你能告诉我是什么问题并提供解决方案吗？

pszFileText[dwFileSize] = 0 行是缓冲区溢出。您正在破坏内存（并且未能正确终止字符串）。

我已经尝试过 pszFileText[dwFileSize] = '\0' 和 pszFileText[dwFileSize] = L'\0' 但同样的问题，但现在我得到了解决方案并发布了它

【参考方案1】：

我得到了我的问题的答案。实际上在 unicode 宽字符串中，一个字符是 2 个字节，所以我们需要分配两倍的内存。所以替换：

pszFileText = (wchar_t*)GlobalAlloc(GPTR, dwFileSize + 1);

与

pszFileText = (wchar_t*)GlobalAlloc(GPTR, 2*(dwFileSize + 1));

和

if (ReadFile(hFile, (LPVOID)pszFileText,  dwFileSize, &dwRead, NULL)) 

与

if (ReadFile(hFile, (LPVOID)pszFileText,  2*(dwFileSize+1), &dwRead, NULL))