c++ - 在 LPSTR 文件路径中用双反斜杠或正斜杠替换反斜杠

Question

我正在尝试向 WIN32 API 发送消息以打开 WAV 文件。我可以通过将 LPARAM 参数设置为 L"C:/path/file.wav"来完成此操作，效果非常好!但是，我一直在尝试使用对话框生成文件路径的字符串。 OpenFileDialog 函数可以将选定的文件路径作为 LPSTR 数据类型返回，这听起来很完美!但是，此文件路径被识别为 Windows 文件路径，因此由反斜杠组成。由于这些反斜杠没有被转义或替换为正斜杠，编译器开始因格式不正确的通用字符名称而报错。因此，将 LPSTR 文件路径中的所有\替换为\或/似乎微不足道。我一直在尝试通过多种方式来做到这一点，但似乎没有任何效果。

wchar_t* SelectAudioFile(HWND windowHandle) {
    OPENFILENAME ofn;      // common dialog box structure
    char szFile[260];      // buffer for file name

    // Initialize OPENFILENAME
    ZeroMemory(&ofn, sizeof(ofn));
    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = windowHandle;
    ofn.lpstrFile = (LPWSTR)szFile;

    ofn.lpstrFile[0] = '\0';
    ofn.nMaxFile = sizeof(szFile);

    ofn.lpstrFilter = L"Waveform Audio File Format (*.wav)\0*.wav\0";

    ofn.nFilterIndex = 1;
    ofn.lpstrFileTitle = NULL;
    ofn.nMaxFileTitle = 0;
    ofn.lpstrInitialDir = NULL;
    ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

    // Display the Open dialog box.

    if (GetOpenFileName(&ofn)==TRUE) {
        CreateFile(ofn.lpstrFile,
            GENERIC_READ,
            0,
            (LPSECURITY_ATTRIBUTES) NULL,
            OPEN_EXISTING,
            FILE_ATTRIBUTE_NORMAL,
            (HANDLE) NULL);
        MessageBox(windowHandle,ofn.lpstrFile,0,0);
    }

     //Here the backslash should be escaped or replaced.

    const wchar_t * currentPath = ofn.lpstrFile; //This is a LPSTR 
    wchar_t * newPath;
    int filePathLength = sizeof(currentPath);

    for (int i=0; i < filePathLength; i++) {
        if (currentPath[i] == "\\") {
            newPath[i] = "\\\\";
        } else {
            newPath[i] = filePath[i];
        }
    }
    return newPath;


}

下一行会发布一条消息，告诉它打开路径中的某个文件

PostMessageW(hwnd, WMA_OPEN, 0, (LPARAM)SelectAudioFile(hwnd)); 

因此用静态文件路径替换 LPARAM 是可行的!

我应该如何替换文件路径中的反斜杠？

感谢一百万次!

Answer 1

你的代码有几个问题:

1. 您错误地混合了 Ansi 和 Unicode。

2. 您正在返回一个指向您尚未为其分配任何内存的本地缓冲区的指针。

3. 您正在使用 PostMessage() 异步发布本地缓冲区，该缓冲区可能会超出范围并在窗口处理消息之前变得无效。

4. 即使 GetOpenFileName() 失败或被取消，您仍要发布消息。

试试这个:

bool SelectAudioFile(HWND windowHandle, wchar_t *audioFile, int maxAudioFile)
{
    OPENFILENAMEW ofn = {0};

    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = windowHandle;
    ofn.lpstrFile = audioFile;
    ofn.nMaxFile = maxAudioFile;
    ofn.lpstrFilter = L"Waveform Audio File Format (*.wav)\0*.wav\0";
    ofn.nFilterIndex = 1;
    ofn.lpstrFileTitle = NULL;
    ofn.nMaxFileTitle = 0;
    ofn.lpstrInitialDir = NULL;
    ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

    if (GetOpenFileNameW(&ofn))
    {
        MessageBoxW(windowHandle, audioFile, 0, 0);
        return true;
    }

    return false;
}

wchar_t szAudioFile[MAX_PATH+1] = {0};
if (SelectAudioFile(hwnd, szAudioFile, MAX_PATH))
    SendMessageW(hwnd, WMA_OPEN, 0, (LPARAM)szAudioFile); 

或者:

#include <string>

std::wstring SelectAudioFile(HWND windowHandle)
{
    OPENFILENAMEW ofn = {0};
    wchar_t szFile[MAX_PATH+1] = {0};

    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = windowHandle;
    ofn.lpstrFile = szFile;
    ofn.nMaxFile = MAX_PATH;
    ofn.lpstrFilter = L"Waveform Audio File Format (*.wav)\0*.wav\0";
    ofn.nFilterIndex = 1;
    ofn.lpstrFileTitle = NULL;
    ofn.nMaxFileTitle = 0;
    ofn.lpstrInitialDir = NULL;
    ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

    if (GetOpenFileNameW(&ofn))
        MessageBoxW(windowHandle, szFile, 0, 0);

    return szFile;
}

std::wstring audioFile = SelectAudioFile(hwnd);
if (audioFile.length() > 0)
    SendMessageW(hwnd, WMA_OPEN, 0, (LPARAM)audioFile.c_str());