mfc http协议上传超过4G的文件 完整代码

MFC框架下的HTTP上传文件大小受限于HTTP协议和操作系统的限制，一般最大只能上传2G左右的文件。如果要上传超过4G的文件，可以使用分片上传的方式，将大文件分成多个小文件，分别上传并合并。以下是一个简单的示例代码，仅供参考：

void CMyHttpDlg::OnUpload()
{
    CFileDialog dlg(TRUE, NULL, NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, _T("All Files (*.*)|*.*||"), NULL);
    if (dlg.DoModal() == IDOK)
    {
        CString strFilePath = dlg.GetPathName();
        CString strFileName = dlg.GetFileName();
        CString strBoundary = _T("----MyBoundary");
        CString strHeader;
        strHeader.Format(_T("Content-Type: multipart/form-data; boundary=%s"), strBoundary);
        CString strData;
        strData.Format(_T("--%s\r\nContent-Disposition: form-data; name=\"file\"; filename=\"%s\"\r\nContent-Type: application/octet-stream\r\n\r\n"), strBoundary, strFileName);
        CFile file(strFilePath, CFile::modeRead | CFile::shareDenyNone);
        ULONGLONG dwFileSize = file.GetLength();
        ULONGLONG dwBytesSent = 0;
        DWORD dwChunkSize = 1024 * 1024; // 每次上传1MB数据
        char *pChunkData = new char[dwChunkSize];
        DWORD dwBytesRead = 0;
        CInternetSession session;
        CHttpConnection *pConnection = session.GetHttpConnection(_T("www.example.com"), INTERNET_DEFAULT_HTTP_PORT, NULL, NULL);
        CString strFormData = strData;
        while (dwBytesSent < dwFileSize)
        {
            DWORD dwBytesToRead = min(dwChunkSize, dwFileSize - dwBytesSent);
            file.Read(pChunkData, dwBytesToRead);
            strFormData.Append(pChunkData, dwBytesToRead);
            dwBytesSent += dwBytesToRead;
            if (dwBytesSent == dwFileSize)
            {
                strFormData.AppendFormat(_T("\r\n--%s--\r\n"), strBoundary);
            }
            else
            {
                strFormData.AppendFormat(_T("\r\n--%s\r\nContent-Disposition: form-data; name=\"file\"; filename=\"%s\"\r\nContent-Type: application/octet-stream\r\n\r\n"), strBoundary, strFileName);
            }
            if (dwBytesSent % dwChunkSize == 0 || dwBytesSent == dwFileSize)
            {
                CHttpFile *pFile = pConnection->OpenRequest(CHttpConnection::HTTP_VERB_POST, _T("upload.php"), NULL, 1, NULL, NULL, INTERNET_FLAG_RELOAD);
                pFile->AddRequestHeaders(strHeader);
                pFile->SendRequest(strFormData, strFormData.GetLength());
                char szResponse[1024];
                while (pFile->Read(szResponse, 1024) > 0)
                {
                    // 处理服务器响应
                }
                pFile->Close();
                delete pFile;
                strFormData = strData;
            }
        }
        file.Close();
        delete[] pChunkData;
        pConnection->Close();
        delete pConnection;
    }
}

需要注意的是，上传超过4G的文件可能需要很长时间，需要在客户端和服务器端都进行相关设置来避免连接超时等问题。此外，为了保证上传的数据完整性，还需要在服务器端进行数据校验和错误处理。