使用 Wininet 上传文件时如何添加正确的 Content-Type？ （HTTP 放置）

Posted 2023-02-16

【中文标题】使用 Wininet 上传文件时如何添加正确的 Content-Type？ （HTTP 放置）

【英文标题】：How to add correct Content-Type when uploading file with Wininet? (HTTP PUT)

【发布时间】：2015-09-30 04:17:02

【问题描述】：

我正在将带有Wininet 的文件上传到带有HTTP PUT 的Sharepoint 服务器。然而，即使我指定了一个带有.xlsx 扩展名的文件名，我在Sharepoint 服务器上得到了一个名为.xlsx 的文件，但是在下载它时，它得到了一个.zip 扩展名。此外，在 Sharepoint 上，文件旁边没有 Excel 小图标，而是一个更通用的图标。我已经尝试了使用 HttpAddRequestHeaders 和 HttpSendRequest 设置 Content-type（“mime-type”）的所有组合，我可以想出。

以下代码上传文件，但 Sharepoint 获取的内容类型错误：

static int upload_file_to_sharepoint(LPCSTR filename, LPCSTR server, LPCSTR location)

    HINTERNET hIntrn = InternetOpenA(
        "magic", 
         INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY,
         NULL,
         NULL,
         0
    );
    if (!hIntrn)
        return printf("No Internet connection: %li.\n", GetLastError());

    HINTERNET hConn = InternetConnectA(
        hIntrn, 
        server,
        INTERNET_DEFAULT_HTTPS_PORT,
        NULL,
        NULL,
        INTERNET_SERVICE_HTTP,
        0,
        NULL
    );

    if (!hConn)
        return printf("Connection to update server failed: %li.\n", GetLastError());

    DWORD dwOpenRequestFlags =
        INTERNET_FLAG_KEEP_CONNECTION |
        INTERNET_FLAG_NO_COOKIES |
        INTERNET_FLAG_NO_CACHE_WRITE |
        INTERNET_FLAG_NO_UI |
        INTERNET_FLAG_RELOAD;

    PCSTR rgpszAcceptTypes[] = 
        "text/*",
        "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        NULL
    ;

    HINTERNET hReq = HttpOpenRequestA(
        hConn,
        "PUT",
        location,
        "HTTP/1.1",
        NULL,
        rgpszAcceptTypes,
        dwOpenRequestFlags,
        NULL
    );


    HANDLE hFile = CreateFileA(
        filename,
        GENERIC_READ,
        FILE_SHARE_READ,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL
    );

    if (NULL == hFile) 
        ExitProcess(1);
    

    HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);
    if (NULL == hMap) 
        ExitProcess(1);
    

    LPVOID lpvFile = MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, 0);

    DWORD dwFileSize = GetFileSize(hFile, NULL);

    CHAR mimetype[1024];
    sprintf(
        mimetype,
        "Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
    //"Content-Type: application/vnd.ms-excel\r\n"
    );

    if (!HttpAddRequestHeadersA(hReq, mimetype, -1, HTTP_ADDREQ_FLAG_REPLACE)) 
        printf("Failed adding mime header\n");
    

    if (!HttpSendRequestA(
        hReq,
        NULL,// "Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        0, //-1,
        lpvFile,
        dwFileSize)) 
        printf("HttpSendRequest failed: %li.\n", GetLastError());
    

    UnmapViewOfFile(lpvFile);
    CloseHandle(hMap);
    CloseHandle(hFile);

    printf("Uploaded file to http://%s%s\n", server, location);

    return 0;

我用 Fiddler 捕获了标题，得到了这个：

PUT http://x.com/CENSORED/a.xslx HTTP/1.1
Accept: text/*, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Content-Disposition: attachment; filename="a.xlsx"
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
User-Agent: magic
Host: censored
Content-Length: 772303
Connection: Keep-Alive
Pragma: no-cache


HTTP/1.1 200 OK
Cache-Control: private,max-age=0
Content-Length: 0
Expires: Tue, 15 Sep 2015 08:43:16 GMT
Last-Modified: Wed, 30 Sep 2015 08:43:16 GMT
ETag: "0DC262D0-83AE-489A-90CD-EB23B284A3B3,14"
Server: Microsoft-IIS/7.5
SPRequestGuid: 6aba173e-41db-4b14-b7df-7714c54db282
X-SharePointHealthScore: 0
ResourceTag: rt:0DC262D0-83AE-489A-90CD-EB23B284A3B3@00000000014
Public-Extension: http://schemas.microsoft.com/repl-2
X-Powered-By: ASP.NET
MicrosoftSharePointTeamServices: 14.0.0.7145
X-MS-InvokeApp: 1; RequireReadOnly
ServerName: Xcensored
Date: Wed, 30 Sep 2015 08:43:16 GMT

【问题讨论】：

您似乎没有向服务器提供文件名，也许与它有关？

@JonathanPotter，这是在HttpOpenRequestA( hConn, "PUT", location, 中完成的AFAIK，其中location 是URL 中指出文件名的部分。实际上在文件列表中的服务器上称为“output.xslx”，但下载时我得到“output.zip”。我也可以在浏览器中上传一个文件，然后我得到 两个 文件，称为 output.xlsx。后者作为 xlsx 文件下载。

我认为内容类型应该是application/vnd.ms-excel，因为你已经尝试过了，但也可以尝试添加Content-Disposition: attachment; filename="filename.xlsx"

那行不通。它运行时没有运行时警告但没有雪茄： if (!HttpAddRequestHeadersA( hReq, "Content-Disposition: attachment; filename=\"a.xlsx\"", (DWORD)-1, HTTP_ADDREQ_FLAG_REPLACE | HTTP_ADDREQ_FLAG_ADD )) printf("Failed添加 mime 类型的标题\n"); if (!HttpAddRequestHeadersA( hReq, "Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", (DWORD)-1, HTTP_ADDREQ_FLAG_REPLACE | HTTP_ADDREQ_FLAG_ADD )) printf("@JonathanPotter");

【参考方案1】：

因此，如果您将文件上传为 .xlsx 而不是 .xslx 会有所帮助...

代码现在可以运行，看起来像这样，不需要特殊的标头，这与我在网上找到的其他示例一致：

static int upload_file_to_sharepoint(LPCSTR filename, LPCSTR server, LPCSTR location)

    HINTERNET hIntrn = InternetOpenA(
        "magic", 
         INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY,
         NULL,
         NULL,
         0
    );
    if (!hIntrn)
        return printf("No Internet connection: %li.\n", GetLastError());

    HINTERNET hConn = InternetConnectA(
        hIntrn, 
        server,
        INTERNET_DEFAULT_HTTPS_PORT,
        NULL,
        NULL,
        INTERNET_SERVICE_HTTP,
        0,
        NULL
    );

    if (!hConn)
        return printf("Connection to update server failed: %li.\n", GetLastError());

    DWORD dwOpenRequestFlags =
        INTERNET_FLAG_KEEP_CONNECTION |
        INTERNET_FLAG_NO_COOKIES |
        INTERNET_FLAG_NO_CACHE_WRITE |
        INTERNET_FLAG_NO_UI |
        INTERNET_FLAG_RELOAD;

    HINTERNET hReq = HttpOpenRequestA(
        hConn,
        "PUT",
        location,
        "HTTP/1.1",
        NULL,
        NULL,
        dwOpenRequestFlags,
        NULL
    );


    HANDLE hFile = CreateFileA(
        filename,
        GENERIC_READ,
        FILE_SHARE_READ,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL
    );

    if (NULL == hFile) 
        ExitProcess(1);
    

    HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0, 0, NULL);
    if (NULL == hMap) 
        ExitProcess(1);
    

    LPVOID lpvFile = MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, 0);

    DWORD dwFileSize = GetFileSize(hFile, NULL);    

    if (!HttpSendRequestA(
        hReq,
        NULL,
        0,
        lpvFile,
        dwFileSize)) 
        printf("HttpSendRequest failed: %li.\n", GetLastError());
    

    UnmapViewOfFile(lpvFile);
    CloseHandle(hMap);
    CloseHandle(hFile);

    printf("Uploaded file to http://%s%s\n", server, location);

    return 0;