Question

所以这与问题所发生的情况类似：FileWebRequest not returning what it should

我正在尝试使用URI / WebRequest下载文件，其想法是我们可以在FTP / Web / Local文件操作中使用该方法。

以下是代码：

var req = WebRequest.Create(uri);
var fileExt = Path.GetExtension(uri.AbsolutePath).ToUpper().Substring(1);

switch (fileExt)
{
    case "JPG":
    case "JPEG":
        req.ContentType = _mimeJpeg;
        break;

    case "PNG":
        req.ContentType = _mimePng;
        break;

    case "TIF":
    case "TIFF":
        req.ContentType = _mimeTiff;
        break;
}

req.Timeout = timeout;

//The GetResponse call actually makes the request
var resp = req.GetResponse();

//Check the content type of the response to make sure it is
//one of the formats we support
if (resp.ContentType != _mimeTiff)
{
    var contentType = resp.ContentType;
    resp.Close();
    throw new Exception(String.Format("The image at the URL you provided is in an unsupported format ({0}).  " + "Uploaded images must be in either JPEG, PNG, or TIFF formats.", contentType));
}

Microsoft自己的文档说Resp.ContentType的ContentType始终是“binary \ octet-stream”（找到here）。问题是，这会导致以后出现问题，因为我们期待一个图像文件（我们尝试使用此方法加载的文件类型是GIF，TIFF，JPEG等）。我们该怎么办？

修改的

特定错误发生在：

//Check the content type of the response to make sure it is
//one of the formats we support
if (resp.ContentType != _mimeTiff)
{
    var contentType = resp.ContentType;
    resp.Close();
    throw new Exception(String.Format("The image at the URL you provided is in an unsupported format ({0}).  " + "Uploaded images must be in either JPEG, PNG, or TIFF formats.", contentType));
}

因为我们一直在返回MIME类型的Application / Octet-Stream。

Answer 1

我做了一些额外的研究......显然这是微软提出的一个硬编码漏洞。

Here is the MSDN Article描述FileWebResponse.GetContentType ALWAYS返回二进制/八位字节流，然后进一步解释为Application / Octet-Stream。

FileWebRequest不返回本地文件的正确MIME

1 个答案: