Question

我有这个代码示例作为另一个问题（Send a file via HTTP POST with C#）的答案发布。除了一个问题，它工作正常。它用双引号括起HTTP头中的边界：

的multipart / form-data的;边界=＆＃34; 04982073-787d-414B-a0d2-8e8a1137e145＆＃34;

这扼杀了我试图打电话的网络服务。浏览器没有那些双引号。我需要一些方法告诉.NET让他们离开。

private System.IO.Stream Upload(string actionUrl, string paramString, Stream paramFileStream, byte [] paramFileBytes)
{
    HttpContent stringContent = new StringContent(paramString);
    HttpContent fileStreamContent = new StreamContent(paramFileStream);
    HttpContent bytesContent = new ByteArrayContent(paramFileBytes);
    using (var client = new HttpClient())
    using (var formData = new MultipartFormDataContent())
    {
        formData.Add(stringContent, "param1", "param1");
        formData.Add(fileStreamContent, "file1", "file1");
        formData.Add(bytesContent, "file2", "file2");
        var response = client.PostAsync(actionUrl, formData).Result;
        if (!response.IsSuccessStatusCode)
        {
            return null;
        }
        return response.Content.ReadAsStreamAsync().Result;
    }
}

Answer 1

您可以使用以下代码从边界删除引号：

var boundary = formData.Headers.ContentType.Parameters.First(o => o.Name == "boundary"); 
boundary.Value = boundary.Value.Replace("\"", String.Empty);

Answer 2

扩展similar issue in the dotnet runtime repo中的分裂。选择不加引号需要两个步骤

选择您自己的未引用边界
删除不带引号的自动生成的ContentType标头

private System.IO.Stream Upload(string actionUrl, string paramString, Stream paramFileStream, byte [] paramFileBytes)
{
    HttpContent stringContent = new StringContent(paramString);
    HttpContent fileStreamContent = new StreamContent(paramFileStream);
    HttpContent bytesContent = new ByteArrayContent(paramFileBytes);
    //Set your own boundary, otherwise the internal boundary between multiple parts remains with quotes
    string boundaryDelimiter = String.Format("----------{0}", DateTime.Now.Ticks.ToString("x"));
    using (var client = new HttpClient())
    using (var formData = new MultipartFormDataContent(boundaryDelimiter))
    {
        formData.Add(stringContent, "param1", "param1");
        formData.Add(fileStreamContent, "file1", "file1");
        formData.Add(bytesContent, "file2", "file2");
        //remove quotes from ContentType Header
        _multiPartContent.Headers.Remove("Content-Type");
        _multiPartContent.Headers.TryAddWithoutValidation("Content-Type", "multipart/form-data; boundary=" + boundaryDelimiter);

        var response = client.PostAsync(actionUrl, formData).Result;
        if (!response.IsSuccessStatusCode)
        {
            return null;
        }
        return response.Content.ReadAsStreamAsync().Result;
    }
}

Answer 3

这是一个老问题，但我遇到了同样的问题，并以@Luis Perez 在他的回答中指出的相同方式解决了这个问题，但使用它的缺点是 MultipartContent 停止计算内容大小，所以这是我的解决方案：

var multipartContent = new MultipartFormDataContent();
var boundaryParameter = multipartContent.Headers.ContentType
                                        .Parameters.Single(p => p.Name == "boundary");
boundaryParameter.Value = boundaryParameter.Value.Replace("\"", "");

// --- Put the rest of content here

var size = (await multipartContent.ReadAsStreamAsync()).Length;
multipartContent.Headers.ContentLength = size;

希望这对那里的人有所帮助。

HttpContent边界双引号

3 个答案: