C# 如何在OWIN管道上接收web api 2中的多部分/表单数据

我很难让我的WebAPI2方法正确地从AngularUI端的ng文件上传读取我的多部分/表单数据帖子

我是这样打电话的：

Upload.upload({
                url: config.ApiUrl + 'Orders/CreateOrder',
                data: request
            }).then(function (response) {
                console.log('Success ' + response.config.data.file.name + 'uploaded. Response: ' + response.data);
            }, function (error) {
                $scope.errors = "Oops! Something went wrong... " + error.statusText;
            });

这会给我一个有效载荷，发送到web api：

-----------------------------9623122368016
Content-Disposition: form-data; name="somefield"

Some Value
-----------------------------9623122368016
Content-Disposition: form-data; name="errorMessage"

null
-----------------------------9623122368016
Content-Disposition: form-data; name="success"

false
-----------------------------9623122368016
Content-Disposition: form-data; name="file"; filename="imapdf.pdf"
Content-Type: application/pdf

%PDF-1.2
1 0 obj 
<<
/Producer()
/Author()
/Title()
/Subject()
/Keywords()
/CreationDate(D:20040106)
/ModDate(D:20040106)
/Creator()
>> 
endobj
2 0 obj 
<<
/Type/XObject
/Subtype/Image
/Name/wpt1
/Width 41
/Height 15
/BitsPerComponent 8
/ColorSpace/DeviceRGB
/Length 100
/Filter [/FlateDecode] >>
stream
xsqH0s 

---

顾名思义，

ReadAsMultipartAsync

是一个异步函数。因为您没有在等待呼叫，所以您很可能会遇到这样的情况：您试图在填充

内容之前访问

要解决此问题，您可以更新
CreateOrder
操作，如下所示：

public async Task<OrderRequest> CreateOrder(OrderRequest orderRequest)
{
    ...
    await this.Request.Content.ReadAsMultipartAsync(provider);
    ...
}

显然，这不是一个完整的解决方案，但我相信它将解决您的具体问题，并允许您继续探索。
@Kirk Larkin当然，我发布了我的代码，在我的示例中，ReadAsMultipartAsync（provider）在下一行返回空值。
public async Task<OrderRequest> CreateOrder(OrderRequest orderRequest)
{
    ...
    await this.Request.Content.ReadAsMultipartAsync(provider);
    ...
}

public async Task<OrderRequest> CreateOrder(OrderRequest orderRequest)
{
    try
    {
        var asdf = OwinHttpRequestMessageExtensions.GetOwinContext(Request);
        if (!Request.Content.IsMimeMultipartContent("multipart/form-data"))
        {
            var provider = new MultipartMemoryStreamProvider();
            await this.Request.Content.ReadAsMultipartAsync(provider);

            var content = provider.Contents.First();
            var buffer = await content.ReadAsByteArrayAsync();
        }

        var test = orderRequest;
        var a = HttpContext.Current.Request.Files;
    }
    catch (Exception ex)
    {
        throw ex;
    }

    return null;
}