如何从WinRT调用WebAPI

Question

I try to call a WebAPI from WinRT. In WinRT I wrote serializable classes, which I want to be sent to the WebAPI:

[DataContractAttribute]
public class RecognizeItem
{
    [DataMember()]
    public string Id { get; set; }

    [DataMember()]
    public Windows.UI.Xaml.Media.Imaging.BitmapImage Image { get; set; }
}

Next step send data to server:

            RecognizeItem system = new RecognizeItem()
            {
                Id = login,
                Image = LoadImage
            };
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            string json = JsonConvert.SerializeObject(system);
            HttpContent content = new StringContent(json); 
            HttpResponseMessage response = await client.PostAsync("api/RecognizeItem/", content);

In the implementation of the webAPI I have implemented a serializable class as follows:

[Serializable]
public class RecognizeItem
{
    public string Id { get; set; }

    public Bitmap Image { get; set; }

}

And my ApiController:

public string Post([FromBody] RecognizeItem image)...

But in response I see the following status:

StatusCode: 415, ReasonPhrase: 'Unsupported Media Type'

How can I fix this error?

Answer 1

I believe Content-Type is a header of the content, not of the request.

Try setting your content by passing the content-type to the StringContent constructor:

Replace

HttpContent content = new StringContent(json);

by

HttpContent content = new StringContent(json,
                                Encoding.UTF8, 
                                "application/json");