How do i read a multipart/related content

[bhuvikris]

Using refit, how can i read a Multipart response. It is a Get call.
Accept: multipart/related
How do deal with partial content response ?

[glennawatson]

Refit does not parse multipart/related responses for you. There is no built-in multipart-response reader; built-in raw types on the response side are Stream, string, HttpResponseMessage and HttpContent.

Approach:

• Declare the method to return the raw response and parse the parts yourself:

[Get("/resource")]
[Headers("Accept: multipart/related")]
Task<HttpResponseMessage> GetParts();

Then read it with MultipartMemoryStreamProvider from System.Net.Http:

using var resp = await api.GetParts();
var multipart = await resp.Content.ReadAsMultipartAsync();
foreach (var part in multipart.Contents)
{
    var bytes = await part.ReadAsByteArrayAsync();
    // inspect part.Headers for content-type / content-id
}

Notes:

• ReadAsMultipartAsync lives in the System.Net.Http.Formatting package (Microsoft.AspNet.WebApi.Client). If you prefer no extra dependency, read the raw Stream and split on the boundary from the Content-Type header yourself.
• For partial content (HTTP 206 / Range), set the Range header (e.g. via [Headers] or a HttpRequestMessage) and read resp.StatusCode / Content-Range from the returned HttpResponseMessage.

In short: return HttpResponseMessage from Refit and do the multipart/range handling with the standard HttpClient types.