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c#jsonrestjson.net
Pavel Brun
Pavel Brun

Reputation: 71

Can you serialize ByteArrayContent in a JSON that translates to C# object?

I have written a C# Web API in VS Studio and have created numerous DTO's that get serialized into JSON entities which any client can consume. One of my API calls is to return a PDF file, so after some online research, I set up one of the DTO's is set up in the following format. I read somewhere you can do this, but not 100% sure:

public class MyCustomResult
{
   public bool Success;
   public DateTime? LastRunDate;
   public string ErrorCode;
   public string Message;
   public ByteArrayContent ReportBody;
}

I do not get any errors when return the object as an IHttpActionResult:

return Ok(result);

I can see on the server that the ByteSize of the report byte[] is approx 700K. However, when I retrieve the object on the client, the JSON entity is approx 400B and no byte content in the ByteContentStream. When I run the query in Postman, I get an empty Header, so it appears that the ByteContentStream can't be serialized by Newtonsoft JSON.

Are there any options I should consider?

Upvotes: 0

Views: 1689

Answers (1)

Andy
Andy

Reputation: 13557

Here is a scenario where you'd use ByteArrayContent:

using(var req = new HttpRequestMessage(HttpMethod.Post, new Uri("https://example.com"))
{
    req.Content = new ByteArrayContent(...);
    using(var resp = await _client.SendAsync(req))
    {
        var data = await resp.Content.ReadAsAsync<object>();
    }
}

What you'd want to do is this:

public class MyCustomResult
{
   public bool Success;
   public DateTime? LastRunDate;
   public string ErrorCode;
   public string Message;
   public byte[] ReportBody; // <-- change this to byte[]
}

var dataToSend = new MyCustomResult(); // fill this in

using(var req = new HttpRequestMessage(HttpMethod.Post, new Uri("https://example.com"))
{
    req.Content = new StringContent(
        JsonConvert.SerializeObject(dataToSend, Encoding.UTF8, "application/json"));
    using(var resp = await _client.SendAsync(req))
    {
        var data = await resp.Content.ReadAsAsync<object>();
    }
}

(note: this code is not tested)

So what will happen is SerializeObject will convert that byte array into a Base64 string then send it.

The consumer would then have to decode that Base64 string. If it's another Newtonsoft.Json client and the model definitions match, then it will automatically decode it for you.

I understand you are doing an API endpoint. The above examples are to show the use of ByteArrayContent and why it exists in .NET. How you are returning data is correct: return Ok(response); as long as you fix your model.

So to sum it up:

ByteArrayContent is an implementation of HttpContent which is supposed to be used as a response body only. It's not to be used in conjunction with a JSON response.

Upvotes: 0

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