C# - Body content in POST request

Question

I need to make some api calls in C#. I'm using Web API Client from Microsoft to do that. I success to make some POST requests, but I don't know how to add the field "Body" into my requests. Any idea ? Here's my code:

    static HttpClient client = new HttpClient();
    public override void AwakeFromNib()
    {
        base.AwakeFromNib();
        notif_button.Activated += (sender, e) => {
        };
        tips_button.Activated += (sender, e) =>
        {
            Tip t1 = new Tip(title_tips.StringValue, pic_tips.StringValue, content_tips.StringValue, "TEST");
            client.BaseAddress = new Uri("my_url");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            CreateProductAsync(t1).Wait();
        };
    }

    static async Task<Uri> CreateProductAsync(Tip tips)
    {
        HttpResponseMessage response = await client.PostAsJsonAsync("api/add_tips", tips);
        response.EnsureSuccessStatusCode();
        return response.Headers.Location;
    }

Answer 1

Step 1. Choose a type that derives from HttpContent. If you want to write a lot of content with runtime code, you could use a StreamContent and open some sort of StreamWriter on it. For something short, use StringContent. You can also derive your own class for custom content.

Step 2. Pass the content in a call to HttpClient.PostAsync.

Here's an example that uses StringContent to pass some JSON:

string json = JsonConvert.SerializeObject(someObject);
var httpContent = new StringContent(json, Encoding.UTF8, "application/json");
var httpResponse = await httpClient.PostAsync("http://www.foo.bar", httpContent);

See also How do I set up HttpContent?.