Can't convert string to system.Net.HttpContent

Question

Here I'm trying to get data from the services:

public async Task<IHttpActionResult> ValidateSesion()
{
    var values = new Dictionary<string, string>{
        { "productId", "1" },
        { "productKey", "Abc6666" },
        { "userName", "OPPO" },
    };
    var json = JsonConvert.SerializeObject(values, Formatting.Indented);
    // var content = new FormUrlEncodedContent(json);
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
    var response = await client.PostAsync("http://172.116.12.172:8014/iadmin/validate", json);
    var responseString = await response.Content.ReadAsStringAsync();
    return Ok(responseString);
}

If I make any PostMan call, like below, the data i get looks like this:

{
    "productId": "1",
    "productKey": "Abc6666" 
}

Can you provide the full stacktrace of your error? This can help us to identify the precise place where error occurs... — Pietro Martinelli, Feb 05 '19 at 07:56
None of the PostAsync methods accepts a string. Trying to pass a string raises a compilation error. — Panagiotis Kanavos, Feb 05 '19 at 08:02

score 19 · Accepted Answer · answered Feb 05 '19 at 07:59

You can't post a raw string, you have to wrap it in a StringContent: new StringContent(json);

This should do the trick:

public async Task<IHttpActionResult> ValidateSesion()
{
    var values = new Dictionary<string, string>{
      { "productId", "1" },
      { "productKey", "Abc6666" },
      { "userName", "OPPO" },
    };

    var json = JsonConvert.SerializeObject(values, Formatting.Indented);

    var stringContent = new StringContent(json);

    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    var response = await client.PostAsync("http://172.116.12.172:8014/iadmin/validate", stringContent);

    var responseString = await response.Content.ReadAsStringAsync();

    return Ok(responseString);
}

To use System.Text.Json it could be `var json = JsonSerializer.Serialize( values );` — StackOverflowUser, Aug 28 '23 at 02:07

score -1 · Answer 2 · answered Feb 05 '19 at 07:55

-1

Change your return statement like

return Content(responseString);

answered Feb 05 '19 at 07:55

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Can't convert string to system.Net.HttpContent

2 Answers2