Read Data from SharePoint Online using REST Api for Specific Item

Question

I am successfully connected with SharePoint Online and successfully Updated the List using Rest Api.

Now I am trying to Get item details using ItemID using the following C# Code:

try
{
    Uri uri = new Uri(MasterData.SiteURL);

    using (var client = new SPHttpClient(uri, MasterData.UserID, MasterData.PWD))
    {
        var listTitle = "Overdue POs List";
        var itemPayload = new { __metadata = new { type = "SP.Data.Overdue_x0020_POs_x0020_ListListItem" } };
        var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items({2})", uri, listTitle, ItemID);


        var keyValues = new List<KeyValuePair<string, string>>
                {
                    new KeyValuePair<string, string>("Authorization", "Bearer "+accessToken)
                };

        HttpContent content = new FormUrlEncodedContent(keyValues);

        var httpClient = new HttpClient();
        httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer " + accessToken);

        var response = httpClient.GetAsync(endpointUrl).Result;
        var result = response.Content.ReadAsStringAsync().Result;
        var status = (JsonConvert.DeserializeObject<OverduePOs>(result.ToString())).PO_x0020_Status;
        return status;
    }
}
catch (HttpRequestException ex)
{
    return "";
}

The response is successfully coming in XML Format but I am unable to Desearilize that in JSON:

Response:

Exception:

Newtonsoft.Json.JsonReaderException: 'Unexpected character encountered while parsing value: <. Path '', line 0, position 0.'

can anyone Help to parse results in JSON?

Answer 1

So, by incorporating the provided code snippet into your request body, your concern will be resolved:

httpClient.DefaultRequestHeaders.Add("Accept", "application/json"); // Indicate JSON format

Essentially, this instruction informs the HTTP request to deliver the response in JSON format.

here is your updated code block:

try
{
    Uri uri = new Uri(MasterData.SiteURL);

    using (var client = new SPHttpClient(uri, MasterData.UserID, MasterData.PWD))
    {
        var listTitle = "Overdue POs List";
        var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items({2})", uri, listTitle, ItemID);

        var httpClient = new HttpClient();
        httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer " + accessToken);
        httpClient.DefaultRequestHeaders.Add("Accept", "application/json"); // Specify JSON format

        var response = httpClient.GetAsync(endpointUrl).Result;
        if (response.IsSuccessStatusCode)
        {
            var result = response.Content.ReadAsStringAsync().Result;
            var overduePOs = JsonConvert.DeserializeObject<OverduePOs>(result);
            var status = overduePOs.PO_x0020_Status;
            return status;
        }
        else
        {
            return "";
        }
    }
}
catch (HttpRequestException ex)
{
    return "";
}