SalesforceClient-Query.cs

public string Query (string soqlQuery)
{
    using (var client = new HttpClient())
    {
        string restRequest = InstanceUrl + API_ENDPOINT + "query/?q=" + soqlQuery;
        var request = new HttpRequestMessage(HttpMethod.Get, restRequest);
        request.Headers.Add("Authorization", "Bearer " + AuthToken);
        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        request.Headers.Add("X-PrettyPrint", "1");
        var response = client.SendAsync(request).Result;
        return response.Content.ReadAsStringAsync().Result;
    }
}