MyClient.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Microsoft.WindowsAzure.MobileServices;
using Newtonsoft.Json.Linq;

namespace MobileClient.Core
{
    public class MyClient
    {
        public static MobileServiceClient MobileService = new MobileServiceClient(
                "https://mobileapp.azure-mobile.net/",
                "clientkey"
            );

        public Task<JObject> Put(MyData data)
        {
            return MobileService.InvokeApiAsync<MyData, JObject>("sampleapi", data);
        }

        public Task<IEnumerable<MyData>>  Get(string userid)
        {
            return MobileService.InvokeApiAsync<IEnumerable<MyData>>("sampleapi", HttpMethod.Get,
                new Dictionary<string, string> { { "UserId", userid} });
        } 
    }

    public class MyData
    {
        public string UserId { get; set; }
        public string Text { get; set; }
    }
}