一些踩过的坑

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Runtime.Serialization.Json;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Platform.Facilitys
{
    public static class HttpHelper
    {
        

        static readonly HttpClient _client;
        static HttpHelper()
        {
            _client = new HttpClient();
        }
        
        public static TOut PostSync<TIn, TOut>(ApiHost host, TIn postData)
           where TIn : class
           where TOut : class
        {
            var uri = new Uri(host.Domain);
            var url = new Uri(uri, host.ApiName);
            var response = _client.PostAsync(url, new StringContent(JsonConvert.SerializeObject(postData),Encoding.UTF8,host.DataMimeType)).Result;
            response.EnsureSuccessStatusCode();
            return response.Content.DesObj<TOut>();

        }

        public static Task<TOut> PostAsync<TIn, TOut>(ApiHost host, TIn postData)
           where TIn : class
           where TOut : class
        {
            var uri = new Uri(host.Domain);
            var url = new Uri(uri, host.ApiName);
            return _client.PostAsync(url, new StringContent(JsonConvert.SerializeObject(postData), Encoding.UTF8, host.DataMimeType)).GetResult<TOut>();
        }

        public static Task<TOut> GetAsync<TOut>(ApiHost host)
           where TOut : class
        {
            var uri = new Uri(host.Domain);
            var url = new Uri(uri, host.ApiName);
            return _client.GetAsync(url).GetResult<TOut>();
        }

        static Task<TOut> GetResult<TOut>(this Task<HttpResponseMessage> tsk)
           where TOut : class
        {
            return tsk.ContinueWith(
                res =>
                {
                    return res
                            .Result
                            .EnsureSuccessStatusCode()
                            .Content
                            .DesObj<TOut>();
                }, TaskContinuationOptions.OnlyOnRanToCompletion);
        }

        static TOut DesObj<TOut>(this HttpContent content)
           where TOut : class
        {
            var strJson = content.ReadAsStringAsync().Result;
            if (!string.IsNullOrWhiteSpace(strJson))
            {
                if (strJson.IndexOf("k__BackingField") > 0)
                {
                    DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(TOut));
                    using (var mStream = new MemoryStream(Encoding.Default.GetBytes(strJson)))
                    {
                        return ser.ReadObject(mStream) as TOut;
                    }

                }
                else
                {
                    return JsonConvert.DeserializeObject<TOut>(strJson);
                }
            }
            return default(TOut);
        }
    }


    /// <summary>
    /// WebApi配置
    /// </summary>
    public class ApiHost
    {
        #region
        public ApiHost()
        {
            DataMimeType = "application/json";
        }
        public ApiHost(string domain, string apiName, string inputQueryString, string dataMimeType)
        {
            Domain = domain;
            ApiName = apiName;
            InputQueryString = inputQueryString;
            DataMimeType = dataMimeType;
        }
        #endregion
        #region
        /// <summary>
        /// 主域名(比如http://api.rongzi.com or http://127.0.0.1)
        /// </summary>
        public string Domain { get; set; }

        /// <summary>
        /// Api名称(api/v1/studentinfotest)
        /// </summary>
        public string ApiName { get; set; }

        /// <summary>
        /// 传入参数名称
        /// </summary>
        public string InputQueryString { get; set; }

        /// <summary>
        /// 返回数据类型
        /// </summary>
        public string DataMimeType { get; set; }

        /// <summary>
        /// 重写ToString()
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return string.Format("{0}|{1}|{2}|{3}",
                this.ApiName,
                this.Domain,
                this.DataMimeType,
                this.InputQueryString);
        }
        #endregion
    }

}

int b = int.MaxValue;
b++;//这里不会抛出异常，b变为-2147483648

unchecked
{
   int a = int.MaxValue;
   a++;//这里也不会抛出异常，a变成-2147483648
}
checked
{
   int a = int.MaxValue;
   a++;//这里抛出异常，超出最大值
}