Xamarin.Android 使用Timer 并更改UI

http://blog.csdn.net/ozhangsan12345/article/details/72653070

第一步：创建timer对象

//创建timer对象
      Timer _dispatcherTimer;
      //计数
      int sec = 60;

第二步： 实例化timer并给委托事件

TimerCallback timerDelegate = new TimerCallback(Tick); //tick为执行防范
_dispatcherTimer = new Timer(timerDelegate, null, 0, 1000);

//执行方法

public void Tick(object state)
      {
          this.RunOnUiThread(() =>
          {
              if (sec > 0)
              {
                  smsbt.Text = sec.ToString() + "秒可重发";
                  sec--;
              }
              else
              {
                  _dispatcherTimer.Dispose();
                  sec = 60;
                  smsbt.Text = "获取验证码";

              }
          });

      }

//使用

{
                       TimerCallback timerDelegate = new TimerCallback(Tick);
                       _dispatcherTimer = new Timer(timerDelegate, null, 0, 1000);
                       ProgressDialog progressDialog = ProgressDialog.Show(this, "", "请稍后...");
                       new Thread(new ThreadStart(() =>
                       {

                           string url = this.GetString(Resource.String.url) + "/AppServices/userServices.aspx?action=regSms";

                           using (var http = new HttpClient())
                           {
                               var content = new FormUrlEncodedContent(new Dictionary<string, string>() {
                       { "phone",userphone.Text }
                           });
                               var response = http.PostAsync(url, content);
                               string me = response.Result.Content.ReadAsStringAsync().Result;
                               progressDialog.Dismiss();
                               this.RunOnUiThread(() =>
                               {
                               HandleResult(me);
                               });
                           }
                       })).Start();
                   }