using Android.App;
using Android.Widget;
using Android.OS;
using System.Threading;

namespace AsyncTaskDemo
{
    [Activity(Label = "AsyncTaskDemo", MainLauncher = true)]
    public class MainActivity : Activity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            Button btn = FindViewById<Button>(Resource.Id.button1);

            btn.Click += (s, e) =>
            {
                 new InitTask(this).Execute();      //调用异步任务
            };
        }

        //开启一个线程，沉睡10秒，模拟上传数据
        void TestThead()
        {
            Thread.Sleep(10000);
        } 


        private class InitTask : AsyncTask<Java.Lang.Void, Java.Lang.Void, string[]>
        {

            MainActivity main;
            ProgressDialog proDialg = null;

            public InitTask(MainActivity _main)
            {
                main = _main;
            }

            protected override string[] RunInBackground(params Java.Lang.Void[] @params)
            {
                //throw new NotImplementedException ();
                return null;
            }

            //后台要执行的任务
            protected override Java.Lang.Object DoInBackground(params Java.Lang.Object[] @params)
            {
                main.TestThead();
                return "OK";
            }

            //执行后返回
            protected override void OnPostExecute(Java.Lang.Object result)
            {
                proDialg.Cancel();
                if (result.ToString() != "OK")
                    Toast.MakeText(main, "获取数据失败!", ToastLength.Short); 
            }

            //开始执行任务
            protected override void OnPreExecute()
            {
                proDialg = new ProgressDialog(main);
                proDialg.SetProgressStyle(ProgressDialogStyle.Spinner);
                //设置界面不可操作 返回键有效
                //proDialg.SetCanceledOnTouchOutside(false);
                proDialg.SetMessage("正在上传数据...");
                //设置界面不可操作 返回键无效     
                proDialg.SetCancelable(false);
                proDialg.Show();
            }
        }
    }
}