protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
txtInput = FindViewById<EditText>(Resource.Id.txt_input);
btnPost = FindViewById<Button>(Resource.Id.btn_post);
btnGet = FindViewById<Button>(Resource.Id.btn_get);
btnGetHWR = FindViewById<Button>(Resource.Id.btn_getHWR);
btnPostHWR = FindViewById<Button>(Resource.Id.btn_postHWR);
tv = FindViewById<TextView>(Resource.Id.tv_result);
//based on httpclient
btnPost.Click += PostRequest;
btnGet.Click += GetRequest;
//based on httpwebrequest
btnPostHWR.Click += PostRequestByHWR;
btnGetHWR.Click += GetRequestByHWR;
}