vs xamarin android 读取rest

private void Btn_Click(object sender, EventArgs e)

{

    var u = FindViewById<EditText>(Resource.Id.editText1).Text;

    var p = FindViewById<EditText>(Resource.Id.editText2).Text;

    var progressDialog = ProgressDialog.Show(this, "Please wait...", "Checking account info...", true);

    var t=new Thread(new ThreadStart(delegate

    {

        var r = Api.CheckUser(u, p);

        if (r.HasValue)

        {

            RunOnUiThread(() => progressDialog.Hide());

            AppConfig.Config.SetNowUserId(r.Value);

            StartActivity(typeof(MainActivity));

            Finish();

        }

        else

        {

            RunOnUiThread(() => Toast.MakeText(this, "用户名或密码错误", ToastLength.Long).Show());

            RunOnUiThread(() => progressDialog.Hide());

        }

                

    }));

    t.Start();

}

把loading框显示出来，然后开新线程做事，之后关闭loading框。

因为是开新线程，所以如果希望更新界面，需要使用 RunOnUiThread方法

还有另外的方式

 

private readonly TaskScheduler uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();

private void Btn_Click(object sender, EventArgs e)

{

    var u = FindViewById<EditText>(Resource.Id.editText1).Text;

    var p = FindViewById<EditText>(Resource.Id.editText2).Text;

    var progressDialog = ProgressDialog.Show(this, "Please wait...", "Checking account info...", true);

    Task.Factory.StartNew(() =>

    {

        return Api.CheckUser(u, p);

    }).ContinueWith(r =>

    {

        progressDialog.Hide();

        if (r.Result.HasValue)

        {

            AppConfig.Config.SetNowUserId(r.Result.Value);

            StartActivity(typeof(MainActivity));

            Finish();

        }

        else

        {

            Toast.MakeText(this, "用户名或密码错误", ToastLength.Long).Show();

        }

                

    }, uiScheduler);

}

使用Task的ContinueWith，可以指定在ui上执行

 

访问网络需要给permission，在项目属性里，Android Manifest 下面列出了所有的permission，打钩internet