using System;using System.Collections.Generic;using System.Linq;using System.Reflection.Emit;using System.Text;using Xamarin.Forms;namespace PageApp{    public class MainMasterPage : MasterDetailPage    {        public MainMasterPage()        {            Label header = new Label            {                Text = "MasterDetailPage",                Font = Font.BoldSystemFontOfSize(30),                HorizontalOptions = LayoutOptions.Center            };            int[] a = new int[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 11, 11, 22, 112 };            ListView listView = new ListView            {                ItemsSource = a            };            listView.ItemSelected += ListView_ItemSelected;            Master = new ContentPage            {                Title = header.Text,                Content = new StackLayout                {                    Children =                    {                        header,                        listView                    }                }            };            Detail = new ContentPage() { Content = new Label() { Text = "测试" } };        }        private void ListView_ItemSelected(object sender, SelectedItemChangedEventArgs e)        {            this.Detail = new ContentPage() { Content = new Label() { Text =  e.SelectedItem.ToString() } };            //if (Device.OS == TargetPlatform.Android)            //{            //    this.Navigation.PopAsync();                            //}        }    }}