update

Former-commit-id: f266ec0b3d7fe031c5ae3e148d0e04e916bbc615

labs/XamarinApp/XamarinApp/MainPage.xaml.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.IO;
 using System.Threading.Tasks;
 using Xamarin.Forms;
 
@@ -8,11 +9,18 @@ namespace XamarinApp
     [DesignTimeVisible(false)]
     public partial class MainPage : ContentPage
     {
+        private string _configFile;
         private string _baseUrl = "http://192.168.1.8";
 
         public MainPage()
         {
             InitializeComponent();
+            this._configFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "config.txt");
+            if (!File.Exists(this._configFile))
+            {
+                File.WriteAllText(this._configFile, this._baseUrl);
+            }
+            this.webView.Source = this._baseUrl;
             this.Appearing += MainPage_Appearing;
         }
 
@@ -35,7 +43,8 @@ namespace XamarinApp
 
         private async Task SetBaseUrl()
         {
-            this._baseUrl = await DisplayPromptAsync("服务器", "配置服务器地址", "确定", "取消", this._baseUrl ?? "http://example.com", keyboard: Keyboard.Url, initialValue: this._baseUrl);
+            this._baseUrl = await DisplayPromptAsync("服务器", "配置服务器地址", "确定", "取消", this._baseUrl, keyboard: Keyboard.Url, initialValue: this._baseUrl);
+            File.WriteAllText(this._configFile, this._baseUrl);
             this.webView.Source = this._baseUrl;
         }
     }