Added retry action for timed out connections, fixed error message popup on export thread

GUT.Schedule/GUT.Schedule/Activities/ExportActivity.cs

@@ -1,10 +1,10 @@
 using Android.App;
-using Android.Content;
 using Android.OS;
 using Android.Widget;
 using GUT.Schedule.Models;
 using System;
 using System.Collections.Generic;
+using System.Net.Http;
 using System.Threading.Tasks;
 
 namespace GUT.Schedule
@@ -17,13 +17,18 @@ namespace GUT.Schedule
     {
         TextView status;
 
-        protected override async void OnCreate(Bundle savedInstanceState)
+        protected override void OnCreate(Bundle savedInstanceState)
         {
             base.OnCreate(savedInstanceState);
             SetContentView(Resource.Layout.export_progress);
 
             status = FindViewById<TextView>(Resource.Id.status);
 
+            Export();
+        }
+
+        private async void Export()
+        {
             try
             {
                 status.Text = "Загрузка расписания";
@@ -38,15 +43,28 @@ namespace GUT.Schedule
                 status.Text = "Готово";
                 await Task.Delay(1000);
             }
+            catch (HttpRequestException e)
+            {
+                Android.Support.V7.App.AlertDialog.Builder builder = new Android.Support.V7.App.AlertDialog.Builder(this);
+                builder.SetMessage("Невозможно загрузить расписание. Проверьте интернет-соединение или попробуйте позже")
+                    .SetTitle(e.Message)
+                    .SetPositiveButton("ОК", (s, e) => base.OnBackPressed())
+                    .SetNegativeButton("Повторить", (s, e) => Export());
+
+                Android.Support.V7.App.AlertDialog dialog = builder.Create();
+                dialog.Show();
+                return;
+            }
             catch (Exception e)
             {
                 Android.Support.V7.App.AlertDialog.Builder builder = new Android.Support.V7.App.AlertDialog.Builder(this);
                 builder.SetMessage(e.Message)
                     .SetTitle(e.GetType().ToString())
-                    .SetPositiveButton("ОК", (EventHandler<DialogClickEventArgs>)null);
+                    .SetPositiveButton("ОК", (s, e) => base.OnBackPressed());
 
                 Android.Support.V7.App.AlertDialog dialog = builder.Create();
                 dialog.Show();
+                return;
             }
             base.OnBackPressed();   // Navigates back to main activity (always because I don't allow backward navigation)
         }

GUT.Schedule/GUT.Schedule/Activities/StartActivity.cs

@@ -61,6 +61,11 @@ namespace GUT.Schedule
                 using HttpClient client = new HttpClient();
                 Data.FirstWeekDay = int.Parse(await client.GetStringAsync("https://xfox111.net/schedule_offset.txt"));
             }
+            catch(HttpRequestException e)
+            {
+                ShowDialog(e.Message, "Невозможно загрузить расписание. Проверьте интернет-соединение или попробуйте позже", Proceed, FinishAndRemoveTask, "Повторить", "Выйти");
+                return;
+            } 
             catch (Exception e)
             {
                 ShowDialog(e.GetType().ToString(), e.Message, FinishAndRemoveTask);
@@ -85,14 +90,16 @@ namespace GUT.Schedule
                 Manifest.Permission.ReadCalendar, 
                 Manifest.Permission.WriteCalendar,
                 Manifest.Permission.Internet
-            }, 76);     // IDK why I need requestCode value to be set (instead of 76 there can be any other number. Anyway it doesn't affect anything)
+            }, 0);
 
-        private void ShowDialog(string title, string content, Action action = null)
+        private void ShowDialog(string title, string content, Action posAction = null, Action negAction = null, string posActionLabel = null, string negActionLabel = null)
         {
             Android.Support.V7.App.AlertDialog.Builder builder = new Android.Support.V7.App.AlertDialog.Builder(this);
             builder.SetMessage(content)
-                .SetTitle(title)
-                .SetPositiveButton("ОК", (s, e) => action?.Invoke());
+                .SetTitle(title).SetPositiveButton(posActionLabel ?? "OK", (s, e) => posAction?.Invoke());
+
+            if (negAction != null)
+                builder.SetNegativeButton(negActionLabel ?? "Close", (s, e) => negAction.Invoke());
 
             Android.Support.V7.App.AlertDialog dialog = builder.Create();
             dialog.Show();

GUT.Schedule/GUT.Schedule/Properties/AndroidManifest.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="104" android:versionName="1.0.4" package="com.xfox111.gut.schedule" android:installLocation="auto">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="105" android:versionName="1.0.5" package="com.xfox111.gut.schedule" android:installLocation="auto">
 	<uses-sdk android:minSdkVersion="16" android:targetSdkVersion="28" />
 	<application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="ГУТ.Расписание" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme.NoActionBar"></application>
 	<uses-permission android:name="android.permission.READ_CALENDAR" />