Seems to work

Päevaküsimus/App.xaml

@@ -2,7 +2,8 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:local="clr-namespace:Päevaküsimus"
-             StartupUri="MainWindow.xaml">
+             StartupUri="MainWindow.xaml"
+             Exit="App_OnExit">
     <Application.Resources>
          
     </Application.Resources>

Päevaküsimus/App.xaml.cs

@@ -13,5 +13,15 @@ namespace Päevaküsimus
     /// </summary>
     public partial class App : Application
     {
+        public static MainWindowVM mwvm;
+        private void App_OnExit(object sender, ExitEventArgs e)
+        {
+            if (App.mwvm != null)
+            {
+                SerializationService.Serialize(App.mwvm.questions);
+            }
+        }
+
+
     }
 }

Päevaküsimus/MainWindow.xaml

@@ -19,15 +19,16 @@
                     <ColumnDefinition />
                 </Grid.ColumnDefinitions>
                 <Label Grid.Column="0" Grid.Row="0" Content="Päevaküsimus on:"/>
-                <Label Grid.Column="1" Grid.Row="0" Content="Placeholder"/>
+                <Label Grid.Column="1" Grid.Row="0" Content="{Binding dayQuestion.question}"/>
                 <Label Grid.Column="0" Grid.Row="1" Content="Vali õige vastuse variant"/>
-                <ListBox Grid.Row="2" Grid.Column="0"  Grid.ColumnSpan="2">
+                <ListBox Grid.Row="2" Grid.Column="0"  Grid.ColumnSpan="2" ItemsSource="{Binding dayQuestion.answers}" x:Name="gameAnswerSelectionListBox" SelectionChanged="GameAnswerSelectionListBox_OnSelectionChanged">
                     <ListBox.ItemTemplate>
                         <DataTemplate>
-                            <Label Content="Bla" />
+                            <Label Content="{Binding answer}" />
                         </DataTemplate>
                     </ListBox.ItemTemplate>
                 </ListBox>
+                <Button x:Name="displayNewQuestion" Content="Kuva uus küsimus" Grid.Column="1" HorizontalAlignment="Right" Margin="0,0,0,0" Grid.Row="1" Padding="7,0" Click="DisplayNewQuestion_OnClick"/>
             </Grid>
         </TabItem>
         <TabItem Header="Admin">
@@ -42,7 +43,7 @@
                 </Grid.ColumnDefinitions>
                 <Label Grid.Row="0" Grid.Column="0" Content="Küsimused"></Label>
                 <Label Grid.Row="0" Grid.Column="1" Content="Vaata/Muuda"></Label>
-                <ListBox x:Name="allQuestionsListBox" Grid.Column="0" Grid.Row="1" ItemsSource="{Binding questions}" SelectionChanged="AllQuestionsListBox_OnSelectionChanged">
+                <ListBox x:Name="allQuestionsListBox" Grid.Column="0" Grid.Row="1" ItemsSource="{Binding questions}" SelectionChanged="AllQuestionsListBox_OnSelectionChanged" Width="150">
                     <ListBox.ItemTemplate>
                         <DataTemplate>
                             <Label Content="{Binding question}" />
@@ -57,14 +58,25 @@
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="Auto"></ColumnDefinition>
                         <ColumnDefinition></ColumnDefinition>
+                        <ColumnDefinition Width="Auto"></ColumnDefinition>
                     </Grid.ColumnDefinitions>
                     <Label Grid.Row="0" Grid.Column="0" Content="Küsimus:"></Label>
-                    <TextBox Grid.Row="0" Grid.Column="1" Text="Uus Küsimus?"></TextBox>
+                    <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding selectedQuestion.question}" KeyUp="QuestionQuestionTextBox_OnKeyUp"  x:Name="questionQuestionTextBox"/>
-
+                    <DataGrid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="3" ItemsSource="{Binding selectedQuestion.answers}" AutoGenerateColumns="False" CanUserAddRows="False" CanUserDeleteRows="False">
-                    <DataGrid Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" x:Name="dataGrid" ItemsSource="{Binding selectedQuestion.answers}">
+                        <DataGrid.Columns>
-                        
+                            <DataGridTextColumn Header="Vastus" IsReadOnly="False" Binding="{Binding answer}" Width="*">
+                            </DataGridTextColumn>
+                            <DataGridCheckBoxColumn Header="Õige?" IsReadOnly="False" Binding="{Binding correct}">
+                            </DataGridCheckBoxColumn>
+                            <DataGridTemplateColumn Header="Vastanuid" IsReadOnly="True">
+                                <DataGridTemplateColumn.CellTemplate>
+                                    <DataTemplate>
+                                        <Label Content="{Binding selectionCount}" Margin="0" Padding="0" HorizontalContentAlignment="Center"/>
+                                    </DataTemplate>
+                                </DataGridTemplateColumn.CellTemplate>
+                            </DataGridTemplateColumn>
+                        </DataGrid.Columns>
                     </DataGrid>
-
                 </Grid>
             </Grid>
         </TabItem>

Päevaküsimus/MainWindow.xaml.cs

@@ -31,14 +31,34 @@ namespace Päevaküsimus
 
         private void AllQuestionsListBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
         {
-            if (this.allQuestionsListBox.SelectedIndex > -1)
+            if (this.allQuestionsListBox.SelectedIndex > 0)
             {
                 _vm.selectedQuestion = allQuestionsListBox.SelectedItem as Question;
             }
-            else
+            else if (this.allQuestionsListBox.SelectedIndex == 0)
             {
-                _vm.selectedQuestion = new Question("Uus küsimus");
+                this.allQuestionsListBox.SelectedItem = _vm.CreateNewQuestion();
-            }
+            }
+            this.questionQuestionTextBox.SelectAll();
+            this.questionQuestionTextBox.Focus();
+        }
+        
+        private void QuestionQuestionTextBox_OnKeyUp(object sender, KeyEventArgs e)
+        {
+            _vm.selectedQuestion.question = questionQuestionTextBox.Text;
+        }
+
+        private void DisplayNewQuestion_OnClick(object sender, RoutedEventArgs e)
+        {
+            _vm.dayQuestion = _vm.GetQuestionOfTheDay();
+        }
+
+        private void GameAnswerSelectionListBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            var answer = gameAnswerSelectionListBox.SelectedItem as Answer;
+            var winText = answer.correct ? "You WON!" : "Vale vastus :(";
+            MessageBox.Show($"Peale sinu on selle vastuse valinud veel {answer.selectionCount} inimest.", winText);
+            answer.selectionCount++;
         }
     }
 }

Päevaküsimus/MainWindowVM.cs

@@ -8,7 +8,7 @@ using Päevaküsimus.Models;
 
 namespace Päevaküsimus
 {
-    class MainWindowVM:NotificationBase
+    public class MainWindowVM : NotificationBase
     {
         public ObservableCollection<Question> questions { get; set; }
         private Question _seleceQuestion;
@@ -17,39 +17,59 @@ namespace Päevaküsimus
             set
             {
                 _seleceQuestion = value;
-                selectedQuestionAnswers = value.answers;
                 NotifyPropertyChanged();
             }
         }
 
-        private ObservableCollection<Answer> _selectedQuestionAnswers;
+        private Question _dayQuestion;
-        public ObservableCollection<Answer> selectedQuestionAnswers {
+        public Question dayQuestion
-            get { return _selectedQuestionAnswers; }
+        {
+            get { return _dayQuestion; }
             set
             {
-                _selectedQuestionAnswers = value;
+                _dayQuestion = value;
                 NotifyPropertyChanged();
             }
         }
+
         private Random _rnd;
 
         public MainWindowVM()
         {
             this._rnd = new Random();
-            this.questions = new ObservableCollection<Question>();
+            this.questions = SerializationService.DeSerialize();
-            var question = new Question("Mis värvi on armastus?");
+            if (this.questions == null)
-            question.AddAnswer(new Answer("Punane", true));
-            foreach (var color in new [] {"Roheline", "Sinine", "Roosa", "Lilla"})
             {
-                question.AddAnswer(new Answer(color));
+                this.questions = new ObservableCollection<Question>();
-            }
+                var question = new Question("Lisa uus küsimus");
                 this.questions.Add(question);
-            this.questions.Add(new Question("Test"));
+            }
+            App.mwvm = this;
+        }
+
+        public Question CreateNewQuestion()
+        {
+            var question = new Question("Ja minu uueks küsimuseks on?");
+            question.AddAnswer(new Answer("Õige vastus 1", true));
+            foreach (var answer in new[] { "Vale vastus 1", "Vale vastus 2", "Vale vastus 3", "Vale vastus 4" })
+            {
+                question.AddAnswer(new Answer(answer));
+            }
+            this.questions.Insert(1, question);
+            this.selectedQuestion = question;
+            return question;
         }
 
         public Question GetQuestionOfTheDay()
         {
-            return this.questions.ElementAt(this._rnd.Next(0, this.questions.Count));
+            try
+            {
+                return this.questions.ElementAt(this._rnd.Next(1, this.questions.Count));
+            }
+            catch (ArgumentOutOfRangeException e)
+            {
+                return new Question("Palun lisa süsteemi mõni küsimus!");
+            }
         }
 
 

Päevaküsimus/Models/Answer.cs

@@ -3,11 +3,30 @@ using System.Collections;
 
 namespace Päevaküsimus.Models
 {
-    public class Answer
+    [Serializable()]
+    public class Answer : NotificationBase, ICloneable
     {
-        public string answer { get; set; }
+        private string _answer;
+        public string answer {
+            get { return _answer; }
+            set
+            {
+                _answer = value;
+                NotifyPropertyChanged();
+            }
+        }
         public bool correct { get; set; }
-        public int selectionCount { get; set; }
+        private int _selectionCount;
+
+        public int selectionCount
+        {
+            get { return _selectionCount; }
+            set
+            {
+                _selectionCount = value;
+                NotifyPropertyChanged();
+            }
+        }
 
         public Answer(string answer)
         {
@@ -20,5 +39,12 @@ namespace Päevaküsimus.Models
             this.answer = answer;
             this.correct = correct;
         }
+
+        public object Clone()
+        {
+            var c = new Answer(answer.Clone() as string, correct);
+            c.selectionCount = selectionCount;
+            return c;
+        }
     }
 }

Päevaküsimus/Models/Question.cs

@@ -4,10 +4,20 @@ using System.Collections.ObjectModel;
 
 namespace Päevaküsimus.Models
 {
-    public class Question
+    [Serializable()]
+    public class Question : NotificationBase, ICloneable
     {
-        public string question { get; set; }
+        private string _question;
+        public string question {
+            get { return _question; }
+            set
+            {
+                _question = value;
+                NotifyPropertyChanged();
+            }
+        }
         private ObservableCollection<Answer> _answers;
+        public ObservableCollection<Answer> answers { get { return _answers; } }
 
         public Question(string question)
         {
@@ -15,11 +25,19 @@ namespace Päevaküsimus.Models
             this._answers = new ObservableCollection<Answer>();
         }
 
-        public ObservableCollection<Answer> answers { get { return _answers; } }
-
         public void AddAnswer(Answer answer)
         {
             _answers.Add(answer);
         }
+
+        public object Clone()
+        {
+            var q = new Question(_question.Clone() as string);
+            foreach (var answer in _answers)
+            {
+                q.AddAnswer(answer.Clone() as Answer);
+            }
+            return q;
+        }
     }
 }

Päevaküsimus/NotificationBase.cs

@@ -4,6 +4,7 @@ using System.Runtime.CompilerServices;
 
 namespace Päevaküsimus
 {
+    [Serializable()]
     public class NotificationBase : INotifyPropertyChanged
 
     {

Päevaküsimus/Päevaküsimus.csproj

@@ -57,6 +57,7 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </ApplicationDefinition>
+    <Compile Include="SerializationService.cs" />
     <Page Include="MainWindow.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>

Päevaküsimus/SerializationService.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Runtime.Serialization.Formatters.Binary;
+using Päevaküsimus.Models;
+
+namespace Päevaküsimus
+{
+    public class SerializationService
+    {
+        static private string _fileName = "data.bin";
+
+        public static void Serialize(object o)
+        {
+            using (Stream stream = new FileStream(_fileName, FileMode.Create, FileAccess.Write, FileShare.Write))
+            {
+                BinaryFormatter binaryFormatter = new BinaryFormatter();
+                binaryFormatter.Serialize(stream, o);
+            }
+        }
+
+        public static ObservableCollection<Question> DeSerialize ()
+        {
+            try
+            { 
+                using (Stream stream = new FileStream(_fileName, FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read))
+                {
+                    BinaryFormatter binaryFormatter = new BinaryFormatter();
+                    ObservableCollection<Question> questions = binaryFormatter.Deserialize(stream) as ObservableCollection<Question>;
+                    return questions;
+                }
+            }
+            catch (Exception ex)
+            {
+                System.Diagnostics.Trace.WriteLine("Error: " + ex.Message);
+                return null;
+            }
+        }
+    }
+}