4. Build SingleSuggestion Window

Add UI Components

Let’s modify the UI of the SingleSuggestion window.

1. Go to SingleSuggestion.xaml file.
2. Modify backBtn and add a button (getSuggestionBtn),  text blocks (suggestionTxt), radio buttons (breakfastRbtn). Check the provided code below to understand better. It is for the most outer grid.

   <Grid>
       <Button x:Name="backBtn" Content="Back to Main"  HorizontalAlignment="Left" Margin="26,26,0,0" VerticalAlignment="Top" Width="140" Height="45" Click="backBtn_Click"/>
       <RadioButton GroupName="breakfast" Content="Breakfast" x:Name="breakfastRbtn" IsChecked="True" HorizontalAlignment="Left" Margin="248,124,0,0" VerticalAlignment="Top" RenderTransformOrigin="1.075,0.533"/>
       <RadioButton GroupName="breakfast" Content="Lunch or Dinner" HorizontalAlignment="Left" Margin="438,124,0,0" VerticalAlignment="Top"/>
       <Button x:Name="getSuggestionBtn" Content="Get Suggestion" HorizontalAlignment="Left" Margin="248,165,0,0" VerticalAlignment="Top" Width="294" Height="47"/>
       <TextBlock x:Name="suggestionTxt" Text="" TextAlignment="Center" FontWeight="Bold" FontSize="40" HorizontalAlignment="Left" Margin="26,261,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Height="84" Width="745"/>
   </Grid>
   

Add Database Context

This part is the same as the last chapter.

1. Go to SingleSuggestion.xaml.cs file.
2. Under declaration for ParentWindow, declare a private MealSuggestionContainer field named _context.

   private MealSuggestionContainer _context;
   

3. Inside of the constructor, create a new MealSuggestionContainer for _context.

   //create data context
   _context = new MealSuggestionContainer();
   

Add Controller

1. Go to SingleSuggestion.xaml.cs file.
2. Add variables needed for getSuggestionBtn_Click function under declaration for _context.

   int lastDish = -1;
   bool lastBreakfast = true;
   

3. Add getSuggestionBtn_Click function. Check the code below.

   private void getSuggestionBtn_Click(object sender, RoutedEventArgs e)
   {
       Dish[] candidates;
   
       try
       {
           //breakfast
           if ((bool)breakfastRbtn.IsChecked)
           {
               //get dishes for breakfast
               var dishes = from d in _context.Dishes
                               where d.Breakfast == true
                               select d;
   
               //populate candidates with them
               candidates = dishes.ToArray();
   
               //if users changed dish type (breakfast or not)
               if (!lastBreakfast)
               {
                   lastBreakfast = true;
   
                   //reset index for last dish
                   lastDish = -1;
               }
           }
           //lunch or dinner
           else
           {
               //get dishes for lunch or dinner
               var dishes = from d in _context.Dishes
                               where d.Breakfast == false
                               select d;
   
               //populate candidates with them
               candidates = dishes.ToArray();
   
               //if users changed dish type (breakfast or not)
               if (lastBreakfast)
               {
                   lastBreakfast = false;
   
                   //reset index for last dish
                   lastDish = -1;
               }
           }
       }
       catch (Exception ex)
       {
           MessageBox.Show(ex.Message);
           return;
       }
   
       //when no dish in database for selected dish type (breakfast or not)
       if (candidates.Length == 0)
       {
           MessageBox.Show("Please add dishes first.");
           return;
       }
   
       //get random int for dish index
       Random random = new Random();
       int index = random.Next(0, candidates.Length);
   
       //make sure users do not same dish right after
       if(candidates.Length > 1)
       {
           while(lastDish == index)
           {
               index = random.Next(0, candidates.Length);
           }
       }
   
       //set lastDish with current one
       lastDish = index;
   
       //display to users
       suggestionTxt.Text = "How about " + candidates[index].Name + "?";
   }
   

4. Go to SingleSuggestion.xaml file.
5. Add Click="getSuggestionBtn_Click" for getSuggestionBtn button.

Check Your Code

After following this chapter, your app should be able to:

• Suggest a random dish, not getting the same one as the previous run if possible (more than 1 dish in the database) on the SingleSuggestion window.