проблема с WPF

[programming]

В целом, есть программа, которая состоит из grid и кнопочек. при нажатии на кнопочки часть ячеек становится видимой и отображает какую-то букву.

как-то так

ну это просто
но вот препод дал задание сделать такую кнопку, что бы при нажатии на нее блоки постепенно становились видимыми - например по столбцам справа налево.
пробовала в c# часть запихнуть Thread.Sleep(x);, но тогда получается что просто программа ждет сколько-то секунд а затем сразу заполняет все ячейки. ничего другого не придумала О_о дуб я. подскажите в каком направлении искать) заранее спасибо)

код, много кода

xaml часть

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="БЕССОНОВА Т.И. гр.036" Height="450" Width="642">

    <Grid>
        <Grid Name="Gr" Width="380" Margin="121,35,133,87" DataContext="{Binding}">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="20*" />
                <ColumnDefinition Width="20*" />
                <ColumnDefinition Width="20*" />
                <ColumnDefinition Width="20*" />
                <ColumnDefinition Width="20*" />
                <ColumnDefinition Width="20*" />
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="30*"/>
                <RowDefinition Height="30*"/>
                <RowDefinition Height="30*"/>
                <RowDefinition Height="30*"/>
                <RowDefinition Height="30*"/>
                <RowDefinition Height="30*"/>

            </Grid.RowDefinitions>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect1" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect2" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect3" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect4" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect5" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect6" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="0"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect7" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect8" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect9" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect10" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect11" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect12" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="1"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect13" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect14" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect15" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect16" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect17" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect18" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="2"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect19" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect20" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect21" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect22" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect23" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect24" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="3"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect25" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect26" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect27" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect28" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect29" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect30" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="4"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect31" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="0" Grid.Row="5"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect32" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="1" Grid.Row="5"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect33" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="2" Grid.Row="5"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect34" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="3" Grid.Row="5"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect35" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="4" Grid.Row="5"/>
            <Rectangle HorizontalAlignment="Stretch" Name="Rect36" Fill="Black" Stroke="Black" VerticalAlignment="Stretch" Visibility="Hidden"  Grid.Column="5" Grid.Row="5"/>


        </Grid>
        <Button Content="Б" Height="50" HorizontalAlignment="Left" Margin="77,349,0,0" Name="button1" VerticalAlignment="Top" Width="50" Click="btnB_Click" />
        <Button Content="E" Height="50" HorizontalAlignment="Left" Margin="147,349,0,0" Name="button2" VerticalAlignment="Top" Width="50" Click="btnE_Click"/>
        <Button Content="С" Height="50" HorizontalAlignment="Left" Margin="217,349,0,0" Name="button3" VerticalAlignment="Top" Width="50" Click="btnS_Click"/>
        <Button Content="O" Height="50" HorizontalAlignment="Left" Margin="287,349,0,0" Name="button4" VerticalAlignment="Top" Width="50" Click="btnO_Click"/>
        <Button Content="Н" Height="50" HorizontalAlignment="Left" Margin="357,349,0,0" Name="button5" VerticalAlignment="Top" Width="50" Click="btnN_Click"/>
        <Button Content="В" Height="50" HorizontalAlignment="Left" Margin="427,349,0,0" Name="button6" VerticalAlignment="Top" Width="50" Click="btnV_Click"/>
        <Button Content="А" Height="50" HorizontalAlignment="Left" Margin="497,349,0,0" Name="button7" VerticalAlignment="Top" Width="50" Click="btnA_Click"/>
        <Button Content="*" Height="50" HorizontalAlignment="Left" Margin="533,156,0,0" Name="button8" VerticalAlignment="Top" Width="50" Click="btnX_Click"/>
    </Grid>

</Window>

c#-часть

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Threading;

namespace WpfApplication2
{
    /// <summary>
    /// Логика взаимодействия для MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        
        private void Refresh()
        {
            #region VisibilityHidden
            Rect1.Visibility = Visibility.Hidden;
            Rect2.Visibility = Visibility.Hidden;
            Rect3.Visibility = Visibility.Hidden;
            Rect4.Visibility = Visibility.Hidden;
            Rect5.Visibility = Visibility.Hidden;
            Rect6.Visibility = Visibility.Hidden;
            Rect7.Visibility = Visibility.Hidden;
            Rect8.Visibility = Visibility.Hidden;
            Rect9.Visibility = Visibility.Hidden;
            Rect10.Visibility = Visibility.Hidden;
            Rect11.Visibility = Visibility.Hidden;
            Rect12.Visibility = Visibility.Hidden;
            Rect13.Visibility = Visibility.Hidden;
            Rect14.Visibility = Visibility.Hidden;
            Rect15.Visibility = Visibility.Hidden;
            Rect16.Visibility = Visibility.Hidden;
            Rect17.Visibility = Visibility.Hidden;
            Rect18.Visibility = Visibility.Hidden;
            Rect19.Visibility = Visibility.Hidden;
            Rect20.Visibility = Visibility.Hidden;
            Rect21.Visibility = Visibility.Hidden;
            Rect22.Visibility = Visibility.Hidden;
            Rect23.Visibility = Visibility.Hidden;
            Rect24.Visibility = Visibility.Hidden;
            Rect25.Visibility = Visibility.Hidden;
            Rect26.Visibility = Visibility.Hidden;
            Rect27.Visibility = Visibility.Hidden;
            Rect28.Visibility = Visibility.Hidden;
            Rect29.Visibility = Visibility.Hidden;
            Rect30.Visibility = Visibility.Hidden;
            Rect31.Visibility = Visibility.Hidden;
            Rect32.Visibility = Visibility.Hidden;
            Rect33.Visibility = Visibility.Hidden;
            Rect34.Visibility = Visibility.Hidden;
            Rect35.Visibility = Visibility.Hidden;
            Rect36.Visibility = Visibility.Hidden;
            #endregion
        }
        private void btnB_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_B();
        }
        private void btnE_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_E();
        }
        private void btnS_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_S();
        }
        private void btnO_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_O();
        }
        private void btnN_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_N();
        }
        private void btnV_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_V();
        }
        private void btnA_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_A();
        }
        private void btnX_Click(object sender, RoutedEventArgs e)
        {
            Refresh();
            Print_1();
            
            Print_2();
            Print_3();
        }
        private void Print_O()
        {
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect17.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
        }

        private void Print_S() 
        {
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
        }

        private void Print_B()
        {
            Rect2.Visibility = Visibility.Visible;
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect5.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect15.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect17.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
            Rect35.Visibility = Visibility.Visible;
        }

        private void Print_E() 
        {
            Rect2.Visibility = Visibility.Visible;
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect5.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect15.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
            Rect35.Visibility = Visibility.Visible;
        }

        private void Print_V() 
        {
            Rect2.Visibility = Visibility.Visible;
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect15.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
        }

        private void Print_A() 
        {
            Rect4.Visibility = Visibility.Visible;
            Rect5.Visibility = Visibility.Visible;
            Rect9.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect17.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect21.Visibility = Visibility.Visible;
            Rect22.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect35.Visibility = Visibility.Visible;
        }
         
        private void Print_N()
        {
            Rect2.Visibility = Visibility.Visible;
            Rect5.Visibility = Visibility.Visible;
            Rect8.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect15.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect17.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect35.Visibility = Visibility.Visible;
        }

        private void Print_1()
        {
            Rect1.Visibility = Visibility.Visible;
            Rect2.Visibility = Visibility.Visible;
            Rect3.Visibility = Visibility.Visible;
            Rect4.Visibility = Visibility.Visible;
            Rect5.Visibility = Visibility.Visible;
            Rect6.Visibility = Visibility.Visible;
            Rect7.Visibility = Visibility.Visible;
            Rect12.Visibility = Visibility.Visible;
            Rect13.Visibility = Visibility.Visible;
            Rect18.Visibility = Visibility.Visible;
            Rect19.Visibility = Visibility.Visible;
            Rect24.Visibility = Visibility.Visible;
            Rect25.Visibility = Visibility.Visible;
            Rect30.Visibility = Visibility.Visible;
            Rect31.Visibility = Visibility.Visible;
            Rect32.Visibility = Visibility.Visible;
            Rect33.Visibility = Visibility.Visible;
            Rect34.Visibility = Visibility.Visible;
            Rect35.Visibility = Visibility.Visible;
            Rect36.Visibility = Visibility.Visible;
        }
        private void Print_2()
        {
            Thread.Sleep(5000);
            Rect8.Visibility = Visibility.Visible;
            Rect9.Visibility = Visibility.Visible;
            Rect10.Visibility = Visibility.Visible;
            Rect11.Visibility = Visibility.Visible;
            Rect14.Visibility = Visibility.Visible;
            Rect17.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect20.Visibility = Visibility.Visible;
            Rect23.Visibility = Visibility.Visible;
            Rect26.Visibility = Visibility.Visible;
            Rect27.Visibility = Visibility.Visible;
            Rect28.Visibility = Visibility.Visible;
            Rect29.Visibility = Visibility.Visible;
        }
        private void Print_3()
        {
            Thread.Sleep(5000);
            Rect15.Visibility = Visibility.Visible;
            Rect16.Visibility = Visibility.Visible;
            Rect21.Visibility = Visibility.Visible;
            Rect22.Visibility = Visibility.Visible;
            
        }
       

    }
}