In this article I am going to describe how to convert octal based number into a binary based number. So first of all I will describe what an octal based number is and what a binary based number is.
Octal Number: A number expressed using the base 8 number system with digits 0 to 7.
Binary Number: A number expressed using the base 2 number with digits 0 and 1.
Use the following procedure to create it.
Step 1
First of all you must create a new Windows Store Application.
Open Visual Studio 2012
"File" -> "New" -> "Project..."
Choose "Template" -> "Visual C#" -> "Window Store app"
Choose "Blank App (XAML)" then rename the application

Step 2
Write the following XAML code in "Mainpage.Xaml" (that is available in Solution Explorer):
<Page
x:Class="octal_to_binary_app.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:octal_to_binary_app"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid Background="red">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="316*"/>
<ColumnDefinition Width="256*"/>
<ColumnDefinition Width="295*"/>
<ColumnDefinition Width="499*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="78*"/>
<RowDefinition Height="49*"/>
<RowDefinition Height="37*"/>
<RowDefinition Height="40*"/>
<RowDefinition Height="39*"/>
<RowDefinition Height="525*"/>
</Grid.RowDefinitions>
<TextBlock Text="Octal to binary Converter app" Grid.ColumnSpan="4" Grid.Row="1" Foreground="White" FontSize="20" FontFamily="Arial" TextAlignment="Center" FontWeight="ExtraBold"></TextBlock>
<TextBlock Text="Entern Octal Number :" FontFamily="Arial" FontSize="15" Foreground="White" Grid.Column="1" Grid.Row="2" Grid.RowSpan="4" FontWeight="ExtraBold"></TextBlock>
<TextBox x:Name="textbox1" Grid.Column="2" Grid.Row="2" Width="200" HorizontalAlignment="Left" Height="20" VerticalAlignment="Top" />
<TextBlock Text="Eqivalent binary Number is " FontSize="15" Foreground="White" Grid.Column="1" Grid.Row="3" FontWeight="ExtraBold"></TextBlock>
<TextBlock x:Name="text1" FontSize="15" Foreground="White" Grid.Column="2" Grid.Row="3" Width="200" HorizontalAlignment="Left" ></TextBlock>

Sam HobbsPosted Feb 22, 2013, 1:50 PM
I thnk the button1_Click method can be simplified as: int i = Convert.ToInt32(textbox1.Text, 8); text1.Text = Convert.ToString(i, 2);