Introduction 
My previous article was Convert Decimal to Binary Number and in this article I explain how to convert a number expressed as a binary number to a number expressed as a decimal number. So let us first of all understand the conversion. 
Binary Number: A number expressed using the base 2 number with digits 0 and 1.
Decimal Number: A number expressed using the 10 number with digits 0 to 9.
Conversion Example: Suppose we want to convert binary number 1101 to decimal. The followiing is the conversion process:
Step 1: 1* 1=1
Step 2: 0* 2=0
Step 3: 1*4=4
Step 4: 1*8=8
Its decimal value = 1 + 0 + 4 + 8 = 13.
So (1101)2  =  (13)10
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
![new-windows-store-app.jpg]()
Step 2
Write the following XAML code in "Mainpage.Xaml" (that is available in Solution Explorer):
<Page
    x:Class="binary_to_decimal_convertor_app.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:binary_to_decimal_convertor_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="313*"/>
            <ColumnDefinition Width="254*"/>
            <ColumnDefinition Width="788*"/>
        </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="Binary to Decimal Converter app" Grid.ColumnSpan="3" Grid.Row="1" Foreground="White" FontSize="20" FontFamily="Arial" TextAlignment="Center"></TextBlock>
        <TextBlock Text="Enter Binary Number :" FontFamily="Arial" FontSize="15" Foreground="White" Grid.Column="1" Grid.Row="2" Grid.RowSpan="4"></TextBlock>
        <TextBox x:Name="textbox1" Grid.Column="2" Grid.Row="2" Width="200" HorizontalAlignment="Left" Height="20" VerticalAlignment="Top" />
        <TextBlock Text="Eqivalent Decimal Number " FontSize="15" Foreground="White" Grid.Column="1" Grid.Row="3"></TextBlock>
        <TextBlock x:Name="text1" FontSize="15" Foreground="White" Grid.Column="2" Grid.Row="3" Width="200" HorizontalAlignment="Left" ></TextBlock>
        <Button x:Name="button1" Grid.Column="2" Grid.Row="4" Background="Yellow" Foreground="Black" Width="150" Content="Click" Click="button1_Click"></Button>
 
    </Grid>
</Page>
Step 3
Now write the following C# code for the button within "Mainpage.Xaml.cs".
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
 
namespace binary_to_decimal_convertor_app
{
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
        }
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
        }
        private void button1_Click(object sender, RoutedEventArgs e)
        {
            long binum=0;
            int r=0, j=1;
            int decnum=0;
            binum =long.Parse(textbox1 .Text );
            while (binum !=0)
            {
                r= (int) binum % 10;
                decnum =decnum +r*j;
                j=j*2;
                binum =binum /10;
            }
            text1 .Text =decnum .ToString ();
        }
    }
}
Step 4
Now Run your app.
![output-of-decimal-app.jpg]()