Working With Arithmetic Operators In Android And UWP Using Xamarin.Forms

Introduction

Xamarin is a platform that allows us to create a multi-platform app for Android, Windows, and iOS through a single integrated development environment (IDE) with Xamarin.Form. The interface design for all three platforms can be accomplished within its XAML-based standard, native user-interfaces control.

Let's start.

Step 1

Open Visual Studio and go to New Project >> Installed>> Visual C# >> Cross-Platform.

Picker Working Arithmetic Operators Android UWP Using Xamarin.Forms

Select the Cross- Platform app, then give your project a name and location.

Step 2

Open Solution Eplorerer >> Project Name (Portable) >> App.xaml.cs >> double-click will open the design view of this page.

The code is given below.

C# Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
namespace Picker
{
public partial class App : Application
{
public App()
{
InitializeComponent();
MainPage = new NavigationPage (new MainPage());
}
protected override void OnStart()
{
// Handle when your app starts
}
protected override void OnSleep()
{
// Handle when your app sleeps
}
protected override void OnResume()
{
// Handle when your app resumes
}
}
}

Step 3

Next, open Solution Explorer >> Project Name (Portable) >>Right-Click >> Add >> New Item or Ctrl+Shift+A.

A new dialogue box will open. Now, add the XAML Page and give it a name. Click the "Add" button.

Step 4

Open Solution Explorer >> Project Name >> MainPage.xaml. Open the design view of this page.

The code is given below.

XAML Code

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:Picker"
x:Class="Picker.MainPage">
<ContentPage.Content>
<StackLayout>
<Button Text="Picker" Clicked="Button_Clicked"/>
</StackLayout>
</ContentPage.Content>
</ContentPage>

Step 5

Open Solution Explorer >> Project Name >> MainPage.xaml.cs. Open the design view of this page.

The code is given below.

C# Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
namespace Picker
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
}
async private void Button_Clicked(object sender, EventArgs e)
{
await Navigation.PushAsync(new Page1());
}
}
}

Step 6

Open Solution Explorer >> Project Name >> Page1.xaml. Open the design view of this page.

The code is given below.

XAML Code

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="Picker.Page1">
<ContentPage.Content>
<StackLayout Orientation="Vertical">
<Entry Placeholder="Enter Number 1" x:Name="No1"/>
<Entry Placeholder="Enter Number 2" x:Name="No2"/>
<Label Text="Select Operation" FontSize="Medium"/>
<Picker x:Name="Pk" SelectedIndexChanged="Pk_SelectedIndexChanged"/>
<Label Text="------" x:Name="mylab"/>
</StackLayout>
</ContentPage.Content>
</ContentPage>

Step 7

Open Solution Explorer >> Project Name >> Page.xaml.cs. Open the design view of this page.

The code is given below.

C# Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace Picker
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class Page1 : ContentPage
{
public Page1()
{
InitializeComponent();
Pk.Items.Add("Addition");
Pk.Items.Add("Subtraction");
Pk.Items.Add("Multiplication");
Pk.Items.Add("Divition");
}
private void Pk_SelectedIndexChanged(object sender, EventArgs e)
{
string op = Pk.SelectedItem.ToString();
int n1 = Int32.Parse(No1.Text);
int n2 = Int32.Parse(No2.Text);
double res = 0;
if (op == "Addition")
res = n1 + n2;
else if (op == "Subtraction")
res = n1 - n2;
else if (op == "Multiplication")
res = n1 * n2;
else if (op == "Divition")
res = n1 / n2;
mylab.Text = res + "";
}
}
}

Step 8

Next, select the "Build and Deploy" option followed by selecting from the list Android emulator and simulator. you can choose any API (Application Program Interface) level emulator or simulator to run it.

Output

After a few seconds, you will see your app working.

Android Output

You can choose the Android platform.