Hello World Application in Xamarin ~ IT Tutorials with Example

Wednesday 3 December 2014

Wednesday, December 03, 2014

Hello World Application in Xamarin

In this Article, We will learn How to create a Simple Hello World Application for Android Device using Xamarin / Mono for Android. Before Starting, I hope you have already installed Xamarin for Android.

Let's Start:
1) Go to File -> New -> Project
2) Select Android Application -> Give it a Name.

Create Hello World Android Application using Xamarin / Mono for Android

Before Starting, Have a look at Solution Explorer. Android Application contains Properties, References, Assets, Resources etc. Properties contains AssemblyInfo (Same as you have seen in C# project). References folder contains Assembly Files (DLL file). Mono.Android DLL assembly contains the C# binding to the Android API.

Resources folder contains Drawable folder(which contains icons and images for the application), Layout (provides designer surface for the application.). Resource.Designer.cs contains Autogenerated Code. As We are going to start from the basics, Delete main.axml Layout and Activity1.cs file from the Project.

3) Right Click on Layout ->Add -> New Item.

Add New layout in Mono for Android / Xamarin

4) Add Android Layout (named as Man.axml) -> Click on Add and Select it.

Android Layout in Xamarin / Mono for Android

5) Drop a Button control from the Toolbox.

Set Button text as Click Me! and id as @+id/btn_Hello.

Main.axml Code:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:minWidth="25px"

android:minHeight="25px">

<Button

android:text="Click Me!"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:id="@+id/btn_Hello" />

</LinearLayout>

6) Add New item -> Select Activity -> Click on Add.

Add Activity in Mono for Android / Xamarin

Activity1.cs Code:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Android.App;

using Android.Content;

using Android.OS;

using Android.Runtime;

using Android.Views;

using Android.Widget;

namespace Hello_World_Application

{

//Set the Label = "Hello World Application" which is displayed on the Top of the Application(in Title)

//Set MainLauncher = true makes this Activity as a Main Activity and Application starts from this Activity.

//Set Icon using Icon = "@drawable/icon"

[Activity(Label = "Hello World Application", MainLauncher = true, Icon = "@drawable/icon")]

public class Activity1 : Activity

{

//Creating Instance of Button

Button btn_Hello;

protected override void OnCreate(Bundle bundle)

{

base.OnCreate(bundle);

//SetContentView

SetContentView(Resource.Layout.Main);

//Get btn_Hello Button control from the Manin.axml Layout.

btn_Hello = FindViewById<Button>(Resource.Id.btn_Hello);

//Creating Click event of btn_Hello

btn_Hello.Click += btn_Hello_Click;

}

//btn_Hello Click Event

void btn_Hello_Click(object sender, EventArgs e)

{

//Display a Toast Message on Clicking the btn_Hello

Toast.MakeText(this, "Hello World Application by Anoop", ToastLength.Short).Show();

}

7) Build and run the Application. Start emulator image if not started. Select the Running devices and then click on OK.

Note: Emulator takes lot of time to startup. Enable USB Debugging on your Android Device and run your Application on Device directly which is much faster as compared to debugging on emulator.