Creating HelloWorld Program in Xamarin.Android
This tutorial explains step by step approach to create and deploy a Xamarin.Android application. For the sake of…
January 7, 2014 · 5 min read
This tutorial explains step by step approach to create and deploy a Xamarin.Android application. For the sake of simplicity our first ever Xamarin.Android application, will have very basic user interface.
1. Creating a Xamarin.Android Application
This example assumes you already have Xamarin.Android installed in your development system. If you are a windows user you can use Visual Studio 2010 Professional or MonoDev IDE for development.
Let us create a new Xamarin.Android solution. Xamarin.Android includes several project templates, including:
- Android Library Project – A reusable .NET library project for Android.
- Android Application – A basic starter project with a single activity.
- Android OpenGL Application – An OpenGL starter project.
We will use “Android Application template” for this example. Let’s create an application by doing the following:
2. Understanding Application Components
In the above section, we have just created a simple Xamarin.Android project. It automatically generates a project structure with different files and folders. The “HelloWorld” project includes three folders named Assets, Properties, and Resources.
- Assets – Contains any type of file the application needs included in its package. Files included here are accessible at runtime via the Assets class.
- Properties – Contains normal .NET assembly metadata.
- Resources – Contains application resources such as strings and images, as well as declarative XML user interface definitions. These resources are accessible through the generated Resource class.
The project template also created a class called HelloWorld in the file MainActivity.cs. An Activity is a class that models a destination where a user can perform some action while using an app, typically via a user interface.
3. Creating HelloWorld program
In this example we will create a simple screen with a TextView and a Button. Clicking the button will show a toast message to user.
Main.axml
<?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:background="#ffe7e5e5">
<TextView
android:text="HelloWorld Example in Xamrin"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/textView1"
android:gravity="center_horizontal"
android:layout_margin="10dp"
android:textColor="#ff130c0c" />
<Button
android:id="@+id/myButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
android:capitalize="characters"
android:layout_margin="10dp"
android:background="#ff0f37f5"
android:textColor="#ffffffff"
android:textSize="18dp"
android:textStyle="bold"
android:typeface="sans" />
</LinearLayout>MainActivity.cs
using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
namespace HelloWorld
{
[Activity (Label = "HelloWorld!", MainLauncher = true)]
public class MainActivity : Activity
{
protected override void OnCreate (Bundle bundle)
{
base.OnCreate (bundle);
// Set your view layout layout resource file
SetContentView (Resource.Layout.Main);
// Initilize button from the layout resource
Button button = FindViewById<Button> (Resource.Id.myButton);
// and attach an event to it
button.Click += delegate {
//display toast message
Toast.MakeText (Application, "Button Clicked!", ToastLength.Short).Show ();
};
}
}
}4. Output
Here is a screenshot that shows the application running in Samsung S4.
