using System;using Android.App;using Android.Content;using Android.Runtime;using Android.Views;using Android.Widget;using Android.OS;namespace HelloDroid{    [Activity(Label = "HelloDroid", MainLauncher = true, Icon = "@drawable/icon")]    public class MainActivity : Activity    {        int count = 1;        protected override void OnCreate(Bundle bundle)        {            base.OnCreate(bundle);            // Set our view from the "main" layout resource            SetContentView(Resource.Layout.Main);            // Get our button from the layout resource,            // and attach an event to it            Button button = FindViewById<Button>(Resource.Id.MyButton);            button.Click += delegate { button.Text = string.Format("{0} clicks!", count++); };        }    }}

package com.example.helloworld;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }}

<?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">    <Button        android:id="@+id/MyButton"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="@string/Hello" /></LinearLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.helloworld.MainActivity" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="@string/hello_world" /></RelativeLayout>