//java文件
package com.example.helloworld;import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.TextureView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;public class MainActivity<Button> extends Activity {Button b;TextView t;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);b=(Button) this.findViewById(R.id.button1);t=(TextView) this.findViewById(R.id.textView1);((View) b).setOnClickListener(new OnClickListener(){public void onClick(View v){t.setText("Hello World");}});}
}

<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=".MainActivity" ><TextViewandroid:id="@+id/textView1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="" /><Buttonandroid:id="@+id/button1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_below="@+id/textView1"android:layout_centerHorizontal="true"android:layout_marginTop="134dp"android:text="来点我" /></RelativeLayout>