package com.example.calculator;

import java.util.Random;

import android.os.Bundle;

import android.app.ActionBar;

import android.app.Activity;

import android.content.Intent;

import android.view.Menu;

import android.view.MenuItem;

import android.widget.Button;

import android.widget.RadioButton;

import android.widget.TextView;

public class ChoiceActivity extends Activity {

	private TextView text1,text2,text3;

	private RadioButton radioButton1,radioButton2,radioButton3,radioButton4;

	private Button btn;

	private final Random num1=new Random();

	private final Random num2=new Random();

	private final Random r = new Random();

	private int x1;

	private int x2;

	private int x3;

	private char[] ch={'+','-','*','/'}; //字符数组

	private int index = r.nextInt(ch.length); //随机数，小于数组的长度数, 0~3

	private char d=ch[index];

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		ActionBar actionBar=getActionBar();

		actionBar.setDisplayShowHomeEnabled(true);

		actionBar.setDisplayHomeAsUpEnabled(true);

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_choice);

		text1=(TextView)findViewById(R.id.textView1);

		text2=(TextView)findViewById(R.id.textView2);

		text3=(TextView)findViewById(R.id.textView3);

		radioButton1=(RadioButton)findViewById(R.id.radioButton1);

		radioButton2=(RadioButton)findViewById(R.id.radioButton2);

		radioButton3=(RadioButton)findViewById(R.id.radioButton3);

		radioButton4=(RadioButton)findViewById(R.id.radioButton4);

		btn=(Button)findViewById(R.id.button1);

		final String a=String.valueOf(num1.nextInt(100));

		x1=Integer.valueOf(a);

		final String b=String.valueOf(num2.nextInt(100));

		x2=Integer.valueOf(b);

		final String e=String.valueOf(d);

		text1.setText(a);

		text3.setText(b);

		text2.setText(e);

		radioButton1.setText(a);

		radioButton2.setText(b);

	}

	@Override

	public boolean onCreateOptionsMenu(Menu menu) {

		// Inflate the menu; this adds items to the action bar if it is present.

		getMenuInflater().inflate(R.menu.choice, menu);

		return true;

	}

	@Override

	public boolean onOptionsItemSelected(MenuItem item) {

		// TODO Auto-generated method stub

		switch (item.getItemId()) {

		case android.R.id.home:

			//创建启动MainActivity的Intent

			Intent intent=new Intent(this,TypesActivity.class);

			//添加额外的Flag，将Activity栈中处于MainActivity之上的Activity弹出

			intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

			startActivity(intent);

			break;

		default:

			break;

		}

		return super.onOptionsItemSelected(item);

	}

}

<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"

    android:background="@drawable/animal"

    tools:context=".ChoiceActivity" >

    <TextView

        android:id="@+id/textView1"

        android:layout_width="50dp"

        android:layout_height="wrap_content"

        android:layout_marginTop="100dp" />

    <TextView

        android:id="@+id/textView2"

        android:layout_width="30dp"

        android:layout_height="wrap_content"

        android:layout_alignBaseline="@+id/textView1"

        android:layout_alignBottom="@+id/textView1"

        android:layout_toRightOf="@+id/textView1" />

    <TextView

        android:id="@+id/textView3"

        android:layout_width="50dp"

        android:layout_height="wrap_content"

        android:layout_alignBaseline="@+id/textView2"

        android:layout_alignBottom="@+id/textView2"

        android:layout_toRightOf="@+id/textView2" />

    <TextView

        android:id="@+id/textView4"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignBaseline="@+id/textView3"

        android:layout_alignBottom="@+id/textView3"

        android:layout_toRightOf="@+id/textView3"

        android:text="=" />

    <RadioButton

        android:id="@+id/radioButton2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/radioButton1"

        android:layout_centerVertical="true" />

    <RadioButton

        android:id="@+id/radioButton3"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/textView3"

        android:layout_below="@+id/radioButton2" />

    <RadioButton

        android:id="@+id/radioButton4"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/radioButton3"

        android:layout_below="@+id/radioButton3" />

    <Button

        android:id="@+id/button1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/radioButton4"

        android:layout_centerHorizontal="true"

        android:layout_marginTop="46dp"

        android:text="确定" />

    <RadioButton

        android:id="@+id/radioButton1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_above="@+id/radioButton2"

        android:layout_toLeftOf="@+id/button1" />

</RelativeLayout>