结对编程实践小项目

package com.example.mldemo;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class SecondActivity extends Activity {

    private ArrayList<String> operations=new ArrayList<String>();
    private ArrayAdapter<String> numadapter;
    private ListView lv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        // 取出mainactivity传递过来的数据
        Intent intent = getIntent();
        int num2 = intent.getIntExtra("data", -1);

        lv = (ListView) findViewById(R.id.listView1);
        for (int i = 0; i < num2; i++) {
            operations.add(operation());
        }

        numadapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, operations);

        lv.setAdapter(numadapter);

    }

    public String operation() {

        int randomNum1; // 随机数第一个值
        int randomNum2; // 随机数第二个值

        String operation = null;
        int operator;// 运算符

        operator = (int) (Math.random() * 4);
        randomNum1 = (int) (Math.random() * 100 + 1);
        randomNum2 = (int) (Math.random() * 100 + 1);
        // 通过if语句判断
        if (operator == 0) {
            operation = (randomNum1 + "+" + randomNum2 + "=").toString();
        }

        if (operator == 1) {
            operation = (randomNum1 + "-" + randomNum2 + "=").toString();
        }

        if (operator == 2) {
            operation = (randomNum1 + "*" + randomNum2 + "=").toString();
        }

        if (operator == 3) {
            
        
                operation = (randomNum1 + "/" + randomNum2 + "=").toString();
        

        }

        return operation;
    }

}