Android开发之简单计算器

运行截图

点击"相加"按钮

ViewActivity.java

package com.archie.activity03;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class ViewActivity extends Activity {
    private TextView textView;
    private EditText editText1;
    private EditText editText2;
    
    private Button btn1;
    private Button btn2;
    private Button btn3;
    private Button btn4;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //编辑框
        editText1=(EditText) findViewById(R.id.numberOne);
        editText2=(EditText) findViewById(R.id.numberTwo);
        
        //文本
        textView=(TextView) findViewById(R.id.textView);
        textView.setText("与");
        //按钮
        btn1=(Button) findViewById(R.id.btn1);
        btn1.setText("相加");
        //绑定监听器对象
        btn1.setOnClickListener(new Btn1CalListener());
        
        btn2=(Button) findViewById(R.id.btn2);
        btn2.setText("相减");
        btn2.setOnClickListener(new Btn2CalListener());
        
        btn3=(Button) findViewById(R.id.btn3);
        btn3.setText("相乘");
        btn3.setOnClickListener(new Btn3CalListener());
        
        btn4=(Button) findViewById(R.id.btn4);
        btn4.setText("相除");
        btn4.setOnClickListener(new Btn3CalListener());
    }
    //加法
    class Btn1CalListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            //获取两个EditText的值
            String numberOne=editText1.getText().toString();
            String numberTwo=editText2.getText().toString();
            //将获取的值存放到Intent对象当中，以便传递
            Intent intent=new Intent();
            intent.putExtra("one", numberOne);
            intent.putExtra("two", numberTwo);
            
            //运算符
            intent.putExtra("calculate", "+");
            
            intent.setClass(ViewActivity.this, ResultActivity.class);
            //启动ResultActivity
            ViewActivity.this.startActivity(intent);
        }
        
    }
    //减法
    class Btn2CalListener implements OnClickListener{

        @Override
        public void onClick(View v) {
            //获取两个EditText的值
            String numberOne=editText1.getText().toString();
            String numberTwo=editText2.getText().toString();
            //将获取的值存放到Intent对象当中，以便传递
            Intent intent=new Intent();
            intent.putExtra("one", numberOne);
            intent.putExtra("two", numberTwo);
            
            //运算符
            intent.putExtra("calculate", "-");
            
            intent.setClass(ViewActivity.this, ResultActivity.class);
            //启动ResultActivity
            ViewActivity.this.startActivity(intent);
        }
        
    }
    //乘法
    class Btn3CalListener implements OnClickListener{
        @Override
        public void onClick(View v) {
            //获取两个EditText的值
            String numberOne=editText1.getText().toString();
            String numberTwo=editText2.getText().toString();
            //将获取的值存放到Intent对象当中，以便传递
            Intent intent=new Intent();
            intent.putExtra("one", numberOne);
            intent.putExtra("two", numberTwo);
            
            //运算符
            intent.putExtra("calculate", "*");
            
            intent.setClass(ViewActivity.this, ResultActivity.class);
            //启动ResultActivity
            ViewActivity.this.startActivity(intent);
        }
    }
    //除法
    class Btn4CalListener implements OnClickListener{
        @Override
        public void onClick(View v) {
            //获取两个EditText的值
            String numberOne=editText1.getText().toString();
            String numberTwo=editText2.getText().toString();
            //将获取的值存放到Intent对象当中，以便传递
            Intent intent=new Intent();
            intent.putExtra("one", numberOne);
            intent.putExtra("two", numberTwo);
            
            //运算符
            intent.putExtra("calculate", "/");
            
            intent.setClass(ViewActivity.this, ResultActivity.class);
            //启动ResultActivity
            ViewActivity.this.startActivity(intent);
        }
    }
}

ResultActivity.java

package com.archie.activity03;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

public class ResultActivity extends Activity{

    private TextView textView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.result);
        textView=(TextView) findViewById(R.id.result);
        
        //得到Intent对象
        Intent intent=getIntent();
        int one=Integer.parseInt(intent.getStringExtra("one"));
        int two=Integer.parseInt(intent.getStringExtra("two"));
        
        String calculate=intent.getStringExtra("calculate");
        int result=0;
        //加法
        if(calculate.equals("+")){
            result=one+two;
            textView.setText(result+"");
        }
        //减法
        else if(calculate.equals("-")){
            result=one-two;
            textView.setText(result+"");
        }
        //乘法
        else if(calculate.equals("*")){
            result=one*two;
            textView.setText(result+"");
        }
        //除法
        else if(calculate.equals("/")){
            try {
                result=one/two;
                textView.setText(result+"");
            } catch (Exception e) {
                textView.setText("除数不能为零");
                e.printStackTrace();
            }
        }
        
    }

    
}