Android计算器简单版

一、布局文件main.xml

  <?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"
    >
 <TextView 
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
     android:text="@string/hello"
     />
 <EditText
     android:id="@+id/number1"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
 />
 <RadioGroup
     android:id="@+id/RadioGroup_choice"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:orientation="horizontal"
     android:layout_x="3px"
     android:layout_y="54px"
 >
     <RadioButton
          android:id="@+id/add_RadioButton"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_marginRight="10px"
          android:text="+"
     />
     <RadioButton
          android:id="@+id/jian_RadioButton"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_marginRight="10px"
          android:text="-"
     />
     <RadioButton
          android:id="@+id/cheng_RadioButton"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_marginRight="10px"
          android:text="*"
     />
     <RadioButton
          android:id="@+id/chu_RadioButton"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_marginRight="10px"
          android:text="/"
     />
 </RadioGroup>
 <EditText
     android:id="@+id/number2"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
 />
 <Button
     android:id="@+id/resultButton"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
     android:text="结果"
 />
 <TextView
     android:id="@+id/resultTextView"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
 />
</LinearLayout>

二、android代码功能实现

package com.cn.android;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.TextView;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
 
 private EditText number1 = null;
 private EditText number2 = null;
 private Button resultButton = null;
 private TextView resultTextView = null;
 private RadioGroup mRadioGroup = null;
 private RadioButton jiaRadioButton,jianRadioButton,chengRadioButton,chuRadioButton;
 private String yunsuan;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        number1 = (EditText)findViewById(R.id.number1);
        number2 = (EditText)findViewById(R.id.number2);
        resultButton = (Button)findViewById(R.id.resultButton);
        mRadioGroup = (RadioGroup)findViewById(R.id.RadioGroup_choice);
        jiaRadioButton = (RadioButton)findViewById(R.id.add_RadioButton);
        jianRadioButton = (RadioButton)findViewById(R.id.jian_RadioButton);
        chengRadioButton = (RadioButton)findViewById(R.id.cheng_RadioButton);
        chuRadioButton = (RadioButton)findViewById(R.id.chu_RadioButton);
        resultTextView = (TextView)findViewById(R.id.resultTextView);
       
        mRadioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener(){

   public void onCheckedChanged(RadioGroup arg0, int arg1) {
    // TODO Auto-generated method stub
    if(arg1 == jiaRadioButton.getId()){
     yunsuan = "+";
    }
    else if(arg1 == jianRadioButton.getId()){
     yunsuan = "-";
    }
    else if(arg1 == chengRadioButton.getId()){
     yunsuan = "*";
    }
    else if(arg1 == chuRadioButton.getId()){
     yunsuan = "/";
    }
   }
         
        });
       
        resultButton.setOnClickListener(new OnClickListener(){

   public void onClick(View arg0) {
    
    // TODO Auto-generated method stub
    String num1 = number1.getText().toString();
    String num2 = number2.getText().toString();
    final double dnum1 = Double.parseDouble(num1);
    final double dnum2 = Double.parseDouble(num2);
    
    double resultNum = 0.0;
    
    if(yunsuan.equals("+")){
     resultNum = dnum1 + dnum2;
    }
    else if(yunsuan.equals("-")){
     resultNum = dnum1 - dnum2;
    }
    else if(yunsuan.equals("*")){
     resultNum = dnum1 * dnum2;
    }
    else if(yunsuan.equals("/")){
     resultNum = dnum1 / dnum2;
    } 
    String resultString = String.valueOf(resultNum);
    resultTextView.setText(resultString);
   } 
        });
    }
}