Android计算器

在学习安卓，做个计算器练手。

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">计算器</string>
    <string name="app_name">计算器</string>
    <string name="one">1</string>
    <string name="two">2</string>
    <string name="three">3</string>
    <string name="four">4</string>
    <string name="five">5</string>
    <string name="six">6</string>
    <string name="seven">7</string>
    <string name="eight">8</string>
    <string name="nine">9</string>
    <string name="zero">0</string>
    <string name="jia">+</string>
    <string name="jian">-</string>
    <string name="cheng">x</string>
    <string name="chu">÷</string>
    <string name="dengyu">=</string>
    <string name="zhengfu">+/-</string>
    <string name="dihao">.</string>
    <string name="ping">x²</string>
    <string name="kai">√x</string>
    <string name="shanchu">清除</string>
    <string name="shan">归零</string>
</resources>

main.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout 
    android:background="#ff808080" 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical"
    android:layout_gravity="center_vertical" android:id="@+id/zhengfu">
        
        <EditText 
        android:text="TextView" 
        android:id="@+id/textView1" 
        android:textSize="25sp"
        android:textColor="#000000" 
        android:layout_gravity="center"
        android:gravity="left"
        android:cursorVisible="false"
        android:editable = "false" 
        android:layout_height="wrap_content" 
        android:layout_width="fill_parent" 
        android:layout_marginLeft="4dip" 
        android:layout_marginRight="4dip" 
        android:layout_marginTop="4dip" android:layout_weight="1.5">
        </EditText>
        
        <TableLayout
        android:id="@+id/tablelayout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="4dip" android:layout_weight="10">
        
        <LinearLayout
        android:id="@+id/linearlayout02"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:layout_weight="1">

        	<Button
        	    android:id="@+id/button_c"
        	    android:layout_width="50dip"
        	    android:layout_height="fill_parent"
        	    android:layout_weight="1"
        	    android:text="@string/shan"
        	    android:textSize="25sp" >

        	</Button>

       	<Button
        	    android:id="@+id/button_ce"
        	    android:layout_width="50dip"
        	    android:layout_height="fill_parent"
        	    android:layout_weight="1"
        	    android:text="@string/shanchu"
        	    android:textSize="25sp" >

        	</Button>
        </LinearLayout>
        	<TableRow
        	android:id="@+id/row0"
        	android:layout_width="fill_parent"
        	android:layout_height="fill_parent"
        	android:layout_weight="1">
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/one" android:id="@+id/button1">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/two" android:id="@+id/button2">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/three" android:id="@+id/button3">
        		</Button>

        		<Button
        		    android:id="@+id/button_add"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/jia"
        		    android:textSize="25sp" >

        		</Button>
        	</TableRow>
        	
        	<TableRow
        	android:id="@+id/row1"
        	android:layout_width="fill_parent"
        	android:layout_height="fill_parent"
        	android:layout_weight="1">
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/four" android:id="@+id/button4">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/five" android:id="@+id/button5">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/six" android:id="@+id/button6">
        		</Button>

        		<Button
        		    android:id="@+id/button_minus"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/jian"
        		    android:textSize="25sp" >

        		</Button>
        	</TableRow>
        	
        	<TableRow
        	android:id="@+id/row2"
        	android:layout_width="fill_parent"
        	android:layout_height="fill_parent"
        	android:layout_weight="1">
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/seven" android:id="@+id/button7">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/eight" android:id="@+id/button8">
        		</Button>
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/nine" android:id="@+id/button9">
        		</Button>

        		<Button
        		    android:id="@+id/button_multiply"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/cheng"
        		    android:textSize="25sp" >

        		</Button>
       	 	 </TableRow>
        	
        	<TableRow
        	android:id="@+id/row3"
        	android:layout_width="fill_parent"
        	android:layout_height="fill_parent"
        	android:layout_weight="1">
        		<Button
        		android:layout_width="40dip"
        		android:layout_height="fill_parent"
        		android:layout_weight="1"
        		android:textSize="25sp" android:text="@string/zero" android:id="@+id/button0">
        		</Button>

        		<Button
        		    android:id="@+id/button_dot"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/dihao"
        		    android:textSize="25sp" >

        		</Button>

        		<Button
        		    android:id="@+id/button_equals"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/dengyu"
        		    android:textSize="25sp" >

        		</Button>

        		<Button
        		    android:id="@+id/button_divide"
        		    android:layout_width="40dip"
        		    android:layout_height="fill_parent"
        		    android:layout_weight="1"
        		    android:text="@string/chu"
        		    android:textSize="25sp" >

        		</Button>
       	  </TableRow>
        <LinearLayout
        android:id="@+id/tableRow1" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:orientation="horizontal"
        android:layout_weight="1">

           <Button
               android:id="@+id/button_zhengfu"
               android:layout_width="50dp"
               android:layout_height="fill_parent"
               android:layout_weight="1"
               android:text="@string/zhengfu"
               android:textSize="25sp" >

           </Button>

           <Button
               android:id="@+id/button_pingfang"
               android:layout_width="50dp"
               android:layout_height="fill_parent"
               android:layout_weight="1"
               android:text="@string/ping"
               android:textSize="25sp" >

           </Button>

           <Button
               android:id="@+id/button_kaifang"
               android:layout_width="50dp"
               android:layout_height="fill_parent"
               android:layout_weight="1"
               android:text="@string/kai"
               android:textSize="25sp" >

           </Button>

        </LinearLayout>
       </TableLayout>
    </LinearLayout>

CalculaterActivity.java

package com.fuxing;

import fuxing.calculater.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.*;
import android.widget.*;

public class CalculaterActivity extends Activity {

	String str="";
	EditText et;
	char ch=' ';//计算符号,+，-,*,/
	int flag=0;
	double b=0.0,g=0.0,f=0.0;
	View vi;
	
	//菜单项退出 
	public boolean onCreateOptionsMenu(Menu menu){
		menu.add(0, 1, 1, "退出");
		return super.onCreateOptionsMenu(menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		if(item.getItemId()==1){finish();}
		return super.onOptionsItemSelected(item);
	}

	//计算
	public double calculater(){
		switch(ch){
		case ' ':f=g;break;
		case '+':f=b+g;break;
		case '-':f=b-g;break;
		case '*':f=b*g;break;
		case '/':f=b/g;break;
		}
		b=f;
		ch=' ';
		return f;
	}
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        //获得按键
        final Button number[]=new Button[10];
		final Button button_add=(Button)findViewById(R.id.button_add);//+
		final Button button_minus=(Button)findViewById(R.id.button_minus);//-
		final Button button_multiply=(Button)findViewById(R.id.button_multiply);//*
		final Button button_divide=(Button)findViewById(R.id.button_divide);//除
		final Button button_equals=(Button)findViewById(R.id.button_equals);//等于
		final Button button_dot=(Button)findViewById(R.id.button_dot);//点
		final Button button_ce=(Button)findViewById(R.id.button_ce);//清除
		final Button button_c=(Button)findViewById(R.id.button_c);//归零
		final Button button_zhengfu=(Button)findViewById(R.id.button_zhengfu);//正负号
		final Button button_kaifang=(Button)findViewById(R.id.button_kaifang);//开方
		final Button button_pingfang=(Button)findViewById(R.id.button_pingfang);//平方
	    //数字键0-9
		number[0]=(Button)findViewById(R.id.button0);
		number[1]=(Button)findViewById(R.id.button1);
		number[2]=(Button)findViewById(R.id.button2);
		number[3]=(Button)findViewById(R.id.button3);
		number[4]=(Button)findViewById(R.id.button4);
		number[5]=(Button)findViewById(R.id.button5);
		number[6]=(Button)findViewById(R.id.button6);
		number[7]=(Button)findViewById(R.id.button7);
		number[8]=(Button)findViewById(R.id.button8);
		number[9]=(Button)findViewById(R.id.button9);
        
        et=(EditText) findViewById(R.id.textView1);

        et.setText(str);
        
        //数字按键0-9       
        number[0].setOnClickListener(new View.OnClickListener() {		
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=0;
					et.setText(str);
					flag=0;
					}
				 else{
					char ch1[];
					ch1=str.toCharArray();
					if(!(ch1.length==1&&ch1[0]=='0'))
					{str+=0;
					et.setText(str);}
					
				 }
				vi=v;
			}
		});
               
        number[1].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=1;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=1;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[2].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=2;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=2;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[3].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=3;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=3;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[4].setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=4;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=4;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[5].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=5;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=5;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[6].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=6;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=6;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[7].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=7;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=7;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[8].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=8;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=8;
					et.setText(str);
				 }
				vi=v;
			}
		});

        number[9].setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(flag==1){
					str="";
					str+=9;
					et.setText(str);
					flag=0;
					}
				 else{
					str+=9;
					et.setText(str);
				 }
				vi=v;
			}
		});

        //设定符号键        

        //加
        button_add.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				if(vi==button_add||vi==button_minus||vi==button_multiply||vi==button_divide){
					ch='+';
				}
				
				else{
					g=Double.parseDouble(str);
					calculater();
					str=""+f;
					et.setText(str);
					ch='+';
					flag=1;
					vi=v;
				}}
			}
		});

        //减
        button_minus.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				if(vi==button_add||vi==button_minus||vi==button_multiply||vi==button_divide){
					ch='-';
				}
				
				else{
					g=Double.parseDouble(str);
					calculater();
					str=""+f;
					et.setText(str);
					ch='-';
					flag=1;
					vi=v;
				}}
			}
		});

        //乘
        button_multiply.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				if(vi==button_add||vi==button_minus||vi==button_multiply||vi==button_divide){
					ch='*';
				}
				
				else{
					g=Double.parseDouble(str);
					calculater();
					str=""+f;
					et.setText(str);
					ch='*';
					flag=1;
					vi=v;
				}}
			}
		});

        //除
        button_divide.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				if(vi==button_add||vi==button_minus||vi==button_multiply||vi==button_divide){
					ch='/';
				}
				
				else{
					g=Double.parseDouble(str);
					calculater();
					str=""+f;
					et.setText(str);
					ch='/';
					flag=1;
					vi=v;
				}}
			}
		});

        //等号        
        button_equals.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""&&vi!=button_add&&vi!=button_minus&&vi!=button_multiply&&vi!=button_divide){
					g=Double.parseDouble(str);
					calculater();
					str=""+f;
					et.setText(str);
					flag=1;
					vi=v;

				}
			}
		});
    
        //小数点
        button_dot.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str==""){
					str+="";
					et.setText(str);
				}
				else{
					char ch1[];int x=0;
					ch1=str.toCharArray();
					for(int i=0;i<ch1.length;i++)
						if(ch1[i]=='.')
							x++;
					if(x==0){
						str+=".";
						et.setText(str);
					}
				}

			}
		});
        
        //清除
        button_ce.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				str="";
				et.setText(str);
				vi=v;

			}
		});
        //归零
        button_c.setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				b=0.0;ch=' ';g=0.0;
				str="";
				et.setText(str);

			}
		});
        //正负号处理
        button_zhengfu.setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				if(vi!=button_dot&&str!=""){
					char ch=str.charAt(0);
					if(ch=='-')
						str=str.replace("-","");
					else
						str="-"+str;
					et.setText(str);
				}
			}
		});
        //开方
        button_kaifang.setOnClickListener(new View.OnClickListener() {
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				double a=Double.parseDouble(str);
				str=Math.sqrt(a)+"";
				et.setText(str);
			}}
		});
        //平方
        button_pingfang.setOnClickListener(new View.OnClickListener() {
			
			public void onClick(View v) {
				// TODO Auto-generated method stub
				if(str!=""){
				double a=Double.parseDouble(str);
				str=""+a*a;
				et.setText(str);
			}}
		});
    }
}