基于android平台开发的计算器

布局文件:

activity_calculator.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/display"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_vertical"
android:background="#ff808080"
android:orientation="vertical" >

<EditText
android:id="@+id/et_show"
android:gravity="right|center_vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginLeft="4dip"
android:layout_marginRight="4dip"
android:layout_marginTop="4dip"
android:layout_weight="1.5"
android:cursorVisible="false"
android:hint="@string/show"
android:textColor="#000000"
android:singleLine="true"
android:textSize="70sp" >
</EditText>

<TableLayout
android:id="@+id/tablelayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="4dip"
android:layout_weight="10" >

<TableRow
android:id="@+id/tableRow2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1.5" >
<Button
android:id="@+id/btnClearAll"
android:layout_width="20dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/clearAll"
android:textSize="25sp"
android:background="#CD3278"
android:textColor="#FFFFFF" >
</Button>
</TableRow>

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

<Button
android:id="@+id/btnPlusOrMinus"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/plusOrminus"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" />

<Button
android:id="@+id/btnSquare"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/square"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" />

<Button
android:id="@+id/btnRadicals"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/radicals"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF">
</Button>

<Button
android:id="@+id/btnClears"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/clears"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" >
</Button>
</LinearLayout>

<TableRow
android:id="@+id/row0"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" >

<Button
android:id="@+id/btnOne"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/one"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnTwo"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/two"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnThree"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/three"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF">
</Button>

<Button
android:id="@+id/btnAdd"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/add"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" >
</Button>
</TableRow>

<TableRow
android:id="@+id/row1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" >

<Button
android:id="@+id/btnFour"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/four"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnFive"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/five"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnSix"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/six"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnMinus"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/minus"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" >
</Button>
</TableRow>

<TableRow
android:id="@+id/row2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" >

<Button
android:id="@+id/btnSeven"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/seven"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnEight"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/eight"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnNine"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/nine"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF" >
</Button>

<Button
android:id="@+id/btnMultiply"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/multiply"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" >
</Button>
</TableRow>

<TableRow
android:id="@+id/row3"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1" >

<Button
android:id="@+id/btnZero"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/zero"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF">
</Button>

<Button
android:id="@+id/btnPoint"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/decimalpoint"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF">
</Button>

<Button
android:id="@+id/btnEqual"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/equal"
android:textSize="25sp"
android:background="#303030"
android:textColor="#FFFFFF">
</Button>

<Button
android:id="@+id/btnDivide"
android:layout_width="40dip"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="@string/divide"
android:textSize="25sp"
android:background="#CD661D"
android:textColor="#FFFFFF" >
</Button>
</TableRow>

</TableLayout>

</LinearLayout>

实现代码:

CalculatorActivity.java

package com.ltl.calculator;

import java.security.PublicKey;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class CalculatorActivity extends Activity {
/** Called when the activity is first created. */
private String str = "";
private EditText et_show;// 显示屏
private int sign = 0, flag = 0;// sign符号 ,flag暂存
private double num1 = 0.0, num2 = 0.0, result = 0.0;
private View vi;//控件

// 计算方法
public double calculater() {
switch (sign) {
case 0:
result = num2;
break; // 等于
case 1:
result = num1 + num2;
break;// 加
case 2:
result = num1 - num2;
break;// 减
case 3:
result = num1 * num2;
break;// 乘
case 4:
result = num1 / num2;
break;// 除

}
num1 = result;
sign = 0;
return result;
}

// 窗体内容
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_calculator);
// 获得按键
final Button number[]=new Button[10];//数字
final Button mark[]=new Button[11];//符号
mark[0] = (Button) findViewById(R.id.btnAdd);// 加
mark[1] = (Button) findViewById(R.id.btnMinus);// 减
mark[2] = (Button) findViewById(R.id.btnMultiply);// 乘
mark[3] = (Button) findViewById(R.id.btnDivide);// 除
mark[4] = (Button) findViewById(R.id.btnEqual);// 等于
mark[5] = (Button) findViewById(R.id.btnPoint);// 小数点
mark[6] = (Button) findViewById(R.id.btnClears);// 清屏
mark[7] = (Button) findViewById(R.id.btnClearAll);// 全清
mark[8] = (Button) findViewById(R.id.btnPlusOrMinus);// 正负
mark[9] = (Button) findViewById(R.id.btnRadicals);// 开根号
mark[10] = (Button) findViewById(R.id.btnSquare);// 平方

number[0] = (Button) findViewById(R.id.btnZero);// 0
number[1] = (Button) findViewById(R.id.btnOne);// 1
number[2] = (Button) findViewById(R.id.btnTwo);// 2
number[3] = (Button) findViewById(R.id.btnThree);// 3
number[4] = (Button) findViewById(R.id.btnFour);// 4
number[5] = (Button) findViewById(R.id.btnFive);// 5
number[6] = (Button) findViewById(R.id.btnSix);// 6
number[7] = (Button) findViewById(R.id.btnSeven);// 7
number[8] = (Button) findViewById(R.id.btnEight);// 8
number[9] = (Button) findViewById(R.id.btnNine);// 9

et_show = (EditText) findViewById(R.id.et_show);// 显示框
et_show.setKeyListener(null);// 设置文本为只读
et_show.setText(str);// 赋值

// 设定数字按键0
number[0].setOnClickListener(new View.OnClickListener() {

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

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

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 2;
et_show.setText(str);
flag = 0;
} else {
str += 2;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键3
number[3].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 3;
et_show.setText(str);
flag = 0;
} else {
str += 3;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键4
number[4].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 4;
et_show.setText(str);
flag = 0;
} else {
str += 4;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键5
number[5].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 5;
et_show.setText(str);
flag = 0;
} else {
str += 5;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键6
number[6].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 6;
et_show.setText(str);
flag = 0;
} else {
str += 6;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键7
number[7].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 7;
et_show.setText(str);
flag = 0;
} else {
str += 7;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键8
number[8].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 8;
et_show.setText(str);
flag = 0;
} else {
str += 8;
et_show.setText(str);
}
vi = v;

}
});
// 设定数字按键9
number[9].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (flag == 1) {
str = "";
str += 9;
et_show.setText(str);
flag = 0;
} else {
str += 9;
et_show.setText(str);
}
vi = v;

}
});
// 设定符号键
//加
mark[0].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
if(vi==mark[0]||vi==mark[1]||vi==mark[2]||vi==mark[3]){
sign=1;
}else{
num2=Double.parseDouble(str);
calculater();
str=""+result;
et_show.setText(str);
sign=1;
flag=1;
vi=v;
}}
}
});
//减
mark[1].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
if(vi==mark[0]||vi==mark[1]||vi==mark[2]||vi==mark[3]){
sign=2;
}else{
num2=Double.parseDouble(str);
calculater();
str=""+result;
et_show.setText(str);
sign=2;
flag=1;
vi=v;
}}
}
});
//乘
mark[2].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
if(vi==mark[0]||vi==mark[1]||vi==mark[2]||vi==mark[3]){
sign=3;
}else{
num2=Double.parseDouble(str);
calculater();
str=""+result;
et_show.setText(str);
sign=3;
flag=1;
vi=v;
}}
}
});
//除
mark[3].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
if(vi==mark[0]||vi==mark[1]||vi==mark[2]||vi==mark[3]){
sign=4;
}else{
num2=Double.parseDouble(str);
calculater();
str=""+result;
et_show.setText(str);
sign=4;
flag=1;
vi=v;
}}

}
});
//等号
mark[4].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""&&vi!=mark[0]&&vi!=mark[1]&&vi!=mark[2]&&vi!=mark[3]){
num2=Double.parseDouble(str);
calculater();
str=""+result;
et_show.setText(str);
flag=1;
vi=v;

}

}
});
mark[5].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (str == "") {
str += ".";
et_show.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_show.setText(str);
}
}
}
});
//清屏
mark[6].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
str="";
et_show.setText(str);
vi=v;

}
});
//全清
mark[7].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
num1=0.0;num2=0;result=0.0;
str="";
et_show.setText(str);

}
});
//正负
mark[8].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(vi!=mark[5]&&str!=""){
char ch=str.charAt(0);
if(ch=='-')
str=str.replace("-","");
else
str="-"+str;
et_show.setText(str);
}

}
});
//开方
mark[9].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
double a=Double.parseDouble(str);
str=Math.sqrt(a)+"";
et_show.setText(str);
}}

});
//平方
mark[10].setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(str!=""){
double a=Double.parseDouble(str);
str=""+a*a;
et_show.setText(str);
}

}
});
}

// 菜单选项
public boolean onCreateOptionsMenu(Menu menu){
MenuInflater inflater=new MenuInflater(this);
inflater.inflate(R.menu.menu_calculator, menu);
menu.add(0,1,1,"exit");
return super.onCreateOptionsMenu(menu);

}

// 菜单事件
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == 1) {
finish();
}
return super.onOptionsItemSelected(item);
}
}