Android studio实现简单的计算器

作者:一颗暗色星辰 时间:2022-09-07 23:23:28 

本文实例为大家分享了Android studio实现简单计算器的具体代码,供大家参考,具体内容如下

需求分析及概要设计

目的

开发一个简单的计算器App,使之能够完成加减乘除混合运算

工具及环境

使用java语言,在Android studio平台上进行开发

功能设计

  • “+”:实现两数相加

  • “-”:实现两数相减

  • “*”:实现两数相乘

  • “/”:实现两数相除

  • “=”:计算并得出正确结果

  • “C”:清屏

  • “Backspace”:倒退

设计思路

1、首先设计一个可视化的界面,供用户输入数据并查看结果。
2、用户可通过点击相应按钮输入正确的表达式(注意:这里只实现对正确表达式的计算处理),最后按"="得出正确结果。在计算过程中可以通过点击倒退键修改输入内容,在进行下一次的运算之前必须先进行清零操作。
3、设计好的计算器应可以进行加减乘除混合四则运算,且可以进行小数和整数运算

详细设计

当用户点击按钮时,用SringBuilder变量记录其输入的运算式,并显示到文本区中。

当用户点击"="时,把文本区的运算式拿出来,首先将它内部的一个一个字节拼接成独立的运算数和运算符,然后存储在一个ArrayList数组中,接着再新建两个ArrayList数组,用来分别存放运算数和运算符,然后遍历存储运算式的ArrayList数组,把其中的运算数和运算符分别放进不同的ArrayList中,每一次放置运算符时,都要先和已存在的运算符进行比较,若要放进的运算符优先级低于或等于运算符数组中的运算符,则弹出一个运算符,并从运算数数组中弹出两个运算数,然后进行运算,并把结果送入运算数数组中,直到遇到比自己优先级低的运算符或运算符数组为空时,则送入该运算符。当遍历到运算式末尾时,依次弹出运算符中的运算符,并对应弹出运算数进行运算直到运算符数组为空,此时运算数数组中只有一个数据就是最终的结果

代码

MainAcivity.java


package com.example.qw.calculator;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity{

private StringBuilder show_equation=new StringBuilder();//显示运算式
private ArrayList calculate_equation;//计算式
private int signal=0;//为0 时表示刚输入状态;为1 时表示当前在输出结果上继续输入
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化
show_equation=new StringBuilder();
calculate_equation=new ArrayList<>();
Button zero=(Button)findViewById(R.id.zero);
Button one=(Button)findViewById(R.id.one);
Button two=(Button)findViewById(R.id.two);
Button three=(Button)findViewById(R.id.three);
Button four=(Button)findViewById(R.id.four);
Button five=(Button)findViewById(R.id.five);
Button six=(Button)findViewById(R.id.six);
Button seven=(Button)findViewById(R.id.seven);
Button eight=(Button)findViewById(R.id.eight);
Button nine=(Button)findViewById(R.id.nine);
Button cls=(Button)findViewById(R.id.cls);
Button div=(Button)findViewById(R.id.div);
Button mul=(Button)findViewById(R.id.mul);
Button backspace=(Button)findViewById(R.id.Backspace);
Button sub=(Button)findViewById(R.id.sub);
Button add=(Button)findViewById(R.id.add);
final Button equal=(Button)findViewById(R.id.equal);
final Button point=(Button)findViewById(R.id.spot);
final EditText result=(EditText)findViewById(R.id.result);
result.setCursorVisible(true);
disableShowInput(result);
//点击文本框时光标始终在文本末尾
result.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View view) {
 result.setSelection(result.getText().length());
 }
});
zero.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v){
  if(!(show_equation.toString().equals("0"))){
  if(signal==0){
   show_equation.append("0");
   result.setText(show_equation);
   result.setSelection(result.getText().length());
  }else{
   show_equation.delete(0,show_equation.length());
   show_equation.append("0");
   result.setText(show_equation);
   result.setSelection(result.getText().length());
   signal=0;
  }
  }
 }
});
one.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("1");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("1");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
two.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("2");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("2");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
three.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("3");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("3");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
 four.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("4");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("4");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
five.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("5");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("5");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
six.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("6");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("6");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
seven.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("7");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("7");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
eight.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("8");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("8");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
nine.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  show_equation.append("9");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append("9");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});
cls.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 show_equation.delete(0,show_equation.length());
 calculate_equation.clear();
 signal=0;
 result.setText("");
 }
});
backspace.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(!(show_equation.toString().equals(""))) {
  if(signal==0){
  show_equation.deleteCharAt(show_equation.length() - 1);
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  }else{
  show_equation.delete(0,show_equation.length());
  result.setText("");
  signal=0;
  }
 }
 }
});
point.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 if(signal==0){
  String a=show_equation.toString();
  if(a.equals("")){
  show_equation.append(".");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
  }else{
  int i;
  char t='0';
  for(i=a.length();i>0;i--){
   t=a.charAt(i-1);
   if(t=='.'||t=='+'||t=='-'||t=='*'||t=='/')
   break;
  }
  if(i==0){
   show_equation.append(".");
   result.setText(show_equation);
   result.setSelection(result.getText().length());
  }else if(t=='+'||t=='-'||t=='*'||t=='/'){
   show_equation.append(".");
   result.setText(show_equation);
   result.setSelection(result.getText().length());
  }
  }
 }else{
  show_equation.delete(0,show_equation.length());
  show_equation.append(".");
  result.setText(".");
  result.setSelection(result.getText().length());
  signal=0;
 }
 }
});

equal.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //判断用户是否输入了内容
 if(!show_equation.toString().equals("")){
  signal=1;
  char temp=show_equation.charAt(show_equation.length()-1);
  if(show_equation.charAt(0)=='-')
  show_equation.insert(0,"0");
  if(temp=='+'||temp=='-')
  show_equation.append("0");
  if(temp=='*'||temp=='/')
  show_equation.append("1");
  StringBuilder temp1=new StringBuilder();
  for(int i=0;i<show_equation.length();i++){
  if(show_equation.charAt(i)>='0'&&show_equation.charAt(i)<='9'||show_equation.charAt(i)=='.'){
   temp1.append(String.valueOf(show_equation.charAt(i)));
  }else if(show_equation.charAt(i)=='N'){
   calculate_equation.add("NaN");
   //跳过2个字符
   i=i+2;
  }else if(show_equation.charAt(i)=='∞'){
   calculate_equation.add("∞");
  }
  else
  {
   if(temp1.length()!=0){
   calculate_equation.add(temp1.toString());
   temp1.delete(0,temp1.length());
   }
   calculate_equation.add(String.valueOf(show_equation.charAt(i)));
  }
  }
  if(temp1.length()!=0){
  calculate_equation.add(temp1.toString());
  }
  calculate_equation.add("#");
  String temp8=calculate(calculate_equation);
  result.setText(temp8);
  result.setSelection(result.getText().length());
  show_equation.delete(0,show_equation.length());
  calculate_equation.clear();
  show_equation.append(temp8);
 }
 }
});
add.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //判断用户是否输入了内容
 if(!(show_equation.toString().equals(""))) {
  signal=0;
  char temp=show_equation.charAt(show_equation.length()-1);
  if(temp=='+'||temp=='-'||temp=='*'||temp=='/')
  {
  show_equation.deleteCharAt(show_equation.length()-1);
  show_equation.append("+");
  }
  else
  show_equation.append("+");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }
 }
});
sub.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //判断用户是否输入了内容
 if(!(show_equation.toString().equals(""))) {
  signal=0;
  char temp=show_equation.charAt(show_equation.length()-1);
  if(temp=='+'||temp=='-'||temp=='*'||temp=='/')
  {
  show_equation.deleteCharAt(show_equation.length()-1);
  show_equation.append("-");
  }
  else
  show_equation.append("-");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }
 }
});

mul.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //判断用户是否输入了内容
 if(!(show_equation.toString().equals(""))) {
  signal=0;
  char temp=show_equation.charAt(show_equation.length()-1);
  if(temp=='+'||temp=='-'||temp=='*'||temp=='/')
  {
  show_equation.deleteCharAt(show_equation.length()-1);
  show_equation.append("*");
  }
  else
  show_equation.append("*");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }
 }
});

div.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 //判断用户是否输入了内容
 if(!(show_equation.toString().equals(""))) {
  signal=0;
  char temp=show_equation.charAt(show_equation.length()-1);
  if(temp=='+'||temp=='-'||temp=='*'||temp=='/')
  {
  show_equation.deleteCharAt(show_equation.length()-1);
  show_equation.append("/");
  }
  else
  show_equation.append("/");
  result.setText(show_equation);
  result.setSelection(result.getText().length());
 }
 }
});
}
protected boolean operatorPriorityCompare(char operator1,char operator2)
{
int o1=0;
int o2=0;
switch (operator1){
 case '+':{o1=0;break;}
 case '-':{o1=0;break;}
 case '*':{o1=1;break;}
 case '/':{o1=1;break;}
}
switch (operator2){
 case '+':{o2=0;break;}
 case '-':{o2=0;break;}
 case '*':{o2=1;break;}
 case '/':{o2=1;break;}
}
if(o1<=o2)
{
 return false;
}
else
 return true;
}
//相加
public static Double Add(Double d1,Double d2) {
if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){
 return d1+d2;
}
if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){
 return d1+d2;
}
BigDecimal b1 = new BigDecimal(Double.toString(d1));
BigDecimal b2 = new BigDecimal(Double.toString(d2));
return b1.add(b2).doubleValue();
}
//相减
public static Double Sub(Double d1,Double d2){
if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){
 return d1-d2;
}
if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){
 return d1-d2;
}
if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){
 return d1*d2;
}
BigDecimal b1=new BigDecimal(Double.toString(d1));
BigDecimal b2=new BigDecimal(Double.toString(d2));
return b1.subtract(b2).doubleValue();
}
//相乘
public static Double Mul(Double d1,Double d2){
if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){
 return d1*d2;
}
if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){
 return d1*d2;
}
BigDecimal b1=new BigDecimal(Double.toString(d1));
BigDecimal b2=new BigDecimal(Double.toString(d2));
return b1.multiply(b2).setScale(8).doubleValue();
}
//相除
public static Double Div(Double d1,Double d2){
if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){
 return d1/d2;
}
if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){
 return d1/d2;
}
if(d1==0.0&&d2==0.0){
 return Double.NaN;
}
if(d2==0.0){
 return d1/d2;
}
BigDecimal b1=new BigDecimal(Double.toString(d1));
BigDecimal b2=new BigDecimal(Double.toString(d2));
return b1.divide(b2,8,BigDecimal.ROUND_HALF_UP).doubleValue();
}
protected String calculate(ArrayList equation){
Double temp2;
Double temp3;
Double result;
List operator=new ArrayList();
List<Double> operand=new ArrayList();
for(int i=0;i<equation.size();i++)
{
 String temp4=(String) equation.get(i);
 if(temp4.equals("+")||temp4.equals("-")||temp4.equals("*")||temp4.equals("/"))
 {
 if(operator.size()>0)
 {
  String temp5=operator.get(operator.size()-1).toString();
  while(!(operatorPriorityCompare(temp4.charAt(0),temp5.charAt(0)))&&operator.size()>0)
  {
  operator.remove(operator.size()-1);
  temp3=operand.get(operand.size()-1);
  operand.remove(operand.size()-1);
  temp2=operand.get(operand.size()-1);
  operand.remove(operand.size()-1);
  switch (temp5.charAt(0)){
   case '+':{result=Add(temp2,temp3);operand.add(result);break;}
   case '-':{result=Sub(temp2,temp3);operand.add(result);break;}
   case '*':{result=Mul(temp2,temp3);operand.add(result);break;}
   case '/':{result=Div(temp2,temp3);operand.add(result);break;}
  }
  if(operator.size()>0)
  {
   temp5=operator.get(operator.size()-1).toString();
  }
  else
   break;
  }
  operator.add(temp4);
 }
 else
  operator.add(temp4);
 }
 else if(temp4.equals("#"))
 {
 while(operator.size()>0)
 {
  String temp6=(String)operator.get(operator.size()-1);
  operator.remove(operator.size()-1);
  temp3=operand.get(operand.size()-1);
  operand.remove(operand.size()-1);
  temp2=operand.get(operand.size()-1);
  operand.remove(operand.size()-1);
  switch (temp6.charAt(0)){
  case '+':{result=Add(temp2,temp3);operand.add(result);break;}
  case '-':{result=Sub(temp2,temp3);operand.add(result);break;}
  case '*':{result=Mul(temp2,temp3);operand.add(result);break;}
  case '/':{result=Div(temp2,temp3);operand.add(result);break;}
  }
 }
 }
 else
 {
 if(temp4.equals("NaN")){
  operand.add(Double.NaN);
 }else if(temp4.equals("∞")){
  operand.add(Double.POSITIVE_INFINITY);
 }else{
  operand.add(Double.parseDouble(temp4));
 }
 }
}
if(operand.get(0)==Double.NEGATIVE_INFINITY) return "-∞";
if(operand.get(0)==Double.POSITIVE_INFINITY) return "∞";
return operand.get(0).toString();
}
//当API最低版小于21时使用这个函数实现点击文本框不弹出键盘
public void disableShowInput(EditText et) {
Class<EditText> cls = EditText.class;
Method method;
try {
 method = cls.getMethod("setShowSoftInputOnFocus", boolean.class);
 method.setAccessible(true);
 method.invoke(et, false);
} catch (Exception e) {
 e.printStackTrace();
}
}
}

activity_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="match_parent"
android:layout_height="match_parent">

<EditText
android:id="@+id/result"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="40sp"
android:enabled="false"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal">

<Button
 android:id="@+id/cls"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="C"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/div"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="/"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/mul"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="*"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/Backspace"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="Backspace"
 android:textAllCaps="false"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal">

<Button
 android:id="@+id/seven"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="7"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/eight"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="8"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/nine"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="9"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/sub"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="-"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal">

<Button
 android:id="@+id/four"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="4"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/five"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="5"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/six"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="6"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
<Button
 android:id="@+id/add"
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:textSize="20sp"
 android:text="+"
 android:background="@drawable/buttonstytle"
 android:textColor="#ffffff"/>
</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="2"
android:orientation="horizontal">

<LinearLayout
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:orientation="vertical">

<LinearLayout
 android:layout_width="match_parent"
 android:layout_height="1dp"
 android:layout_weight="1"
 android:orientation="horizontal">
 <Button
  android:id="@+id/one"
  android:layout_width="0dp"
  android:layout_height="match_parent"
  android:layout_weight="1"
  android:textSize="20sp"
  android:text="1"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 <Button
  android:id="@+id/two"
  android:layout_width="0dp"
  android:layout_height="match_parent"
  android:layout_weight="1"
  android:textSize="20sp"
  android:text="2"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 </LinearLayout>
 <LinearLayout
 android:layout_width="match_parent"
 android:layout_height="1dp"
 android:layout_weight="1">
 <Button
  android:id="@+id/zero"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:text="0"
  android:textSize="20sp"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 </LinearLayout>
</LinearLayout>
<LinearLayout
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:orientation="horizontal">
 <LinearLayout
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1"
 android:orientation="vertical">
 <Button
  android:id="@+id/three"
  android:layout_width="match_parent"
  android:layout_height="1dp"
  android:layout_weight="1"
  android:text="3"
  android:textSize="20sp"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 <Button
  android:id="@+id/spot"
  android:layout_width="match_parent"
  android:layout_height="1dp"
  android:layout_weight="1"
  android:text="."
  android:textSize="20sp"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 </LinearLayout>
 <LinearLayout
 android:layout_width="0dp"
 android:layout_height="match_parent"
 android:layout_weight="1">
 <Button
  android:id="@+id/equal"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:text="="
  android:textSize="20sp"
  android:background="@drawable/buttonstytle"
  android:textColor="#ffffff"/>
 </LinearLayout>
</LinearLayout>
</LinearLayout>
</LinearLayout>

buttonstytle.xml


<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
<!-- 主体背景颜色值 -->
<solid android:color="#666666" />
<!-- 连框宽度和颜色值 -->
<stroke
android:width="0.01dp"
android:color="#FFFFFF" />
</shape>

####结果分析

启动计算器并输入运算式“59.0-8/46+2”如下图:

Android studio实现简单的计算器

结果如下图:

Android studio实现简单的计算器

总结

这次做计算器收获很大,首先我对Android studio中的布局有了更深刻的认识,其次在这次编程中熟悉了怎么设置断点调试以快速的找出问题所在。当然,这次的作品也是不够成熟的,因为没有做有关错误表达式的相应处理,因为时间和精力有限,这次只能先做这么多了

注: 今天没事又看了一下这个代码,发现问题很多,简直是惨不忍睹(希望没坑到你们)。比如直接按加、减、乘、除和等号键及后退键会闪退,刚开始一直按 “0” 可以一直输入0,同一个数中可以输入多个小数点等等,我感到很惭愧哈,本人能力有限,不过还是抽时间又改了一下,修复了这些bug,另外也优化了一些东西,上面贴的代码我已经更新了,GitHub上的源码我很快也会更新的,哪里做的不好也希望大家不吝赐教哈 -2018/11/5

链接:源代码下载地址

更多计算器功能实现,请点击专题: 计算器功能汇总 进行学习

关于Android计算器功能的实现,查看专题:Android计算器 进行学习。

来源:https://blog.csdn.net/Chushiniudao/article/details/81743556

标签:Android,studio,计算器
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