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Androidstudio實(shí)現(xiàn)簡單的計算器
本文實(shí)例為大家分享了Android studio實(shí)現(xiàn)簡單計算器的具體代碼，供大家參考，具體內(nèi)容如下
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需求分析及概要設(shè)計
目的
開發(fā)一個簡單的計算器App,使之能夠完成加減乘除混合運(yùn)算
工具及環(huán)境
使用java語言，在Android studio平臺上進(jìn)行開發(fā)
功能設(shè)計
- “+”:實(shí)現(xiàn)兩數(shù)相加
- “-”:實(shí)現(xiàn)兩數(shù)相減
- “*”:實(shí)現(xiàn)兩數(shù)相乘
- “/”:實(shí)現(xiàn)兩數(shù)相除
- “=”:計算并得出正確結(jié)果
- “C”:清屏
- “Backspace”:倒退
設(shè)計思路
1、首先設(shè)計一個可視化的界面，供用戶輸入數(shù)據(jù)并查看結(jié)果。
2、用戶可通過點(diǎn)擊相應(yīng)按鈕輸入正確的表達(dá)式（注意：這里只實(shí)現(xiàn)對正確表達(dá)式的計算處理），最后按"="得出正確結(jié)果。在計算過程中可以通過點(diǎn)擊倒退鍵修改輸入內(nèi)容，在進(jìn)行下一次的運(yùn)算之前必須先進(jìn)行清零操作。
3、設(shè)計好的計算器應(yīng)可以進(jìn)行加減乘除混合四則運(yùn)算，且可以進(jìn)行小數(shù)和整數(shù)運(yùn)算
詳細(xì)設(shè)計
當(dāng)用戶點(diǎn)擊按鈕時，用SringBuilder變量記錄其輸入的運(yùn)算式，并顯示到文本區(qū)中。
當(dāng)用戶點(diǎn)擊"="時，把文本區(qū)的運(yùn)算式拿出來，首先將它內(nèi)部的一個一個字節(jié)拼接成獨(dú)立的運(yùn)算數(shù)和運(yùn)算符，然后存儲在一個ArrayList數(shù)組中，接著再新建兩個ArrayList數(shù)組，用來分別存放運(yùn)算數(shù)和運(yùn)算符，然后遍歷存儲運(yùn)算式的ArrayList數(shù)組，把其中的運(yùn)算數(shù)和運(yùn)算符分別放進(jìn)不同的ArrayList中，每一次放置運(yùn)算符時，都要先和已存在的運(yùn)算符進(jìn)行比較，若要放進(jìn)的運(yùn)算符優(yōu)先級低于或等于運(yùn)算符數(shù)組中的運(yùn)算符，則彈出一個運(yùn)算符，并從運(yùn)算數(shù)數(shù)組中彈出兩個運(yùn)算數(shù)，然后進(jìn)行運(yùn)算，并把結(jié)果送入運(yùn)算數(shù)數(shù)組中，直到遇到比自己優(yōu)先級低的運(yùn)算符或運(yùn)算符數(shù)組為空時，則送入該運(yùn)算符。當(dāng)遍歷到運(yùn)算式末尾時，依次彈出運(yùn)算符中的運(yùn)算符，并對應(yīng)彈出運(yùn)算數(shù)進(jìn)行運(yùn)算直到運(yùn)算符數(shù)組為空，此時運(yùn)算數(shù)數(shù)組中只有一個數(shù)據(jù)就是最終的結(jié)果
代碼
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();//顯示運(yùn)算式
private ArrayList calculate_equation;//計算式
private int signal=0;//為0 時表示剛輸入狀態(tài)；為1 時表示當(dāng)前在輸出結(jié)果上繼續(xù)輸入
@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);
//點(diǎn)擊文本框時光標(biāo)始終在文本末尾
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) {
//判斷用戶是否輸入了內(nèi)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='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");
//跳過2個字符
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) {
//判斷用戶是否輸入了內(nèi)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) {
//判斷用戶是否輸入了內(nèi)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) {
//判斷用戶是否輸入了內(nèi)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) {
//判斷用戶是否輸入了內(nèi)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();
}
//相減
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 operand=new ArrayList();
for(int i=0;i0)
{
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();
}
//當(dāng)API最低版小于21時使用這個函數(shù)實(shí)現(xiàn)點(diǎn)擊文本框不彈出鍵盤
public void disableShowInput(EditText et) {
Class 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"?>
buttonstytle.xml
<?xml version="1.0" encoding="utf-8"?>
####結(jié)果分析
啟動計算器并輸入運(yùn)算式“59.0-8/46+2”如下圖：
結(jié)果如下圖：
總結(jié)
這次做計算器收獲很大，首先我對Android studio中的布局有了更深刻的認(rèn)識，其次在這次編程中熟悉了怎么設(shè)置斷點(diǎn)調(diào)試以快速的找出問題所在。當(dāng)然，這次的作品也是不夠成熟的，因?yàn)闆]有做有關(guān)錯誤表達(dá)式的相應(yīng)處理，因?yàn)闀r間和精力有限，這次只能先做這么多了
注： 今天沒事又看了一下這個代碼，發(fā)現(xiàn)問題很多，簡直是慘不忍睹（希望沒坑到你們）。比如直接按加、減、乘、除和等號鍵及后退鍵會閃退，剛開始一直按 “0” 可以一直輸入0，同一個數(shù)中可以輸入多個小數(shù)點(diǎn)等等，我感到很慚愧哈，本人能力有限，不過還是抽時間又改了一下，修復(fù)了這些bug，另外也優(yōu)化了一些東西，上面貼的代碼我已經(jīng)更新了，GitHub上的源碼我很快也會更新的，哪里做的不好也希望大家不吝賜教哈 -2018/11/5
鏈接：源代碼下載地址
更多計算器功能實(shí)現(xiàn)，請點(diǎn)擊專題： 計算器功能匯總 進(jìn)行學(xué)習(xí)
關(guān)于Android計算器功能的實(shí)現(xiàn)，查看專題：Android計算器 進(jìn)行學(xué)習(xí)。
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網(wǎng)站標(biāo)題：Androidstudio實(shí)現(xiàn)簡單的計算器
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