android studio 简易计算器制作

Posted 2023-04-15 bertin

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只是记录一下代码，随意取用

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    android:orientation="vertical"
    tools:context=".MainActivity">
    <LinearLayout
    android:layout_
    android:layout_
    android:orientation="horizontal">
    </LinearLayout>
<!--写一个计算器的layout-->
    <TextView
        android:id="@+id/tv_result"
        android:layout_
        android:layout_
        android:layout_margin="10dp"
        android:background="@color/white"
        android:gravity="right"
        android:padding="10dp"
        android:text=" "
        android:textColor="@color/black"
        android:textSize="30sp"
        tools:ignore="DuplicateIds" />

    <LinearLayout
        android:layout_
        android:layout_
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_clear"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="C"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_del"
            android:layout_
            android:layout_
            android:layout_margin="6dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="Del"
            android:textColor="@color/white"
            android:textSize="20sp" />

        <Button
            android:id="@+id/btn_div"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="/"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_mul"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="*"
            android:textColor="@color/white"
            android:textSize="30sp" />
    </LinearLayout>

<!--计算器的数字按键-->
    <LinearLayout
        android:layout_
        android:layout_
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_7"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="7"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_8"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="8"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_9"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="9"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_sub"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="-"
            android:textColor="@color/white"
            android:textSize="30sp" />
    </LinearLayout>

    <LinearLayout
        android:layout_
        android:layout_
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_4"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="4"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_5"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="5"
            android:textColor="@color/white"
            android:textSize="30sp" />
        <Button
            android:id="@+id/btn_6"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="6"
            android:textColor="@color/white"
            android:textSize="30sp" />
<!--        补充符号-->
        <Button
            android:id="@+id/btn_add"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="+"
            android:textColor="@color/white"
            android:textSize="30sp" />
    </LinearLayout>

    <LinearLayout
        android:layout_
        android:layout_
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_1"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="1"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_2"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="2"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_3"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="3"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_equal"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="="
            android:textColor="@color/white"
            android:textSize="30sp" />
    </LinearLayout>
<!--    百分号，0，小数点按键-->
    <LinearLayout
        android:layout_
        android:layout_
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_percent"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="%"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_0"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="0"
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_point"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="."
            android:textColor="@color/white"
            android:textSize="30sp" />

        <Button
            android:id="@+id/btn_none"
            android:layout_
            android:layout_
            android:layout_margin="10dp"
            android:layout_weight="1"
            android:background="@color/white"
            android:text="B"
            android:textColor="@color/white"
            android:textSize="30sp" />
    </LinearLayout>

</LinearLayout>

然后是MainActivity.java

package com.zdb.hwfrist;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.os.Bundle;
//导入数据框
import android.widget.Button;
import android.widget.TextView;

import java.util.Stack;


public class MainActivity extends AppCompatActivity 
    //创建button对象
    Button btn_none,btn_0, btn_1, btn_2, btn_3, btn_4, btn_5, btn_6, btn_7, btn_8, btn_9, btn_percent, btn_del, btn_point, btn_add, btn_sub, btn_mul, btn_div, btn_equal, btn_clear;
    //创建TextView对象
    TextView tv_result;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        实例化对象
        btn_0 = findViewById(R.id.btn_0);
        btn_1 = findViewById(R.id.btn_1);
        btn_2 = findViewById(R.id.btn_2);
        btn_3 = findViewById(R.id.btn_3);
        btn_4 = findViewById(R.id.btn_4);
        btn_5 = findViewById(R.id.btn_5);
        btn_6 = findViewById(R.id.btn_6);
        btn_7 = findViewById(R.id.btn_7);
        btn_8 = findViewById(R.id.btn_8);
        btn_9 = findViewById(R.id.btn_9);
        btn_percent = findViewById(R.id.btn_percent);
        btn_add = findViewById(R.id.btn_add);
        btn_sub = findViewById(R.id.btn_sub);
        btn_mul = findViewById(R.id.btn_mul);
        btn_div = findViewById(R.id.btn_div);
        btn_del = findViewById(R.id.btn_del);
        btn_equal = findViewById(R.id.btn_equal);
        btn_point = findViewById(R.id.btn_point);
        btn_clear = findViewById(R.id.btn_clear);
        tv_result = findViewById(R.id.tv_result);
        btn_none = findViewById(R.id.btn_none);
//        给按钮添加点击事件

        btn_0.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "0");
        );
        btn_1.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "1");
        );
        btn_2.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "2");
        );
        btn_3.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "3");
        );
        btn_4.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "4");
        );
        btn_5.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "5");
        );
        btn_6.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "6");
        );
        btn_7.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "7");
        );
        btn_8.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "8");
        );
        btn_9.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "9");
        );
        btn_point.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + ".");
        );
        btn_clear.setOnClickListener(v -> 
            tv_result.setText(" ");
        );
        btn_none.setOnClickListener(v -> 
            tv_result.setText("叫你手贱，点我干什么");
        );
        btn_del.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            if (str_out.length() == 1) 
                tv_result.setText(" ");
             else 
                tv_result.setText(str_out.substring(0, str_out.length() - 1));
            
        );
        btn_add.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "+");
        );
        btn_sub.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "-");
        );
        btn_mul.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "*");
        );
        btn_div.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "/");
        );
        btn_percent.setOnClickListener(v -> 
            String str_out = tv_result.getText().toString();
            tv_result.setText(str_out + "%");
        );

        btn_equal.setOnClickListener(v -> 
            String str = tv_result.getText().toString();
//            如果str是中文，就不执行
            if (str.contains("叫")) 
                return;
            
//            如果str是空的，就不执行
            if (str.equals(" ")) 
                return;
            
//            如果str是以运算符结尾，就不执行
            if (str.endsWith("+") || str.endsWith("-") || str.endsWith("*") || str.endsWith("/")) 
                tv_result.setText(str+"好好写");
                return;
            
            str="1*"+str;
//            如果str有%，则在%后面加一个1
            if (str.contains("%")) 
                str = str.replace("%", "%0");
            
            Object result = calculate(str);
            System.out.println(result);

//                打印result
            System.out.println(result);
//               如果小数点后面是0，就不显示
            if (result.toString().endsWith(".0")) 
                tv_result.setText(result.toString().substring(0, result.toString().length() - 2));
             else 
                tv_result.setText(result + "");
            


        );
    

    public static double calculate(String input) 
        String[] parts = input.split("(?<=[-+*/%])|(?=[-+*/%])");
        Stack<Double> numbers = new Stack<>();
        Stack<Character> operators = new Stack<>();
        for (String part : parts) 
            part = part.trim();
            if (part.isEmpty()) 
                continue;
            
            char firstChar = part.charAt(0);
            if (Character.isDigit(firstChar)) 
                double num = Double.parseDouble(part);
                numbers.push(num);
             else 
                while (!operators.isEmpty() && shouldPopOperator(operators.peek(), firstChar)) 
                    char op = operators.pop();
                    double num2 = numbers.pop();
                    double num1 = numbers.pop();
                    double result = calculateOneOperation(num1, num2, op);
                    numbers.push(result);
                
                operators.push(firstChar);
            
        
        while (!operators.isEmpty()) 
            char op = operators.pop();
            double num2 = numbers.pop();
            double num1 = numbers.pop();
            double result = calculateOneOperation(num1, num2, op);
            numbers.push(result);
        
        return numbers.pop();
    

    private static boolean shouldPopOperator(char op1, char op2) 
        if (op1 == \'(\' || op1 == \')\') 
            return false;
        
        int precedence1 = getOperatorPrecedence(op1);
        int precedence2 = getOperatorPrecedence(op2);
        return precedence1 >= precedence2;
    

    private static int getOperatorPrecedence(char op) 
        switch (op) 
            case \'+\':
            case \'-\':
                return 1;
            case \'*\':
            case \'/\':
                return 2;
            case \'%\':
                return 3;
            default:
                return 0;
        
    

    private static double calculateOneOperation(double num1, double num2, char op) 
        switch (op) 
            case \'%\':
                return num1 * 0.01;
            case \'+\':
                return num1 + num2;
            case \'-\':
                return num1 - num2;
            case \'*\':
                return num1 * num2;
            case \'/\':
                return num1 / num2;

            default:
                throw new IllegalArgumentException("Invalid operator: " + op);

制作一个简易计算器——基于Android Studio实现

一个计算器Android程序的源码部分分为主干和细节两部分。

一、主干

1. 主干的构成

计算器的布局
事件（即计算器上的按钮、文本框）监听
实现计算

2. 详细解释

　　假设我们的项目名为Calculator，而布局名称（Layout Name）为默认的activity_main 。即设置如下图所示：

　　在这种前提下，有：

设置计算器布局的文件：Calculator/app/src/main/res/layout/activity_main.xml
事件监听和计算实现在同一个文件里：Calculator/app/src/main/java/下的一个子目录里的MainActivity.java

　　即如下图所示：

3. 主干代码部分

计算器布局代码（写在activity_main.xml文件里）：

  1 <?xml version="1.0" encoding="utf-8"?>
  2 <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  3     android:layout_width="fill_parent"
  4     android:layout_height="wrap_content"
  5     >
  6     <LinearLayout
  7         android:layout_width="fill_parent"
  8         android:layout_height="fill_parent"
  9         android:orientation="vertical" >
 10         <EditText
 11             android:id="@+id/input"
 12             android:layout_width="fill_parent"
 13             android:layout_height="wrap_content"
 14             android:layout_gravity="center"
 15             android:editable="false"
 16             android:hint="@string/shuru" />
 17 
 18         <EditText
 19             android:id="@+id/output"
 20             android:layout_width="fill_parent"
 21             android:layout_height="wrap_content"
 22             android:layout_gravity="center"
 23             android:editable="true"
 24             android:gravity="right"
 25             android:hint="@string/shuchu" />
 26 
 27         <RelativeLayout
 28             android:layout_width="fill_parent"
 29             android:layout_height="wrap_content" >
 30 
 31             <Button
 32                 android:id="@+id/seven"
 33                 android:layout_width="80dp"
 34                 android:layout_height="70dp"
 35                 android:layout_alignParentLeft="true"
 36                 android:text="@string/seven"
 37                 android:textSize="40sp" />
 38 
 39             <Button
 40                 android:id="@+id/eight"
 41                 android:layout_width="80dp"
 42                 android:layout_height="70dp"
 43                 android:layout_toRightOf="@id/seven"
 44                 android:text="@string/eight"
 45                 android:textSize="40sp" />
 46 
 47             <Button
 48                 android:id="@+id/nine"
 49                 android:layout_width="80dp"
 50                 android:layout_height="70dp"
 51                 android:layout_toRightOf="@id/eight"
 52                 android:text="@string/nine"
 53                 android:textSize="40sp" />
 54 
 55             <Button
 56                 android:id="@+id/add"
 57                 android:layout_width="80dp"
 58                 android:layout_height="70dp"
 59                 android:layout_alignParentRight="true"
 60                 android:layout_toRightOf="@id/nine"
 61                 android:text="@string/add"
 62                 android:textSize="40sp" />
 63 
 64             <Button
 65                 android:id="@+id/four"
 66                 android:layout_width="80dp"
 67                 android:layout_height="70dp"
 68                 android:layout_alignParentLeft="true"
 69                 android:layout_below="@id/seven"
 70                 android:text="@string/four"
 71                 android:textSize="40sp" />
 72 
 73             <Button
 74                 android:id="@+id/five"
 75                 android:layout_width="80dp"
 76                 android:layout_height="70dp"
 77                 android:layout_below="@id/eight"
 78                 android:layout_toRightOf="@id/four"
 79                 android:text="@string/five"
 80                 android:textSize="40sp" />
 81 
 82             <Button
 83                 android:id="@+id/six"
 84                 android:layout_width="80dp"
 85                 android:layout_height="70dp"
 86                 android:layout_below="@id/nine"
 87                 android:layout_toRightOf="@id/five"
 88                 android:text="@string/six"
 89                 android:textSize="40sp" />
 90 
 91             <Button
 92                 android:id="@+id/subtract"
 93                 android:layout_width="80dp"
 94                 android:layout_height="70dp"
 95                 android:layout_alignParentRight="true"
 96                 android:layout_below="@id/add"
 97                 android:layout_toRightOf="@id/six"
 98                 android:text="@string/subtract"
 99                 android:textSize="40sp" />
100 
101             <Button
102                 android:id="@+id/one"
103                 android:layout_width="80dp"
104                 android:layout_height="70dp"
105                 android:layout_alignParentLeft="true"
106                 android:layout_below="@id/four"
107                 android:text="@string/one"
108                 android:textSize="40sp" />
109 
110             <Button
111                 android:id="@+id/two"
112                 android:layout_width="80dp"
113                 android:layout_height="70dp"
114                 android:layout_below="@id/five"
115                 android:layout_toRightOf="@id/one"
116                 android:text="@string/two"
117                 android:textSize="40sp" />
118 
119             <Button
120                 android:id="@+id/three"
121                 android:layout_width="80dp"
122                 android:layout_height="70dp"
123                 android:layout_below="@id/six"
124                 android:layout_toRightOf="@id/two"
125                 android:text="@string/three"
126                 android:textSize="40sp" />
127 
128             <Button
129                 android:id="@+id/multiply"
130                 android:layout_width="80dp"
131                 android:layout_height="70dp"
132                 android:layout_alignParentRight="true"
133                 android:layout_below="@id/subtract"
134                 android:layout_toRightOf="@id/three"
135                 android:text="@string/multiply"
136                 android:textSize="40sp" />
137 
138             <Button
139                 android:id="@+id/zero"
140                 android:layout_width="80dp"
141                 android:layout_height="70dp"
142                 android:layout_alignParentLeft="true"
143                 android:layout_below="@id/one"
144                 android:text="@string/zero"
145                 android:textSize="40sp" />
146 
147             <Button
148                 android:id="@+id/clear"
149                 android:layout_width="80dp"
150                 android:layout_height="70dp"
151                 android:layout_below="@id/two"
152                 android:layout_toRightOf="@id/zero"
153                 android:text="@string/clear"
154                 android:textSize="40sp" />
155 
156             <Button
157                 android:id="@+id/result"
158                 android:layout_width="80dp"
159                 android:layout_height="70dp"
160                 android:layout_below="@id/three"
161                 android:layout_toRightOf="@id/clear"
162                 android:text="@string/result"
163                 android:textSize="40sp" />
164 
165             <Button
166                 android:id="@+id/divide"
167                 android:layout_width="80dp"
168                 android:layout_height="70dp"
169                 android:layout_alignParentRight="true"
170                 android:layout_below="@id/multiply"
171                 android:layout_toRightOf="@id/result"
172                 android:text="@string/divide"
173                 android:textSize="40sp" />
174 
175             <Button
176                 android:id="@+id/dot"
177                 android:layout_width="80dp"
178                 android:layout_height="70dp"
179                 android:layout_alignParentLeft="true"
180                 android:layout_below="@id/zero"
181                 android:text="@string/dot"
182                 android:textSize="40sp" />
183             <Button
184                 android:id="@+id/writeButton"
185                 android:layout_width="wrap_content"
186                 android:layout_height="wrap_content"
187                 android:layout_alignParentLeft="true"
188                 android:layout_below="@id/dot"
189                 android:text="@string/write"
190                 android:textSize="40sp" />
191             <Button
192                 android:id="@+id/readButton"
193                 android:layout_width="wrap_content"
194                 android:layout_height="wrap_content"
195                 android:layout_alignParentRight="true"
196                 android:layout_below="@id/dot"
197                 android:text="@string/read"
198                 android:textSize="40sp" />
199 
200             <CheckBox
201                 android:id="@+id/appendBox"
202                 android:text="@string/appendBox"
203                 android:layout_width="wrap_content"
204                 android:layout_height="wrap_content"
205                 android:layout_alignParentBottom="true"
206                 android:layout_toLeftOf="@+id/divide"
207                 android:layout_toStartOf="@+id/divide"
208                 android:layout_marginBottom="12dp"
209                 />
210 
211         </RelativeLayout>
212 
213         <EditText
214 
215             android:layout_width="match_parent"
216             android:layout_height="wrap_content"
217             android:id="@+id/textView" />
218 
219         <EditText
220 
221             android:layout_width="match_parent"
222             android:layout_height="wrap_content"
223             android:id="@+id/displayView" />
224 
225         <EditText
226             android:id="@+id/errorzero"
227             android:layout_width="fill_parent"
228             android:layout_height="wrap_content"
229             android:layout_gravity="center"
230             android:editable="false"
231             android:gravity="center"
232             />
233         <EditText
234             android:id="@+id/resultText"
235             android:layout_width="fill_parent"
236             android:layout_height="wrap_content"
237             android:layout_gravity="center"
238             android:editable="false"
239             android:gravity="left"
240             android:text="@string/resultText"
241             />
242     </LinearLayout>
243 </ScrollView>

View Code

事件监听和实现计算代码（写在MainActivity.java文件里）

  1 package com.example.lenovo.calculator;
  2 
  3 
  4 
  5         import android.app.Activity;
  6         import android.content.Context;
  7         import android.os.Bundle;
  8         import android.view.View;
  9         import android.view.View.OnClickListener;
 10         import android.widget.Button;
 11         import android.widget.CheckBox;
 12         import android.widget.EditText;
 13 
 14         import java.io.FileInputStream;
 15         import java.io.FileNotFoundException;
 16         import java.io.FileOutputStream;
 17         import java.io.IOException;
 18 
 19 public class MainActivity extends Activity {
 20     /**
 21      * Called when the activity is first created.
 22      */
 23     private EditText output = null;
 24     private EditText input = null;
 25     private Button btn0 = null;
 26     private Button btn1 = null;
 27     private Button btn2 = null;
 28     private Button btn3 = null;
 29     private Button btn4 = null;
 30     private Button btn5 = null;
 31     private Button btn6 = null;
 32     private Button btn7 = null;
 33     private Button btn8 = null;
 34     private Button btn9 = null;
 35     private Button btnadd = null;
 36     private Button btnsubtract = null;
 37     private Button btnmultiply = null;
 38     private Button btndivide = null;
 39     private Button btnclear = null;
 40     private Button btnresult = null;
 41     private Button btndot = null;
 42 
 43     private EditText errorzero = null;
 44 
 45     private EditText resultText = null;
 46     private Button writeButton = null;
 47     private Button readButton = null;
 48     private CheckBox appendBox = null;
 49     private EditText textView = null;
 50     private EditText displayView = null;
 51     public String FILE_NAME = "fileDemo.txt";
 52 
 53 
 54     private String str = "";//保存数字
 55     private String strold = "";//原数字
 56     private char act = \' \';//记录“加减乘除等于”符号
 57     private int count = 0;//判断要计算的次数，如果超过一个符号，先算出来一部分
 58     private Float result = null;//计算的输出结果
 59     private Boolean errBoolean = false;//有错误的时候为true，无错为false
 60     private Boolean flagBoolean = false;//一个标志，如果为true，可以响应运算消息，如果为false，不响应运算消息，只有前面是数字才可以响应运算消息
 61     private Boolean flagDot = false; //小数点标志位
 62 
 63 
 64 
 65     @Override
 66     public void onCreate(Bundle savedInstanceState) {
 67         super.onCreate(savedInstanceState);
 68         setContentView(R.layout.activity_main);
 69 
 70         output = (EditText) findViewById(R.id.output);
 71         input = (EditText) findViewById(R.id.input);
 72 
 73         errorzero = (EditText) findViewById(R.id.errorzero);
 74         resultText = (EditText) findViewById(R.id.resultText);
 75         writeButton = (Button) findViewById(R.id.writeButton);
 76         readButton = (Button) findViewById(R.id.readButton);
 77         textView = (EditText) findViewById(R.id.textView);
 78         displayView = (EditText) findViewById(R.id.displayView);
 79         appendBox = (CheckBox) findViewById(R.id.appendBox);
 80 
 81         btn0 = (Button) findViewById(R.id.zero);
 82         btn1 = (Button) findViewById(R.id.one);
 83         btn2 = (Button) findViewById(R.id.two);
 84         btn3 = (Button) findViewById(R.id.three);
 85         btn4 = (Button) findViewById(R.id.four);
 86         btn5 = (Button) findViewById(R.id.five);
 87         btn6 = (Button) findViewById(R.id.six);
 88         btn7 = (Button) findViewById(R.id.seven);
 89         btn8 = (Button) findViewById(R.id.eight);
 90         btn9 = (Button) findViewById(R.id.nine);
 91         btnadd = (Button) findViewById(R.id.add);
 92         btnsubtract = (Button) findViewById(R.id.subtract);
 93         btnmultiply = (Button) findViewById(R.id.multiply);
 94         btndivide = (Button) findViewById(R.id.divide);
 95         btnclear = (Button) findViewById(R.id.clear);
 96         btnresult = (Button) findViewById(R.id.result);
 97         btndot = (Button) findViewById(R.id.dot);
 98         //设置按钮侦听事件
 99         btn0.setOnClickListener(listener);
100         btn1.setOnClickListener(listener);
101         btn2.setOnClickListener(listener);
102         btn3.setOnClickListener(listener);
103         btn4.setOnClickListener(listener);
104         btn5.setOnClickListener(listener);
105         btn6.setOnClickListener(listener);
106         btn7.setOnClickListener(listener);
107         btn8.setOnClickListener(listen以上是关于android studio 简易计算器制作的主要内容，如果未能解决你的问题，请参考以下文章 
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