android的简单计算器的实现

时间：2022-12-29 14:53:12

终于放假了，不过是没有暑假的暑假了。

好久以前就就有接触过安卓，过了这么久还是没有相当于没有入门状态。昨天有空又做了一个简单的计算器练一下手，如有大神看到请绕行了，因为代码实在写得比较烂。嘿嘿。废话不说了，先上图：

    android的简单计算器的实现      android的简单计算器的实现      android的简单计算器的实现      android的简单计算器的实现

首先看一下这个计算器的结构很简单，包含两各Activity：一个是标准类型（标准Activity），只包含简单的加减乘除，另一个加上了更多的功能（科学Activity），如sin，cos等。

看一下标准Activity的布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textview"
        android:layout_width="337dp"
        android:layout_height="50dp"
        android:gravity="right|bottom"
        android:textSize="30dp" />

        <EditText
            android:id="@+id/edittext1"
            android:layout_width="355dp"
            android:layout_height="70dp" 
            android:inputType="textMultiLine"
    android:gravity="right|bottom"
    android:minLines="2"
    android:textSize="40dp"/>

       <RelativeLayout
           android:layout_width="match_parent"
           android:layout_height="90dp" >

           <Button
               android:id="@+id/qiehuan"
               android:layout_width="100dp"
               android:layout_height="35dp"
               android:layout_alignParentLeft="true"
               android:layout_centerVertical="true"
               android:layout_marginLeft="3dp"
               android:text="标准"
               android:textSize="15dp"
               android:background="@drawable/btneffect" />

       </RelativeLayout>

       <RelativeLayout
           android:layout_width="360dp"
           android:layout_height="80dp" >

           <Button
               android:id="@+id/del"
               android:layout_width="85dp"
               android:layout_height="75dp"
               android:layout_marginLeft="93dp"
               android:background="@drawable/btneffect2"
               android:text="DEL" />

           <Button
               android:id="@+id/cheng"
               android:layout_width="85dp"
               android:layout_height="75dp"
               android:layout_marginLeft="182dp"
               android:background="@drawable/btneffect2"
               android:text="×" />

           <Button
               android:id="@+id/clear"
               android:layout_width="85dp"
               android:layout_height="75dp"
               android:layout_marginLeft="4dp"
               android:background="@drawable/btneffect1"
               android:text="C" />

           <Button
               android:id="@+id/chu"
               android:layout_width="85dp"
               android:layout_height="75dp"
               android:layout_alignParentTop="true"
               android:layout_toRightOf="@+id/cheng"
               android:layout_marginLeft="3dp"
               android:background="@drawable/btneffect2"
               android:text="÷" />

       </RelativeLayout>

        <RelativeLayout
            android:layout_width="360dp"
            android:layout_height="80dp"
            android:orientation="horizontal" >

    <Button
        android:id="@+id/btn7"
        android:layout_width="85dp"
        android:layout_height="75dp"
        android:layout_marginLeft="4dp"
        android:background="@drawable/btneffect"
        android:text="7" />

    <Button
        android:id="@+id/btn9"
        android:layout_width="85dp"
        android:layout_height="75dp"
      android:layout_marginLeft="182dp"
        android:background="@drawable/btneffect"
        android:text="9" />

    <Button
        android:id="@+id/btn8"
        android:layout_width="85dp"
        android:layout_height="75dp"
android:layout_marginLeft="93dp"
        android:background="@drawable/btneffect"
        android:text="8" />

    <Button
        android:id="@+id/jian"
        android:layout_width="85dp"
        android:layout_height="75dp"
android:layout_toRightOf="@+id/btn9"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="3dp"
        android:background="@drawable/btneffect2"
        android:text="-" />

</RelativeLayout>

        <RelativeLayout
            android:layout_width="354dp"
            android:layout_height="80dp"
            android:orientation="horizontal" >

    <Button
    android:id="@+id/btn4"
    android:layout_width="85dp"
    android:layout_height="75dp"
    android:text="4" 
    android:layout_marginLeft="4dp"
    android:background="@drawable/btneffect"/>

    <Button
        android:id="@+id/btn6"
        android:layout_width="85dp"
        android:layout_height="75dp"
android:layout_marginLeft="182dp"
        android:background="@drawable/btneffect"
        android:text="6" />

    <Button
        android:id="@+id/btn5"
        android:layout_width="85dp"
        android:layout_height="75dp"
       android:layout_marginLeft="93dp"
        android:background="@drawable/btneffect"
        android:text="5" />

    <Button
        android:id="@+id/jia"
        android:layout_width="85dp"
        android:layout_height="75dp"
       android:layout_toRightOf="@+id/btn6"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="3dp"
        android:background="@drawable/btneffect2"
        android:text="+" />

</RelativeLayout>

        <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">

    <Button
    android:id="@+id/btn1"
    android:layout_width="85dp"
    android:layout_height="75dp"
    android:text="1"
        android:layout_marginLeft="3dp"
    android:background="@drawable/btneffect" />

    <Button
        android:id="@+id/deng"
        android:layout_width="85dp"
        android:layout_height="155dp"
android:layout_toRightOf="@+id/btn3"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="3dp"
        android:text="=" 
        android:background="@drawable/btneffect1"/>

    <Button
        android:id="@+id/btn3"
        android:layout_width="85dp"
        android:layout_height="75dp"
android:layout_marginLeft="182dp"
        android:text="3"
        android:background="@drawable/btneffect" />

    <Button
        android:id="@+id/btn2"
        android:layout_width="85dp"
        android:layout_height="75dp"
        android:text="2" 
        android:layout_marginLeft="93dp"
        android:background="@drawable/btneffect"/>

<Button
    android:id="@+id/btn0"
    android:layout_width="wrap_content"
    android:layout_height="75dp"
    android:layout_alignParentLeft="true"
    android:layout_alignRight="@+id/btn2"
    android:layout_below="@+id/btn1"
    android:text="0"
        android:layout_marginLeft="3dp"
        android:layout_marginTop="5dp"
    android:background="@drawable/btneffect" />

<Button
    android:id="@+id/dian"
    android:layout_width="85dp"
    android:layout_height="75dp"
    android:layout_alignLeft="@+id/btn3"

    android:layout_alignTop="@+id/btn0"
    android:text="."
    android:background="@drawable/btneffect" />

</RelativeLayout>   
</LinearLayout>

MainActivity.java如下： 

import android.R.string;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.text.InputType;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

private long exitTime = 0;
protected static final float NaN = 0;
private Button[] btnNum = new Button[11];// 数值按钮
private Button clear,del,cheng,chu,jian,jia,deng,qiehuan;
private EditText edittext;
private TextView textview;
int flag;
String num1,nan="NaN",max="∞",zero="0";
float result,zo=0;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);

 btnNum[0] = (Button) findViewById(R.id.btn0);  
        btnNum[1] = (Button) findViewById(R.id.btn1);  
        btnNum[2] = (Button) findViewById(R.id.btn2);  
        btnNum[3] = (Button) findViewById(R.id.btn3);  
        btnNum[4] = (Button) findViewById(R.id.btn4);  
        btnNum[5] = (Button) findViewById(R.id.btn5);  
        btnNum[6] = (Button) findViewById(R.id.btn6);  
        btnNum[7] = (Button) findViewById(R.id.btn7);  
        btnNum[8] = (Button) findViewById(R.id.btn8);  
        btnNum[9] = (Button) findViewById(R.id.btn9);  
        btnNum[10] = (Button) findViewById(R.id.dian);
        qiehuan = (Button) findViewById(R.id.qiehuan);
        edittext = (EditText) findViewById(R.id.edittext1);
        clear = (Button) findViewById(R.id.clear);
        del = (Button) findViewById(R.id.del);
        cheng = (Button) findViewById(R.id.cheng);
        chu = (Button) findViewById(R.id.chu);
        jian = (Button) findViewById(R.id.jian);
        jia = (Button) findViewById(R.id.jia);
        deng = (Button) findViewById(R.id.deng);
        textview = (TextView) findViewById(R.id.textview);

        edittext.setCursorVisible(false);    //隐藏光标
        edittext.setInputType(InputType.TYPE_NULL); // 关闭软键盘 
        edittext.setText("0");   //初始值        

        for(int i=0;i<=10;i++){//数字输入显示
        btnNum[i].setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Button btn = (Button) v;  
            String input = btn.getText().toString();
            String edittext_Value = edittext.getText().toString();  
            String textview_Value = textview.getText().toString();
            if( edittext_Value.equals(nan) || edittext_Value.equals(max) || edittext_Value.equals(zero)){
            edittext.setText("");
            }
            edittext.setText(edittext.getText().toString() + input);// 设置显示区域的值
}
}); 
        }

        clear.setOnClickListener(new OnClickListener() {    //清除键

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
edittext.setText("0");
textview.setText("");
}
});

        del.setOnClickListener(new OnClickListener() {//删除键

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String show = edittext.getText().toString();
int L = show.length();
if(L == 0){}
else if(L != 0){
edittext.setText(show.substring(0, L-1));
}

}
});

        jia.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
flag=1;
num1 = edittext.getText().toString();
edittext.setText(edittext.getText().toString() + "+");
}
});

        jian.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
flag=2;
num1 = edittext.getText().toString();
edittext.setText(edittext.getText().toString() + "-");
}
});

        cheng.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
flag=3;
num1 = edittext.getText().toString();
edittext.setText(edittext.getText().toString() + "×");
}
});

chu.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
flag=4;
num1 = edittext.getText().toString();
edittext.setText(edittext.getText().toString() + "÷");
}
});

/*public void dengdown(){
String num = edittext.getText().toString();
 if (num.indexOf("+") <= 0 && num.indexOf("-") <= 0 && num.indexOf("×") <= 0 && num.indexOf("÷") <= 0)
        {
 flag=5;
        }

}*/

deng.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String num = edittext.getText().toString();
String num2 = num.substring(num1.length()+1,num.length());
float numa = Float.parseFloat(num1);
float numb = Float.parseFloat(num2);
if(num.length()>0) {System.out.println("11111111");}

switch (flag) {
case 1:result = numa+numb;
break;
case 2:result = numa-numb;
break;
case 3:result = numa*numb;
break;
case 4:if(numa == 0 && numb == 0){
edittext.setText(nan);
}else if (numb == 0){
edittext.setText(max);
}
else  result = numa/numb;
break;
/*case 5:*/
default://dengdown();
break;
}
textview.setText(num+"=");
int re = (int)result;
float xiaoshu = result-re;
if(xiaoshu == zo){
edittext.setText(String.valueOf(re));
}else 
edittext.setText(String.valueOf(result));

}
});

qiehuan.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent it = new Intent(MainActivity.this,ScienceActivity.class);
startActivity(it);
}
});


}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){ 
if((System.currentTimeMillis()-exitTime) > 2000){ 
Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show(); 
exitTime = System.currentTimeMillis(); 
} else { 
finish(); 
System.exit(0); 
} 
return true; 
} 
return super.onKeyDown(keyCode, event); 
} 

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}


 

为了给Button加入以下效果使界面更美观，又写了三个XML文件：
 

android的简单计算器的实现
 

其中btneffect.xml如下，其他两个类似，如下：
 

 

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:state_pressed="false">
        <shape >
            <gradient android:startColor="#FAF0E6" android:endColor="#FAF0E6"
android:angle="270" />
<stroke android:width="1dip" android:color="#696969" />
<corners android:radius="10dp" />
<padding android:left="1dp" android:top="1dp"
android:right="1dp" android:bottom="1dp" />
        </shape>
    </item>

<item android:state_pressed="true">
        <shape >
            <gradient android:startColor="#DCDCDC" android:endColor="#DCDCDC"
android:angle="270" />
<stroke android:width="1dip" android:color="#000000" />
<corners android:radius="10dp" />
<padding android:left="1dp" android:top="1dp"
android:right="1dp" android:bottom="1dp" />
        </shape>
    </item>
</selector>




 

这就是简单计算器基本实现了，关于另外一个Activity的实现和这个基本类似，就不贴代码了。如有哪里写得不好或者有更好的想法，希望大家指正，本文仅作为新手们的交流。android的简单计算器的实现android的简单计算器的实现
 

 

 

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