Android studio设计简易计算器

<?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_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity" android:background="#000000">  <TextView  android:id="@+id/text1"  android:layout_width="match_parent"  android:layout_height="170dp"  android:layout_marginLeft="10dp"  android:layout_marginTop="10dp"  android:layout_marginRight="10dp"  android:background="#ffffff"  android:gravity="right|bottom"  android:hint="0"  android:paddingRight="5dp"  android:textColor="#000000"  android:textSize="40sp" /> <LinearLayout  android:id="@+id/relative"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:layout_marginTop="10dp"  android:layout_marginRight="10dp"  android:layout_marginLeft="10dp"  android:orientation="vertical">   <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content">  <Button   android:id="@+id/btn_7"   style="@style/ButtonStyle"   android:text="@string/btn_7" />  <Button   android:id="@+id/btn_8"   style="@style/ButtonStyle"   android:text="@string/btn_8" />  <Button   android:id="@+id/btn_9"   style="@style/ButtonStyle"   android:text="@string/btn_9" />  <Button   android:id="@+id/btn_clear"   style="@style/ButtonStyle"   android:text="@string/btn_clear"/> </LinearLayout>  <LinearLayout   android:layout_width="match_parent"   android:layout_height="wrap_content">   <Button    android:id="@+id/btn_4"    style="@style/ButtonStyle"    android:text="@string/btn_4" />   <Button    android:id="@+id/btn_5"    style="@style/ButtonStyle"    android:text="@string/btn_5" />   <Button    android:id="@+id/btn_6"    style="@style/ButtonStyle"    android:text="@string/btn_6" />   <Button    android:id="@+id/btn_plus"    style="@style/ButtonStyle"    android:text="@string/btn_plus"/>  </LinearLayout>  <LinearLayout   android:layout_width="match_parent"   android:layout_height="wrap_content">   <Button    android:id="@+id/btn_1"    style="@style/ButtonStyle"    android:text="@string/btn_1" />   <Button    android:id="@+id/btn_2"    style="@style/ButtonStyle"    android:text="@string/btn_2" />   <Button    android:id="@+id/btn_3"    style="@style/ButtonStyle"    android:text="@string/btn_3" />   <Button    android:id="@+id/btn_minus"    style="@style/ButtonStyle"    android:text="@string/btn_minus"/>  </LinearLayout>  <LinearLayout   android:layout_width="match_parent"   android:layout_height="wrap_content">   <Button    android:id="@+id/btn_0"    style="@style/ButtonStyle"    android:text="@string/btn_0" />   <Button    android:id="@+id/btn_equal"    style="@style/ButtonEqualStyle"    android:text="@string/btn_equal" />   <Button    android:id="@+id/btn_divide"    style="@style/ButtonStyle"    android:text="@string/btn_divide" />   <Button    android:id="@+id/btn_multiply"    style="@style/ButtonStyle"    android:text="@string/btn_multiply"/>  </LinearLayout> </LinearLayout> </LinearLayout>

<resources> <string name="app_name">计算器</string> <string name="text1">显示文本框</string> <string name="relative">布局</string> <string name="btn_1">1</string> <string name="btn_2">2</string> <string name="btn_3">3</string> <string name="btn_4">4</string> <string name="btn_5">5</string> <string name="btn_6">6</string> <string name="btn_7">7</string> <string name="btn_8">8</string> <string name="btn_9">9</string> <string name="btn_0">0</string> <string name="btn_clear">C</string> <string name="btn_plus">+</string> <string name="btn_minus">-</string> <string name="btn_multiply">×</string> <string name="btn_divide">÷</string> <string name="btn_equal">=</string></resources>

<resources> <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">  <!-- Customize your theme here. -->  <item name="colorPrimary">@color/colorPrimary</item>  <item name="colorPrimaryDark">@color/colorPrimaryDark</item>  <item name="colorAccent">@color/colorAccent</item> </style> <style name="ButtonBaseStyle">  <item name="android:layout_width">40dp</item>  <item name="android:layout_height">70dp</item>  <item name="android:layout_margin">10dp</item>  <item name="android:padding">10dp</item>  <item name="android:textColor">@android:color/black</item>  <item name="android:textSize">30sp</item> </style> <style name="ButtonStyle" parent="ButtonBaseStyle">  <item name="android:background">@drawable/bg_selector</item>  <item name="android:layout_weight">1</item> </style> <style name="ButtonEqualStyle" parent="ButtonBaseStyle">  <item name="android:background">@drawable/ping_bg</item>  <item name="android:layout_weight">1</item> </style></resources>

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"><corners android:radius="5dp"/> <solid android:color="#ffffff"/></shape>

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"><corners android:radius="5dp"></corners> <solid android:color="#ee82ee"></solid></shape>

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@drawable/white_bg" android:state_pressed="false"></item> <item android:drawable="@drawable/ping_bg"  android:state_pressed="true"></item></selector>

package com.example.exp3;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.text.TextUtils;import android.view.View;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;import java.util.regex.Matcher;import java.util.regex.Pattern; public class MainActivity extends AppCompatActivity implements View.OnClickListener { @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  int[] ids = {R.id.btn_0, R.id.btn_1, R.id.btn_2, R.id.btn_3, R.id.btn_4, R.id.btn_4,    R.id.btn_5, R.id.btn_6, R.id.btn_7, R.id.btn_8, R.id.btn_9, R.id.btn_equal,    R.id.btn_clear, R.id.btn_multiply, R.id.btn_minus, R.id.btn_divide, R.id.btn_plus};  //将所有按钮整合成一个数组  for (int i = 0; i < ids.length; i++)   findViewById(ids[i]).setOnClickListener(this);//给每个按钮设置一个监听事件 } @Override public void onClick(View v) {  TextView tv_input = (TextView) findViewById(R.id.text1);  Button btn = (Button)v;  String str=tv_input.getText().toString();//获取xml那里的输入  String strButton =btn.getText().toString();//点击按钮得到的文本  switch (v.getId()){   case R.id.btn_0:   case R.id.btn_1:   case R.id.btn_2:   case R.id.btn_3:   case R.id.btn_4:   case R.id.btn_5:   case R.id.btn_6:   case R.id.btn_7:   case R.id.btn_8:   case R.id.btn_9:    if (str.equals("0"))     tv_input.setText(strButton);    else     tv_input.setText(str+strButton);    break;   case R.id.btn_clear:    tv_input.setText("0");    break;   case R.id.btn_plus:   case R.id.btn_minus:   case R.id.btn_multiply:   case R.id.btn_divide:    tv_input.setText(str+strButton);    break;   case R.id.btn_equal:    MyCalc obj=new MyCalc(str);    double ret = obj.Calc();    int Ret = (int)ret;    if (ret == Ret)     tv_input.setText(String.valueOf(Ret));    else     tv_input.setText(String.valueOf(ret));    break;  } }  class MyCalc {  private String input;   public MyCalc(String input) {   this.input = input;  }   public double Calc() {   if (TextUtils.isEmpty(input))    return 0;   Pattern pattern = Pattern.compile("[+(×)(÷)/-]");   String[] nums = pattern.split(input);   Matcher matcher = pattern.matcher(input);   if (matcher.find() == false)    return 0;   String op = matcher.group(0);   double first = Double.parseDouble(nums[0]);   double second = Double.parseDouble(nums[1]);   double sum = 0;   try {    switch (op) {     case "+":      sum = first + second;      break;     case "-":      sum = first - second;      break;     case "×":      sum = first * second;      break;     case "÷":      sum = first / second;      break;    }   } catch (Exception e) {    Toast.makeText(MainActivity.this, "出错", Toast.LENGTH_LONG).show();   }   return sum;  } }}