android studio实现计算器

<?xml version="1.0" encoding="utf-8"?><resources>  <color name="colorPrimary">#3F51B5</color>  <color name="colorPrimaryDark">#303F9F</color>  <color name="colorAccent">#FF4081</color>  <color name="white">#FFFFFF</color>  <color name="black">#000000</color>  <color name="zi">#FFFFFF</color>  <color name="gray">#BEBEBE</color>  <color name="green">#9AFF9A</color>  <color name="littlegreen">#F0FFFF</color></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="@color/white"/></shape>

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

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

<?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"  android:background="@drawable/jisuanqi"  tools:context="com.example.administrator.calculate.MainActivity"  >  <LinearLayout    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:layout_marginTop="30dp"    android:paddingLeft="20dp"    android:paddingRight="20dp"    android:paddingTop="20dp">    <EditText      android:id="@+id/input"      android:layout_width="fill_parent"      android:layout_height="60dp"      android:background="@drawable/white"      android:editable="false"      android:gravity="right|bottom"      />  </LinearLayout>  <LinearLayout  android:layout_width="fill_parent"  android:layout_height="wrap_content"  android:layout_marginTop="20dp"  android:orientation="horizontal"  android:gravity="center">  <Button    android:layout_width="65dp"    android:layout_height="65dp"    android:text="C"    android:background="@drawable/selector"    android:gravity="center"    android:textSize="25sp"    android:id="@+id/clear"    />  <Button    android:layout_width="65dp"    android:layout_height="65dp"    android:text="←"    android:background="@drawable/selector"    android:gravity="center"    android:layout_marginLeft="10dp"    android:textSize="23sp"    android:id="@+id/delete"    />  <Button    android:layout_width="65dp"    android:layout_height="65dp"    android:text="×"    android:background="@drawable/selector"    android:gravity="center"    android:layout_marginLeft="10dp"    android:textSize="25sp"    android:id="@+id/cheng"    />  <Button    android:layout_width="65dp"    android:layout_height="65dp"    android:text="÷"    android:background="@drawable/selector"    android:gravity="center"    android:layout_marginLeft="10dp"    android:textSize="25sp"    android:id="@+id/clu"    /></LinearLayout>  <LinearLayout    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:layout_marginTop="20dp"    android:orientation="horizontal"    android:gravity="center">    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="7"      android:background="@drawable/selector"      android:gravity="center"      android:textSize="25sp"      android:id="@+id/num7"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="8"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/num8"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="9"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/num9"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="－"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/charjian"      />  </LinearLayout>  <LinearLayout    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:layout_marginTop="20dp"    android:orientation="horizontal"    android:gravity="center">    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="4"      android:background="@drawable/selector"      android:gravity="center"      android:textSize="25sp"      android:id="@+id/num4"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="5"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/num5"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="6"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/num6"      />    <Button      android:layout_width="65dp"      android:layout_height="65dp"      android:text="＋"      android:background="@drawable/selector"      android:gravity="center"      android:layout_marginLeft="10dp"      android:textSize="25sp"      android:id="@+id/charadd"      />  </LinearLayout>  <LinearLayout    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:orientation="horizontal"    android:gravity="center_horizontal"    android:layout_marginTop="10dp"    >    <LinearLayout      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:orientation="vertical"      >      <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="horizontal"        >        <Button          android:layout_width="65dp"          android:layout_height="65dp"          android:background="@drawable/selector"          android:text="1"          android:gravity="center"          android:textSize="25sp"          android:id="@+id/num1"          />        <Button          android:layout_width="65dp"          android:layout_height="65dp"          android:text="2"          android:background="@drawable/selector"          android:gravity="center"          android:layout_marginLeft="10dp"          android:textSize="25sp"          android:id="@+id/num2"/>        <Button          android:layout_width="65dp"          android:layout_height="65dp"          android:text="3"          android:background="@drawable/selector"          android:gravity="center"          android:layout_marginLeft="10dp"          android:textSize="25sp"          android:id="@+id/num3"/>      </LinearLayout>      <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="horizontal"        android:layout_marginTop="10dp">        <Button          android:id="@+id/num0"          android:layout_width="140dp"          android:layout_height="65dp"          android:text="0"          android:background="@drawable/selector"          android:gravity="center"          android:textSize="25sp" />        <Button          android:id="@+id/dian"          android:layout_width="65dp"          android:layout_height="65dp"          android:layout_marginLeft="10dp"          android:background="@drawable/selector"          android:gravity="center"          android:text="."          android:textSize="25sp" />      </LinearLayout>    </LinearLayout>    <LinearLayout      android:layout_width="wrap_content"      android:layout_height="wrap_content">      <Button        android:layout_width="65dp"        android:layout_height="140dp"        android:text="="        android:background="@drawable/equal"        android:gravity="center"        android:layout_marginLeft="10dp"        android:textSize="25sp"        android:id="@+id/equai"/>    </LinearLayout>  </LinearLayout></LinearLayout>

package com.example.administrator.calculate;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.LinearLayout;import android.widget.Toast;import butterknife.BindView;import butterknife.ButterKnife;import butterknife.OnClick;public class MainActivity extends AppCompatActivity {  @BindView(R.id.input)  EditText input;  @BindView(R.id.clear)  Button clear;  @BindView(R.id.delete)  Button delete;  @BindView(R.id.cheng)  Button cheng;  @BindView(R.id.clu)  Button chu;  @BindView(R.id.num7)  Button num7;  @BindView(R.id.num8)  Button num8;  @BindView(R.id.num9)  Button num9;  @BindView(R.id.charjian)  Button charjian;  @BindView(R.id.num4)  Button num4;  @BindView(R.id.num5)  Button num5;  @BindView(R.id.num6)  Button num6;  @BindView(R.id.charadd)  Button charadd;  @BindView(R.id.num1)  Button num1;  @BindView(R.id.num2)  Button num2;  @BindView(R.id.num3)  Button num3;  @BindView(R.id.num0)  Button num0;  @BindView(R.id.dian)  Button dian;  @BindView(R.id.equai)  Button equal;  private String ss="";  private boolean fu=false;  private boolean num=false;  private boolean point=false;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    ButterKnife.bind(this);  }  @OnClick({R.id.clear, R.id.delete, R.id.cheng, R.id.clu, R.id.num7, R.id.num8, R.id.num9, R.id.charjian, R.id.num4, R.id.num5, R.id.num6, R.id.charadd, R.id.num1, R.id.num2, R.id.num3, R.id.num0, R.id.dian, R.id.equai})  public void onViewClicked(View view) {    switch (view.getId()) {      case R.id.clear:      {        ss="";        input.setText(ss);      }        break;      case R.id.delete:      {        if(ss.indexOf(" ")==ss.length()-3)        {          ss= ss.substring(0,ss.length() - 2);        }        if(ss.length()>0)        {          ss= ss.substring(0,ss.length() - 1);        }        input.setText(ss);      }        break;      case R.id.cheng:      {        if(ss.length()==0)        {          break;        }        if(ss.contains(" "))        {          if(ss.indexOf(" ")==ss.length()-3||ss.indexOf(" ")==ss.length()-2||ss.indexOf(" ")==ss.length()-1) break;          getResult();        }        fu=true;        ss+=" × ";        input.setText(ss);      }        break;      case R.id.clu:      {        if(ss.length()==0)        {          break;        }        if(ss.contains(" "))        {          if(ss.indexOf(" ")==ss.length()-3||ss.indexOf(" ")==ss.length()-2||ss.indexOf(" ")==ss.length()-1) break;          getResult();        }        fu=true;        ss+=" ÷ ";        input.setText(ss);      }        break;      case R.id.num7:      {        ss+="7";        input.setText(ss);      }        break;      case R.id.num8:      {        ss+="8";        input.setText(ss);      }        break;      case R.id.num9:      {        ss+="9";        input.setText(ss);      }        break;      case R.id.charjian:      {        if(ss.length()==0)        {          break;        }        if(ss.contains(" "))        {          if(ss.indexOf(" ")==ss.length()-3||ss.indexOf(" ")==ss.length()-2||ss.indexOf(" ")==ss.length()-1) break;          getResult();        }        fu=true;        ss+=" － ";        input.setText(ss);      }        break;      case R.id.num4:      {        ss+="4";        input.setText(ss);      }        break;      case R.id.num5:      {        ss+="5";        input.setText(ss);      }        break;      case R.id.num6:      {        ss+="6";        input.setText(ss);      }        break;      case R.id.charadd:      {        if(ss.length()==0)        {          break;        }        if(ss.contains(" "))        {          if(ss.indexOf(" ")==ss.length()-3||ss.indexOf(" ")==ss.length()-2||ss.indexOf(" ")==ss.length()-1) break;          getResult();        }        fu=true;        ss+=" ＋ ";        input.setText(ss);      }        break;      case R.id.num1:      {        ss+="1";        input.setText(ss);      }        break;      case R.id.num2:      {        ss+="2";        input.setText(ss);      }        break;      case R.id.num3:      {        ss+="3";        input.setText(ss);      }        break;      case R.id.num0:      {        ss+="0";        input.setText(ss);      }        break;      case R.id.dian:      {        if(ss.length()==0||ss.indexOf(" ")==ss.length()-3||ss.lastIndexOf(".")>ss.indexOf(" "))        {          break;        }        else        {          ss+=".";          input.setText(ss);        }      }        break;      case R.id.equai:        getResult();        break;    }  }  private void getResult()  {    double result=0;    if(ss==null||ss.equals("")) return;    if(!ss.contains(" ")) return;    String s1=ss.substring(0,ss.indexOf(" "));    String op=ss.substring(ss.indexOf(" ")+1,ss.indexOf(" ")+2);    String s2=ss.substring(ss.indexOf(" ")+3);    if(!s1.equals("")&&!s2.equals(""))    {      double d1=Double.parseDouble(s1);      double d2=Double.parseDouble(s2 );      switch (op)      {        case "＋": result=d1+d2;break;        case "－": result=d1-d2;break;        case "×": result=d1*d2;break;        case "÷":        {          if(d2==0)          {            Toast.makeText(this, "不能除以零", Toast.LENGTH_SHORT).show();            break;          }          result=d1/d2*1.0;        }        break;      }      int r = (int) result;      if(r==result)      {        input.setText(""+r);        ss=""+r;      }      else      {        input.setText(result+"");        ss=""+result;      }    }  }}

android:theme=”@style/Theme.AppCompat.DayNight.NoActionBar”