本文實例為大家分享了android studio實現計算器的具體代碼,供大家參考,具體內容如下
先來個效果圖:
功能: 滿足加減乘除四則運算規則,有回退、清除功能。
下面的代碼只是完成基本功能,若添加背景圖先看看下面的方法:
Android Studio App設置背景圖片
1、本地準備好圖片,複製它,粘貼進mipmap(drawable)文件夾。
2、在activity_main.xml裡添加下面代碼,注意添加位置。
3、完成,效果圖:
content_main.xml文件(頁面佈局,content_main.xml代碼包含在activity_main.xml文件中):
-->
strings.xml(content_main.xml代碼中的一些變量在此代碼中定義的):
CalculatorSettingspage2下一頁0123456789+-*/CE<-=請輸入:結果:.計算式
MainActivity.Java(計算器中實現計算功能的核心代碼):
package com.example.dell.calculator; import android.content.Intent; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.app.Activity; import android.content.Context; import android.view.View.OnClickListener; import android.widget.CheckBox; import android.widget.EditText; import android.widget.Button; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.text.DecimalFormat; import java.text.NumberFormat; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MainActivity extends AppCompatActivity { private EditText output = null; private EditText input = null; private Button btn0 = null; private Button btn1 = null; private Button btn2 = null; private Button btn3 = null; private Button btn4 = null; private Button btn5 = null; private Button btn6 = null; private Button btn7 = null; private Button btn8 = null; private Button btn9 = null; private Button btnadd = null; private Button btnsubtract = null; private Button btnmultiply = null; private Button btndivide = null; private Button btnclear = null; private Button btnback = null; private Button btndot = null; private Button btnresult = null; private String text = "";//保存輸入的數字和符號 private Double result = 0.0;//輸出結果 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); output = (EditText) findViewById(R.id.output); input = (EditText) findViewById(R.id.input); btn0 = (Button) findViewById(R.id.zero); btn1 = (Button) findViewById(R.id.one); btn2 = (Button) findViewById(R.id.two); btn3 = (Button) findViewById(R.id.three); btn4 = (Button) findViewById(R.id.four); btn5 = (Button) findViewById(R.id.five); btn6 = (Button) findViewById(R.id.six); btn7 = (Button) findViewById(R.id.seven); btn8 = (Button) findViewById(R.id.eight); btn9 = (Button) findViewById(R.id.nine); btnadd = (Button) findViewById(R.id.add); btnsubtract = (Button) findViewById(R.id.subtract); btnmultiply = (Button) findViewById(R.id.multiply); btndivide = (Button) findViewById(R.id.divide); btnclear = (Button) findViewById(R.id.clear); btnback = (Button) findViewById(R.id.back); btndot = (Button) findViewById(R.id.dot); btnresult = (Button) findViewById(R.id.result); //設置按鈕偵聽事件 btn0.setOnClickListener(listener); btn1.setOnClickListener(listener); btn2.setOnClickListener(listener); btn3.setOnClickListener(listener); btn4.setOnClickListener(listener); btn5.setOnClickListener(listener); btn6.setOnClickListener(listener); btn7.setOnClickListener(listener); btn8.setOnClickListener(listener); btn9.setOnClickListener(listener); btnadd.setOnClickListener(listener); btnsubtract.setOnClickListener(listener); btnmultiply.setOnClickListener(listener); btndivide.setOnClickListener(listener); btnclear.setOnClickListener(listener); btnback.setOnClickListener(listener); btndot.setOnClickListener(listener); btnresult.setOnClickListener(listener); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) .setAction("Action", null).show(); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } //public void onClickNext(View view) { // Intent intent = new Intent(this,page2.class); // startActivity(intent); // } private OnClickListener listener = new OnClickListener() { public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { //輸入數字 case R.id.zero: num(0); break; case R.id.one: num(1); break; case R.id.two: num(2); break; case R.id.three: num(3); break; case R.id.four: num(4); break; case R.id.five: num(5); break; case R.id.six: num(6); break; case R.id.seven: num(7); break; case R.id.eight: num(8); break; case R.id.nine: num(9); break; case R.id.dot: dot(); break; //執行運算 case R.id.add: add(); break; case R.id.subtract: sub(); break; case R.id.multiply: multiply(); break; case R.id.divide: divide(); break; case R.id.clear: clear(); break; case R.id.back: back(); break; //計算結果 case R.id.result: result(); break; default: break; } input.setText(text); output.setText(String.valueOf(result)); } }; private void num(int i) { // TODO Auto-generated method stub text = text + String.valueOf(i); } private void dot() { // TODO Auto-generated method stub text = text + "."; } private void clear() { // TODO Auto-generated method stub text = ""; result = null; input.setText(""); output.setText(""); } private void back() { // TODO Auto-generated method stub String str = text.substring(0, text.length()-1); text = str; } private void add() { // TODO Auto-generated method stub text += "+"; } private void sub() { // TODO Auto-generated method stub text += "-"; } private void multiply() { // TODO Auto-generated method stub text += "*"; } private void divide() { // TODO Auto-generated method stub text += "/"; } //計算輸出結果 private void result() { // TODO Auto-generated method stub result = testOperation(text); } public Double testOperation(String s){ //分割字符然後放進數組 String s1 =s.replace("+","-"); String[] str = s1.split("-"); double total1=0; //先遍歷數組,把裡面的乘除結果算出來 for(String str1:str){ if(str1.contains("*")||str1.contains("/")){ double total = 0; for(int i =0;i<str1.length();){ int count =1; a:for(int j =i+1;j<str1.length();j++){ char c =str1.charAt(j); if(c=='*'||c=='/'){ break a; }else{ count++; } } //將數字截取出來 String s2 =str1.substring(i,i+count); double d = Double.parseDouble(s2); if(i==0){ total = d; }else{ char c1 = str1.charAt(i-1); if(c1=='*'){ total*=d; }else if(c1=='/'){ //如果除數為0,直接返回null; if(d == 0) return null; total/=d; } } i+=count+1; } s= s.replace(str1, total+""); } } //進行加減運算 for(int i =0;i<s.length();i++){ int count =1; a:for(int j=i+1;j<s.length();j++){ char c = s.charAt(j); if(c=='+'||c=='-'){ break a; }else{ count++; } } String s3= s.substring(i,i+count); double d2 = Double.parseDouble(s3); if(i==0){ total1 = d2; }else{ char c = s.charAt(i-1); if(c=='+'){ total1+=d2; }else if(c=='-'){ total1-=d2; } } i+=count; } return total1; } }
更多計算器功能實現,請點擊專題: 計算器功能彙總 進行學習
關於Android計算器功能的實現,查看專題:Android計算器 進行學習。
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