Android studio实现简单的计算器
16lz
2021-01-23
目录
计算器1：
MainAcivity.java
activity_main.xml
UI界面
计算器2：
MainActivity.java:
active_main.xml:
UI界面：
计算器1：
MainAcivity.java
package com.example.lijiang.mycalculator;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.EditText;import java.lang.reflect.Method;import java.math.BigDecimal;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity{ private StringBuilder show_equation=new StringBuilder();//显示运算式 private ArrayList calculate_equation;//计算式 private int signal=0;//为0 时表示刚输入状态；为1 时表示当前在输出结果上继续输入 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //初始化 show_equation=new StringBuilder(); calculate_equation=new ArrayList<>(); Button zero=(Button)findViewById(R.id.zero); Button one=(Button)findViewById(R.id.one); Button two=(Button)findViewById(R.id.two); Button three=(Button)findViewById(R.id.three); Button four=(Button)findViewById(R.id.four); Button five=(Button)findViewById(R.id.five); Button six=(Button)findViewById(R.id.six); Button seven=(Button)findViewById(R.id.seven); Button eight=(Button)findViewById(R.id.eight); Button nine=(Button)findViewById(R.id.nine); Button cls=(Button)findViewById(R.id.cls); Button div=(Button)findViewById(R.id.div); Button mul=(Button)findViewById(R.id.mul); Button backspace=(Button)findViewById(R.id.Backspace); Button sub=(Button)findViewById(R.id.sub); Button add=(Button)findViewById(R.id.add); final Button equal=(Button)findViewById(R.id.equal); final Button point=(Button)findViewById(R.id.spot); final EditText result=(EditText)findViewById(R.id.result); result.setCursorVisible(true); disableShowInput(result); //点击文本框时光标始终在文本末尾 result.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { result.setSelection(result.getText().length()); } }); zero.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v){ if(!(show_equation.toString().equals("0"))){ if(signal==0){ show_equation.append("0"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("0"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } } }); one.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("1"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("1"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); two.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("2"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("2"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); three.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("3"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("3"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); four.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("4"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("4"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); five.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("5"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("5"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); six.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("6"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("6"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); seven.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("7"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("7"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); eight.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("8"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("8"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); nine.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ show_equation.append("9"); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); show_equation.append("9"); result.setText(show_equation); result.setSelection(result.getText().length()); signal=0; } } }); cls.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { show_equation.delete(0,show_equation.length()); calculate_equation.clear(); signal=0; result.setText(""); } }); backspace.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(!(show_equation.toString().equals(""))) { if(signal==0){ show_equation.deleteCharAt(show_equation.length() - 1); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ show_equation.delete(0,show_equation.length()); result.setText(""); signal=0; } } } }); point.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(signal==0){ String a=show_equation.toString(); if(a.equals("")){ show_equation.append("."); result.setText(show_equation); result.setSelection(result.getText().length()); }else{ int i; char t='0'; for(i=a.length();i>0;i--){ t=a.charAt(i-1); if(t=='.'||t=='+'||t=='-'||t=='*'||t=='/') break; } if(i==0){ show_equation.append("."); result.setText(show_equation); result.setSelection(result.getText().length()); }else if(t=='+'||t=='-'||t=='*'||t=='/'){ show_equation.append("."); result.setText(show_equation); result.setSelection(result.getText().length()); } } }else{ show_equation.delete(0,show_equation.length()); show_equation.append("."); result.setText("."); result.setSelection(result.getText().length()); signal=0; } } }); equal.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //判断用户是否输入了内容 if(!show_equation.toString().equals("")){ signal=1; char temp=show_equation.charAt(show_equation.length()-1); if(show_equation.charAt(0)=='-') show_equation.insert(0,"0"); if(temp=='+'||temp=='-') show_equation.append("0"); if(temp=='*'||temp=='/') show_equation.append("1"); StringBuilder temp1=new StringBuilder(); for(int i=0;i='0'&&show_equation.charAt(i)<='9'||show_equation.charAt(i)=='.'){ temp1.append(String.valueOf(show_equation.charAt(i))); }else if(show_equation.charAt(i)=='N'){ calculate_equation.add("NaN"); //跳过2个字符 i=i+2; }else if(show_equation.charAt(i)=='∞'){ calculate_equation.add("∞"); } else { if(temp1.length()!=0){ calculate_equation.add(temp1.toString()); temp1.delete(0,temp1.length()); } calculate_equation.add(String.valueOf(show_equation.charAt(i))); } } if(temp1.length()!=0){ calculate_equation.add(temp1.toString()); } calculate_equation.add("#"); String temp8=calculate(calculate_equation); result.setText(temp8); result.setSelection(result.getText().length()); show_equation.delete(0,show_equation.length()); calculate_equation.clear(); show_equation.append(temp8); } } }); add.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //判断用户是否输入了内容 if(!(show_equation.toString().equals(""))) { signal=0; char temp=show_equation.charAt(show_equation.length()-1); if(temp=='+'||temp=='-'||temp=='*'||temp=='/') { show_equation.deleteCharAt(show_equation.length()-1); show_equation.append("+"); } else show_equation.append("+"); result.setText(show_equation); result.setSelection(result.getText().length()); } } }); sub.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //判断用户是否输入了内容 if(!(show_equation.toString().equals(""))) { signal=0; char temp=show_equation.charAt(show_equation.length()-1); if(temp=='+'||temp=='-'||temp=='*'||temp=='/') { show_equation.deleteCharAt(show_equation.length()-1); show_equation.append("-"); } else show_equation.append("-"); result.setText(show_equation); result.setSelection(result.getText().length()); } } }); mul.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //判断用户是否输入了内容 if(!(show_equation.toString().equals(""))) { signal=0; char temp=show_equation.charAt(show_equation.length()-1); if(temp=='+'||temp=='-'||temp=='*'||temp=='/') { show_equation.deleteCharAt(show_equation.length()-1); show_equation.append("*"); } else show_equation.append("*"); result.setText(show_equation); result.setSelection(result.getText().length()); } } }); div.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //判断用户是否输入了内容 if(!(show_equation.toString().equals(""))) { signal=0; char temp=show_equation.charAt(show_equation.length()-1); if(temp=='+'||temp=='-'||temp=='*'||temp=='/') { show_equation.deleteCharAt(show_equation.length()-1); show_equation.append("/"); } else show_equation.append("/"); result.setText(show_equation); result.setSelection(result.getText().length()); } } }); } protected boolean operatorPriorityCompare(char operator1,char operator2) { int o1=0; int o2=0; switch (operator1){ case '+':{o1=0;break;} case '-':{o1=0;break;} case '*':{o1=1;break;} case '/':{o1=1;break;} } switch (operator2){ case '+':{o2=0;break;} case '-':{o2=0;break;} case '*':{o2=1;break;} case '/':{o2=1;break;} } if(o1<=o2) { return false; } else return true; } //相加 public static Double Add(Double d1,Double d2) { if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){ return d1+d2; } if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){ return d1+d2; } BigDecimal b1 = new BigDecimal(Double.toString(d1)); BigDecimal b2 = new BigDecimal(Double.toString(d2)); return b1.add(b2).doubleValue(); } //相减 public static Double Sub(Double d1,Double d2){ if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){ return d1-d2; } if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){ return d1-d2; } if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){ return d1*d2; } BigDecimal b1=new BigDecimal(Double.toString(d1)); BigDecimal b2=new BigDecimal(Double.toString(d2)); return b1.subtract(b2).doubleValue(); } //相乘 public static Double Mul(Double d1,Double d2){ if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){ return d1*d2; } if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){ return d1*d2; } BigDecimal b1=new BigDecimal(Double.toString(d1)); BigDecimal b2=new BigDecimal(Double.toString(d2)); return b1.multiply(b2).setScale(8).doubleValue(); } //相除 public static Double Div(Double d1,Double d2){ if(d1==Double.NEGATIVE_INFINITY||d1==Double.POSITIVE_INFINITY||d2==Double.NEGATIVE_INFINITY||d2==Double.POSITIVE_INFINITY){ return d1/d2; } if(String.valueOf(d1).equals("NaN")||String.valueOf(d1).equals("NaN")){ return d1/d2; } if(d1==0.0&&d2==0.0){ return Double.NaN; } if(d2==0.0){ return d1/d2; } BigDecimal b1=new BigDecimal(Double.toString(d1)); BigDecimal b2=new BigDecimal(Double.toString(d2)); return b1.divide(b2,8,BigDecimal.ROUND_HALF_UP).doubleValue(); } protected String calculate(ArrayList equation){ Double temp2; Double temp3; Double result; List operator=new ArrayList(); List operand=new ArrayList(); for(int i=0;i0) { String temp5=operator.get(operator.size()-1).toString(); while(!(operatorPriorityCompare(temp4.charAt(0),temp5.charAt(0)))&&operator.size()>0) { operator.remove(operator.size()-1); temp3=operand.get(operand.size()-1); operand.remove(operand.size()-1); temp2=operand.get(operand.size()-1); operand.remove(operand.size()-1); switch (temp5.charAt(0)){ case '+':{result=Add(temp2,temp3);operand.add(result);break;} case '-':{result=Sub(temp2,temp3);operand.add(result);break;} case '*':{result=Mul(temp2,temp3);operand.add(result);break;} case '/':{result=Div(temp2,temp3);operand.add(result);break;} } if(operator.size()>0) { temp5=operator.get(operator.size()-1).toString(); } else break; } operator.add(temp4); } else operator.add(temp4); } else if(temp4.equals("#")) { while(operator.size()>0) { String temp6=(String)operator.get(operator.size()-1); operator.remove(operator.size()-1); temp3=operand.get(operand.size()-1); operand.remove(operand.size()-1); temp2=operand.get(operand.size()-1); operand.remove(operand.size()-1); switch (temp6.charAt(0)){ case '+':{result=Add(temp2,temp3);operand.add(result);break;} case '-':{result=Sub(temp2,temp3);operand.add(result);break;} case '*':{result=Mul(temp2,temp3);operand.add(result);break;} case '/':{result=Div(temp2,temp3);operand.add(result);break;} } } } else { if(temp4.equals("NaN")){ operand.add(Double.NaN); }else if(temp4.equals("∞")){ operand.add(Double.POSITIVE_INFINITY); }else{ operand.add(Double.parseDouble(temp4)); } } } if(operand.get(0)==Double.NEGATIVE_INFINITY) return "-∞"; if(operand.get(0)==Double.POSITIVE_INFINITY) return "∞"; return operand.get(0).toString(); } //当API最低版小于21时使用这个函数实现点击文本框不弹出键盘 public void disableShowInput(EditText et) { Class cls = EditText.class; Method method; try { method = cls.getMethod("setShowSoftInputOnFocus", boolean.class); method.setAccessible(true); method.invoke(et, false); } catch (Exception e) { e.printStackTrace(); } }} activity_main.xml
<?xml version="1.0" encoding="utf-8"?> UI界面
计算器2：
MainActivity.java:
package com.example.yuanmei.yuanmeicalculatorproject;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;public class MainActivity extends Activity { private TextView textView; private String str,num1,num2; private double result; private boolean addNum; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); textView = (TextView) findViewById(R.id.textView); addNum = true; } public void onClick(View v){ str = (String) textView.getText(); switch (v.getId()) { case R.id.btn_cle: textView.setText(""); break; case R.id.btn_del: if(!str.equals("") && str != null){ textView.setText(str.substring(0, str.length()-1)); } break; case R.id.btn_equ: if(str.contains("+")){ getResult(num1, num2, "+"); } else if(str.contains("-")){ getResult(num1, num2, "-"); } else if(str.contains("×")){ getResult(num1, num2, "×"); } else if(str.contains("÷")){ getResult(num1, num2, "÷"); } else { return; } break; case R.id.btn_add: case R.id.btn_sub: case R.id.btn_mul: case R.id.btn_div: if (str.contains("+")||str.contains("-")||str.contains("×")||str.contains("÷")) return; else textView.setText(str+((Button)v).getText()); if(!addNum) addNum = true; break; default: if (addNum) { textView.setText(str+((Button)v).getText()); }else{ textView.setText(((Button)v).getText()); addNum = true; } break; } } private void getResult(String num1,String num2,String op) { num1 = str.substring(0,str.indexOf(op)); num2 = str.substring(str.indexOf(op)+1); try { double n1 = Double.parseDouble(num1); double n2 = Double.parseDouble(num2); if (op.equals("+")) { result = n1+n2; }else if(op.equals("-")){ result = n1-n2; }else if(op.equals("×")){ result = n1*n2; }else if(op.equals("÷")){ result = n1/n2; }else { return; } String r = result+""; if(r.contains(".")&&r.substring(r.length()-1).equals("0")){ r = r.substring(0,r.indexOf(".")); } textView.setText(r); addNum = false; } catch (Exception e) { return; } }}active_main.xml:
<?xml version="1.0" encoding="utf-8"?> UI界面：
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