package com.imooc.calculator;
import java.util.ArrayList;
import java.util.Arrays;
import bsh.EvalError;
import bsh.Interpreter;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity implements OnClickListener {
Button btn_0;
Button btn_1;
Button btn_2;
Button btn_3;
Button btn_4;
Button btn_5;
Button btn_6;
Button btn_7;
Button btn_8;
Button btn_9;
Button btn_point;// 小数点
Button btn_divide;// 除以
Button btn_multiply;// 乘以
Button btn_minus;// 减去
Button btn_pluse;// 加
Button btn_equal;// 等于
Button btn_clear;
Button btn_del;
private EditText et_showview;
boolean needclear;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_0 = (Button) findViewById(R.id.btn_0);
btn_1 = (Button) findViewById(R.id.btn_1);
btn_2 = (Button) findViewById(R.id.btn_2);
btn_3 = (Button) findViewById(R.id.btn_3);
btn_4 = (Button) findViewById(R.id.btn_4);
btn_5 = (Button) findViewById(R.id.btn_5);
btn_6 = (Button) findViewById(R.id.btn_6);
btn_7 = (Button) findViewById(R.id.btn_7);
btn_8 = (Button) findViewById(R.id.btn_8);
btn_9 = (Button) findViewById(R.id.btn_9);
btn_point = (Button) findViewById(R.id.btn_point);// 小数点
btn_divide = (Button) findViewById(R.id.btn_divide);// 除以
btn_multiply = (Button) findViewById(R.id.btn_multiply);// 乘以
btn_minus = (Button) findViewById(R.id.btn_minus);// 减去
btn_pluse = (Button) findViewById(R.id.btn_pluse);// 加
btn_equal = (Button) findViewById(R.id.btn_equal);// 等于
btn_clear = (Button) findViewById(R.id.btn_clear);
btn_del = (Button) findViewById(R.id.btn_del);
et_showview = (EditText) findViewById(R.id.et_showview);
btn_0.setOnClickListener(this);
btn_1.setOnClickListener(this);
btn_2.setOnClickListener(this);
btn_3.setOnClickListener(this);
btn_4.setOnClickListener(this);
btn_5.setOnClickListener(this);
btn_6.setOnClickListener(this);
btn_7.setOnClickListener(this);
btn_8.setOnClickListener(this);
btn_9.setOnClickListener(this);
btn_point.setOnClickListener(this);
btn_divide.setOnClickListener(this);
btn_multiply.setOnClickListener(this);
btn_minus.setOnClickListener(this);
btn_pluse.setOnClickListener(this);
btn_equal.setOnClickListener(this);
btn_clear.setOnClickListener(this);
btn_del.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String str = et_showview.getText().toString();
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:
case R.id.btn_point:
if(needclear){
needclear=false;
str = "";
et_showview.setText("");
}
et_showview.setText(str + ((Button) v).getText());
break;
case R.id.btn_pluse:
case R.id.btn_minus:
case R.id.btn_multiply:
case R.id.btn_divide:
if(needclear){
needclear=false;
str = "";
et_showview.setText("");
}
et_showview.setText(str +" "+((Button) v).getText()+" ");
break;
case R.id.btn_equal:
getResult();
break;
case R.id.btn_del:
if(str != null && !str.equals("")) {
et_showview.setText(str.substring(0, str.length() - 1));
}
break;
case R.id.btn_clear:
needclear=false;
str = "";
et_showview.setText("");
break;
}
}
/**
* 获取计算结果
*/
private void getResult() {
needclear = true;
String exp = et_showview.getText().toString();
double r = 0;
//当我们的输入框是null或者""时我们不进行操作
if (exp == null || exp.equals(" ")) {
return;
}
//要计算结果，必须知道输入框是否有操作符，判断条件就是前后是否在空格，否则不进行操作
if (!exp.contains(" ")) {
//没有运算符，所以不用运算
return;
}
int space = exp.indexOf(' ');//用于搜索空格位置
String s1 = exp.substring(0, space);//s1用于保存第一个运算数
String op = exp.substring(space + 1, space + 2);//op用于保存运算符
String s2 = exp.substring(space + 3);//s2用于保存第二个运算数
double arg1 = Double.parseDouble(s1);//将运算数从string转换为Single
double arg2 = Double.parseDouble(s2);
if(op.equals("＋")){
r = arg1 + arg2;
}else if(op.equals("－")){
r = arg1 - arg2;
}else if(op.equals("×")){
r = arg1 * arg2;
}else if(op.equals("÷")){
//除数为0不计算
if (arg2 == 0)
{
AlertDialog.Builder builder = new Builder(MainActivity.this);
builder.setTitle("警告" ) ;
builder.setMessage("零不能做分母" ) ;
builder.setPositiveButton("确定" , null );
builder.show();
}
else
{
r = arg1 / arg2;
}
}
if(!s1.contains(".")&&!s2.contains(".")){
int result = (int)r;
et_showview.setText(result+"");
}else{
et_showview.setText(r+"");
}
}
}
