标签：
xml布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal" >
<EditText
android:id="@+id/show"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="10dp"
android:editable="false"
android:gravity="right"
android:hint="@string/class3_1" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_marginBottom="15dp"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:layout_marginTop="10dp"
android:layout_weight="6"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="3"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
<Button
android:id="@+id/bt_c"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="C" />
<Button
android:id="@+id/bt_del"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="DEL" />
<Button
android:id="@+id/bt_d"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="÷" />
<Button
android:id="@+id/bt_m"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="×" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
<Button
android:id="@+id/bt_7"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="7" />
<Button
android:id="@+id/bt_8"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="8" />
<Button
android:id="@+id/bt_9"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="9" />
<Button
android:id="@+id/bt_di"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="-" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
<Button
android:id="@+id/bt_4"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="4" />
<Button
android:id="@+id/bt_5"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="5" />
<Button
android:id="@+id/bt_6"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="6" />
<Button
android:id="@+id/bt_a"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="+" />
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="2"
android:orientation="horizontal" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="3"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal" >
<Button
android:id="@+id/bt_1"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="1" />
<Button
android:id="@+id/bt_2"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="2" />
<Button
android:id="@+id/bt_3"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="3" />
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:orientation="horizontal" >
<Button
android:id="@+id/bt_0"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="2"
android:text="0" />
<Button
android:id="@+id/bt_p"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="." />
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:orientation="vertical" >
<Button
android:id="@+id/bt_e"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="＝" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
</LinearLayout>
j
java 代码：
package com.example.class3;
import java.util.Stack;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import com.example.lesson.R;
public class Activity3 extends Activity implements OnClickListener {
private EditText show;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.class3_1);
show = (EditText) findViewById(R.id.show);
/*
* 数字键监听
*/
findViewById(R.id.bt_0).setOnClickListener(this);
findViewById(R.id.bt_1).setOnClickListener(this);
findViewById(R.id.bt_2).setOnClickListener(this);
findViewById(R.id.bt_3).setOnClickListener(this);
findViewById(R.id.bt_4).setOnClickListener(this);
findViewById(R.id.bt_5).setOnClickListener(this);
findViewById(R.id.bt_6).setOnClickListener(this);
findViewById(R.id.bt_7).setOnClickListener(this);
findViewById(R.id.bt_8).setOnClickListener(this);
findViewById(R.id.bt_9).setOnClickListener(this);
/*
* 功能键监听
*/
findViewById(R.id.bt_c).setOnClickListener(this);
findViewById(R.id.bt_p).setOnClickListener(this);
findViewById(R.id.bt_del).setOnClickListener(this);
findViewById(R.id.bt_e).setOnClickListener(this);
/*
* 运算符监听
*/
findViewById(R.id.bt_di).setOnClickListener(this);
findViewById(R.id.bt_d).setOnClickListener(this);
findViewById(R.id.bt_a).setOnClickListener(this);
findViewById(R.id.bt_m).setOnClickListener(this);
}
public void onClick(View view) {
switch (view.getId()) {
case R.id.bt_c:
show.setText("");
break;
case R.id.bt_del:
String text = show.getText().toString();
text = (String) text.subSequence(0, text.length() - 1);
show.setText(text);
break;
case R.id.bt_e:
Calculate();
break;
default:
Button button = (Button) findViewById(view.getId());
show.setText(show.getText() + "" + button.getText());
break;
}
}
private void Calculate() {
Stack<Double> num = new Stack<Double>();
Stack<Character> operator = new Stack<Character>();
char[] op = { ‘#‘, ‘+‘, ‘-‘, ‘ב, ‘÷‘ };
int[] rules = new int[256];
String express = show.getText().toString();
express += ‘#‘;
rules[op[0]] = 0;
rules[op[1]] = rules[op[2]] = 1;
rules[op[3]] = rules[op[4]] = 2;
operator.push(‘#‘);
int i = 0, len = express.length();
double value1 = 0, value2 = 0;
double value = 0;
boolean isNum = false;
boolean firstNum = false;
boolean isOver = false;
boolean isZero = false;
boolean isXiao = false;
double index = 1;
String ans = "";
while (i < len) {
char ch = express.charAt(i);
if ((ch >= ‘0‘ && ch <= ‘9‘) || ch == ‘.‘) {
if (ch == ‘.‘)
isXiao = true;
else {
if (isXiao == true) {
index *= 0.1;
value2 = value2 + index * (ch - ‘0‘);
} else
value1 = value1 * 10 + ch - ‘0‘;
}
System.out.println("c = " + ch);
System.out.print("value1 = " + value1);
System.out.println(" value2 = " + value2);
isNum = true;
} else if (isNum == true) {
value = value1 + value2;
if (firstNum == true)
value = -value;
num.push(value);
value1 = value2 = 0;
index = 1;
isXiao = firstNum = isNum = false;
while (rules[ch] <= rules[operator.peek()]) {
char c = operator.pop();
if (c == ‘#‘) {
isOver = true;
break;
}
double num2 = num.pop();
double num1 = num.pop();
if (c == ‘÷‘ && num2 == 0) {
isZero = true;
break;
}
double v = calcu(num1, c, num2);
num.push(v);
}
if (isOver == true || isZero == true)
break;
operator.push(ch);
} else
firstNum = true;
i++;
}
if (isZero == true)
ans = "表达式不成立（出现了除数为0的情况）";
else
ans = num.pop() + "";
show.setText(express.substring(0, express.length() - 1) + " = "
+ ans);
}
private double calcu(double num1, char ch, double num2) {
double ans = 0.0;
switch (ch) {
case ‘+‘:
ans = num1 + num2;
break;
case ‘-‘:
ans = num1 - num2;
break;
case ‘ב:
ans = num1 * num2;
break;
case ‘÷‘:
ans = num1 / num2;
break;
default:
break;
}
return ans;
}
}
android之计算器
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原文地址：http://www.cnblogs.com/huaixiaohai2015/p/5918043.html
