//效果图：

//java代码部分：

package com.jc.cal;

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;

public class MainActivity extends Activity {

// 定义九个数字private Button one;private Button two;private Button three;private Button four;private Button five;private Button six;private Button seven;private Button eight;private Button nine;private Button zero;

private Button dot;private Button add;private Button sub;private Button mul;private Button div;private Button clear;

private Button equal;private EditText led;

String num1 = "";String num2 = "";double num3 = 0;String result = "";String sign = "+";int mark = 0;boolean flag = true;boolean dotmark = true;

@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);

zero = (Button) findViewById(R.id.zero);one = (Button) findViewById(R.id.one);two = (Button) findViewById(R.id.two);three = (Button) findViewById(R.id.three);four = (Button) findViewById(R.id.four);five = (Button) findViewById(R.id.five);six = (Button) findViewById(R.id.six);seven = (Button) findViewById(R.id.seven);eight = (Button) findViewById(R.id.eight);nine = (Button) findViewById(R.id.nine);add = (Button) findViewById(R.id.add);sub = (Button) findViewById(R.id.sub);mul = (Button) findViewById(R.id.mul);div = (Button) findViewById(R.id.div);clear = (Button) findViewById(R.id.clear);led = (EditText) findViewById(R.id.led);equal = (Button) findViewById(R.id.equal);dot = (Button) findViewById(R.id.dot);

zero.setOnClickListener(new OnClickListener() {public void onClick(View v) {if (mark == 0) {num1 = num1 + "0";led.setText(num1);} else if (mark == 1) {num2 = num2 + "0";led.setText(num1 + sign + num2);} else {