android简单计算器.docx

欢迎大家补充package com.example.zzz;/此文使用了fragment的模块。/此文使用了fragment的模块。/此文使用了fragment的模块。/此文使用了fragment的模块。import android.support.v7.app.ActionBarActivity;import android.support.v7.app.ActionBar;import android.support.v4.app.Fragment;import android.os.Bundle;import android.view.LayoutInflater;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.ViewGroup;import android.widget.Button;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;import android.os.Build;public class MainActivity extends ActionBarActivity Overrideprotected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);if (savedInstanceState = null) getSupportFragmentManager().beginTransaction().add(R.id.container, new PlaceholderFragment().commit();Overridepublic boolean onCreateOptionsMenu(Menu menu) / Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;Overridepublic 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 AndroidM id = item.getItemId();if (id = R.id.action_settings) return true;return super.onOptionsItemSelected(item);/* * A placeholder fragment containing a simple view. */public static class PlaceholderFragment extends Fragment /此文使用了fragment的模块。private double a,b;private int num=0;private Button button1;private Button button2;private Button button3;private Button button4;private Button button5;private Button button6;private Button button7;private Button button8;private Button button9;private Button button0;private Button buttonjia;private Button buttonjian;private Button buttoncheng;private Button buttonchu;private Button buttonxiaoshudian;private Button buttonqingchu;private Button buttondengyu;private TextView text;public PlaceholderFragment() Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) View rootView = inflater.inflate(R.layout.fragment_main, container,false);findbutton(rootView);/定义一个函数用于找组件ViewEvent(rootView);/定义一个函数。用于初始化监听器（将组件与监听器相连接）/注意，设置监听器的时候必须保证找到了组件。否则程序用易出错。特别提醒return rootView;/使用fragment，此处的返回值必须为rootView，上面有函数可以看一下、private void findbutton(View rootView)button0=(Button)rootView.findViewById(R.id.button0);button1=(Button)rootView.findViewById(R.id.button1);button2=(Button)rootView.findViewById(R.id.button2);button3=(Button)rootView.findViewById(R.id.button3);button4=(Button)rootView.findViewById(R.id.button4);button5=(Button)rootView.findViewById(R.id.button5);button6=(Button)rootView.findViewById(R.id.button6);button7=(Button)rootView.findViewById(R.id.button7);button8=(Button)rootView.findViewById(R.id.button8);button9=(Button)rootView.findViewById(R.id.button9);button0=(Button)rootView.findViewById(R.id.button0);buttonjia=(Button)rootView.findViewById(R.id.buttonjia);buttonjian=(Button)rootView.findViewById(R.id.buttonjian);buttoncheng=(Button)rootView.findViewById(R.id.buttoncheng);buttonchu=(Button)rootView.findViewById(R.id.buttonchu);buttonqingchu=(Button)rootView.findViewById(R.id.qingchu);buttondengyu=(Button)rootView.findViewById(R.id.buttondengyu);/text，找到文本编辑框组件，在下面需要传输值。text = (TextView)rootView.findViewById(R.id.editText1);private void ViewEvent(View rootView)button0.setOnClickListener(l);button1.setOnClickListener(l);button2.setOnClickListener(l);button3.setOnClickListener(l);button4.setOnClickListener(l);button5.setOnClickListener(l);button6.setOnClickListener(l);button7.setOnClickListener(l);button8.setOnClickListener(l);button9.setOnClickListener(l);buttonjia.setOnClickListener(l);buttonjian.setOnClickListener(l);buttoncheng.setOnClickListener(l);buttonchu.setOnClickListener(l);buttondengyu.setOnClickListener(l);buttonqingchu.setOnClickListener(l);/实例化监听器：这一步必须的，相当于把监听器给物理化了。 View.OnClickListener l=new View.OnClickListener() Override/监听器实例化后会自动生成此方法，onClick函数中编辑简单计算器的方法。public void onClick(View v) / TODO Auto-generated method stubString s = text.getText().toString();/上面找到了文本编辑框，/接上句。此处为将text中的内容传给s变量Button btn =(Button)v;String g=(String) btn.getText();/获取按钮的值。if(btn.getId()=R.id.button0|btn.getId()=R.id.button1|btn.getId()=R.id.button2|btn.getId()=R.id.button3|btn.getId()=R.id.button4|btn.getId()=R.id.button5|btn.getId()=R.id.button6|btn.getId()=R.id.button7|btn.getId()=R.id.button8|btn.getId()=R.id.button9)/此处含义：若按钮的id等于layout中的id，则text的值等于g（按钮的值）；text.setText(g);return;if(btn.getId()=R.id.buttonjia)a=Double.parseDouble(s);num=1;text.setText();return;if(btn.getId()=R.id.buttonjian)a=Double.parseDouble(s);num=2;text.setText();return;if(btn.getId()=R.id.buttoncheng)a=Double.parseDouble(s);num=3;text.setText();return;if(btn.getId()=R.id.buttonchu)a=Double.parseDouble(s);num=4;text.setText();return;if(btn.getId()=R.id.qingchu) a=0;b=0;num=0;text.setText();return;if(btn.getId()=R.id.buttondengyu) b=Double.parseDouble(s);switch(num)/此处的num纯粹是为了switch存在。因为需要用if语句，所以用/case num 作为+，-，*，/，的执行