仿大众点评android源码

【实例截图】

【核心代码】

package com.jhd.fangdazhongdianping.ui;

import com.jhd.fangdazhongdianping.R;
import com.jhd.fangdazhongdianping.R.layout;
import com.jhd.fangdazhongdianping.R.menu;
import com.jhd.fangdazhongdianping.ui.fragment.HomeFragment;
import com.jhd.fangdazhongdianping.ui.fragment.MyFragment;
import com.jhd.fangdazhongdianping.ui.fragment.SearchFragment;
import com.jhd.fangdazhongdianping.ui.fragment.TuanFragment;
import com.lidroid.xutils.ViewUtils;
import com.lidroid.xutils.view.annotation.ViewInject;

import android.os.Bundle;
import android.app.Activity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.Menu;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.Toast;

public class MainActivity extends FragmentActivity implements OnCheckedChangeListener{

@ViewInject(R.id.main_bottom_tabs)
private RadioGroup group;
@ViewInject(R.id.main_home)
private RadioButton main_home;
private FragmentManager fragmentManager;//管理fragment
private HomeFragment home;
private MyFragment my;
private SearchFragment search;
private TuanFragment tuan;
private long exitTime=0;//两次按返回退出

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewUtils.inject(this);
//初始化fragmentManager
fragmentManager=getSupportFragmentManager();
//设置默认选中
main_home.setChecked(true);
group.setOnCheckedChangeListener(this);
//切换不同的fragment
changeFragment(0);

}

@Override
public 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;
}

@Override
public void onCheckedChanged(RadioGroup arg0, int checkedId) {
switch (checkedId) {
case R.id.main_home:
changeFragment(0);
break;
case R.id.main_tuan:
changeFragment(1);
break;
case R.id.main_search:
changeFragment(2);
break;
case R.id.main_my:
changeFragment(3);
break;
default:
break;
}
}
//切换不同的fragment
/** 
     * 根据传入的index参数来设置选中的tab页。 
     *  
     * @param index 
     *            每个tab页对应的下标。0表示home，1表示tuan，2表示search，3表示my。 
     */  
public void changeFragment(int index)//同时保存每个fragment
{
FragmentTransaction beginTransaction = fragmentManager.beginTransaction();
hideFragments(beginTransaction);
switch (index) {
case 0:
if(home==null){
home=new HomeFragment();
beginTransaction.add(R.id.main_content, home);
}else{
beginTransaction.show(home);
}
break;
case 1:
if(tuan==null){
tuan=new TuanFragment();
beginTransaction.add(R.id.main_content, tuan);
}else{
beginTransaction.show(tuan);
}
break;
case 2:
if(search==null){
search=new SearchFragment();
beginTransaction.add(R.id.main_content, search);
}else{
beginTransaction.show(search);
}
break;
case 3:
if(my==null){
my=new MyFragment();
beginTransaction.add(R.id.main_content, my);
}else{
beginTransaction.show(my);
}
break;

default:
break;
}
beginTransaction.commit();//需要提交事务
}
private void hideFragments(FragmentTransaction transaction) {  
if (home != null)   
transaction.hide(home);           
if (my != null)   
transaction.hide(my);            
if (tuan != null)   
transaction.hide(tuan);            
if (search != null)   
transaction.hide(search);           
}  

@Override
public void onBackPressed() {    


exit();  ///退出应用

}

public void exit() {   //退出应用
        if ((System.currentTimeMillis() - exitTime) > 2000) {
            Toast.makeText(getApplicationContext(), "再按一次退出程序",
                    Toast.LENGTH_SHORT).show();
            exitTime = System.currentTimeMillis();
        } else {
            finish();
            //System.exit(0);
        }
    }
@Override
public void finish() {
// TODO Auto-generated method stub
super.finish();
// this.overridePendingTransition(0,R.anim.activity_close);
}

}