ViewPager，使用Fragment实现

　　效果如图：

使用Fragment实现tab的缺点就是不能够滑动。不过应该也算优点，具体场景可以自由选择。

完整代码：imooc-tab022fragment，在我的百度云网盘上。

MainAcgtivity.java

 package com.example.imooc_tab02;

 import android.os.Bundle;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentTransaction;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.ImageButton;
 import android.widget.LinearLayout;

 public class MainActivity extends FragmentActivity implements OnClickListener {
     // tabs
     LinearLayout tab_weixin, tab_frd, tab_addr, tab_settings;
     // ImageButton
     ImageButton btn_weixin, btn_py, btn_txl, btn_sz;

     tab01 t1;
     tab02 t2;
     tab03 t3;
     tab04 t4;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         t1 = new tab01();
         t2 = new tab02();
         t3 = new tab03();
         t4 = new tab04();
         initView();
         initEvents();

         /*
          * 把tab添加到FrameLayout中，transaction的前一个参数是FrameLayout
          * 的id,第二个参数是Fragment的继承类的实例对象
          */
         // transaction.add(R.id.id_fragment, t1);

     }

     private void initEvents() {
         tab_weixin.setOnClickListener(this);
         tab_frd.setOnClickListener(this);
         tab_addr.setOnClickListener(this);
         tab_settings.setOnClickListener(this);
         tab_addr.callOnClick();//设置通讯录为默认点击，
     }

     private void initView() {
         // TODO Auto-generated method stub
         tab_weixin = (LinearLayout) findViewById(R.id.id_tab_weixin2);
         // tab_frd,tab_addr,tab_settings
         tab_frd = (LinearLayout) findViewById(R.id.id_tab_frd2);
         tab_addr = (LinearLayout) findViewById(R.id.id_tab_address2);
         tab_settings = (LinearLayout) findViewById(R.id.id_tab_settings2);

         // btn_weixin,btn_py,btn_txl,btn_sz;
         btn_weixin = (ImageButton) findViewById(R.id.id_imgbtn_wx);
         btn_py = (ImageButton) findViewById(R.id.id_imgbtn_py);
         btn_txl = (ImageButton) findViewById(R.id.id_imgbtn_txl);
         btn_sz = (ImageButton) findViewById(R.id.id_imgbtn_sz);
     }

     @Override
     public void onClick(View v) {
         // TODO Auto-generated method stub
         FragmentManager manager = getSupportFragmentManager();
         FragmentTransaction transaction = manager.beginTransaction();
         hideFragment(transaction);
         switch (v.getId()) {
         case R.id.id_tab_weixin2:
             resetImg();
             if(!t1.isAdded()){
                 //如果fragment对象t1没有被添加，那么就添加并显示
                 transaction.add(R.id.id_fragment, t1);
             }
             transaction.show(t1);
             btn_weixin.setImageResource(R.drawable.tab_weixin_pressed);
             break;
         case R.id.id_tab_frd2:
             resetImg();
             if (!t2.isAdded()) {
                 transaction.add(R.id.id_fragment, t2);
             }
             transaction.show(t2);
             btn_py.setImageResource(R.drawable.tab_find_frd_pressed);
             break;
         case R.id.id_tab_address2:
             resetImg();
             if (!t3.isAdded()) {
                 transaction.add(R.id.id_fragment, t3);
             }
             transaction.show(t3);
             btn_txl.setImageResource(R.drawable.tab_address_pressed);
             break;
         case R.id.id_tab_settings2:
             resetImg();
             if (!t4.isAdded()) {
                 transaction.add(R.id.id_fragment, t4);
             }
             transaction.show(t4);
             btn_sz.setImageResource(R.drawable.tab_settings_pressed);
             break;

         default:
             break;
         }
         transaction.commit();
     }

     private void hideFragment(FragmentTransaction transaction) {
         System.out.println("====开始hideFragment()...====");
         // TODO Auto-generated method stub
         if (t1 != null) {
             System.out.println("hide(t1)...");
             transaction.hide(t1);
         }
         if (t2 != null) {
             System.out.println("hide(t2)...");
             transaction.hide(t2);
         }
         if (t3 != null) {
             System.out.println("hide(t3)...");
             transaction.hide(t3);
         }
         if (t4 != null) {
             System.out.println("hide(t4)...");
             transaction.hide(t4);
         }
     }

     // 重置按钮为灰色的
     public void resetImg() {
         btn_weixin.setImageResource(R.drawable.tab_weixin_normal);
         btn_py.setImageResource(R.drawable.tab_find_frd_normal);
         btn_txl.setImageResource(R.drawable.tab_address_normal);
         btn_sz.setImageResource(R.drawable.tab_settings_normal);
     }
 }