Fragment仿qq界面

概述

翻译：碎片
优点：适用于不同的屏幕尺寸和分辨率的UI布局，提高了代码的重用率。

创建

1.通过xml文件

— 1.创建main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:orientation="vertical" >    <fragment        android:id="@+id/center_fragment"        android:name="com.example.fragmenttest.FragmentCenter"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="5" >    </fragment>    <fragment        android:id="@+id/bottom_fragment"        android:name="com.example.fragmenttest.FragmentBottom"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1" >    </fragment></LinearLayout>

— 2.定义两个fragment类

public class FragmentCenter extends Fragment{    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,            Bundle savedInstanceState) {        // TODO Auto-generated method stub        View view = inflater.inflate(R.layout.center_fragment, container, false);        return view;    }}

public class FragmentBottom extends Fragment{    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,            Bundle savedInstanceState) {        // TODO Auto-generated method stub        View view = inflater.inflate(R.layout.bottom_fragment, container,false);        return view;    }}

注意：这里的两个布局文件R.layout.center_fragment和R.layout.bottom_fragment是自定义的普通的布局文件

— 3.MainActivity

public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }}

2.通过java代码动态创建

@SuppressLint("NewApi") public class FragmentTest2Activity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_fragment_test2);        //获取碎片管理器        FragmentManager fragmentManager = getFragmentManager();        //碎片的显示需要使用FragmentTransaction类操作        FragmentTransaction transaction = fragmentManager.beginTransaction();         //获取屏幕管理器和默认的显示        Display display = getWindowManager().getDefaultDisplay();         if(display.getWidth() > display.getHeight()){  //判断横屏            FragmentCenter fragmentCenter = new FragmentCenter(); //获取java类            transaction.replace(android.R.id.content, fragmentCenter);        }else {            FragmentBottom fragmentBottom = new FragmentBottom();            transaction.replace(android.R.id.content, fragmentBottom);        }        transaction.commit();   //使用FragmentTransaction必须要commit    }}

fragment仿qq界面（fragment的切换）

MainActivity中的相关代码

功能：

— 1、创建fragment

— 2、点击相应的按钮时，会切换不同的fragment（在切换的过程中，首先需要判断该fragment是隐藏了还是没有创建过；如果是隐藏了就直接show，如果没有创建过就new，最后调用fragmentTransaction.commit();进行切换）

public class MainActivity extends Activity implements View.OnClickListener {    private ImageView contactImage;    private ImageView msgImage;    private ImageView trendImage;    private ImageView title_head;    private TextView title_center;    private Button title_button;    private ContactFragment contactFragment;    private MsgFragment msgFragment;    private TrendFragment trendFragment;    private FragmentManager fragmentManager;    private FragmentTransaction fragmentTransaction;    //表示是哪个Fragment    int fragment_tag = 0; //默认是消息    static final int FRAGMENT_TAB_MSG = 0;    static final int FRAGMENT_TAB_CONTACT = 1;    static final int FRAGMENT_TAB_PLUGIN = 2;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        setContentView(R.layout.activity_main);        initViews();        fragmentManager = getFragmentManager();        // 第一次启动时选中第0个tab        setTabSelection(0);    }    private void initViews() {        //消息        contactImage = (ImageView) findViewById(R.id.tab_contact);        //联系人        msgImage = (ImageView) findViewById(R.id.tab_conversation);        //动态        trendImage = (ImageView) findViewById(R.id.tab_plugin);        //标题栏        title_head = (ImageView) findViewById(R.id.title_head);        title_center = (TextView) findViewById(R.id.title_center);        title_button = (Button) findViewById(R.id.title_button);        contactImage.setOnClickListener(this);        msgImage.setOnClickListener(this);        trendImage.setOnClickListener(this);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.tab_conversation:                // 当点击了消息tab时，选中第1个tab                setTabSelection(0);                break;            case R.id.tab_contact:                // 当点击了联系人tab时，选中第2个tab                setTabSelection(1);                break;            case R.id.tab_plugin:                // 当点击了动态tab时，选中第3个tab                setTabSelection(2);                break;            default:                break;        }    }    /**     * 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表示消息，1表示联系人，2表示动态     */    private void setTabSelection(int index) {        // 开启一个Fragment事务        fragmentTransaction = fragmentManager.beginTransaction();        // 先隐藏掉所有的Fragment，以防止有多个Fragment显示在界面上的情况        hideFragments(fragmentTransaction);        /*--------------------------------------------------         *      改变底层栏（bottom panel）         *      改变标题栏         *-------------------------------------------------*/        switch (index) {            case 0:  // 当点击了消息tab时，改变控件的图片和文字颜色                //“消息”                                msgImage.setImageResource(R.drawable.skin_tab_icon_conversation_selected);                //normal                contactImage.setImageResource(R.drawable.skin_tab_icon_contact_normal);trendImage.setImageResource(R.drawable.skin_tab_icon_plugin_normal);                //标记为“消息”的fragment                fragment_tag = FRAGMENT_TAB_MSG;                break;            case 1:                //联系人contactImage.setImageResource(R.drawable.skin_tab_icon_contact_selected);                //消息和动态 normal                msgImage.setImageResource(R.drawable.skin_tab_icon_conversation_normal);trendImage.setImageResource(R.drawable.skin_tab_icon_plugin_normal);                //标记为“联系人”的fragment                fragment_tag = FRAGMENT_TAB_CONTACT;                break;            case 2:                //动态                trendImage.setImageResource(R.drawable.skin_tab_icon_plugin_selected);                //normal                contactImage.setImageResource(R.drawable.skin_tab_icon_contact_normal);                msgImage.setImageResource(R.drawable.skin_tab_icon_conversation_normal);                fragment_tag = FRAGMENT_TAB_PLUGIN;   //标记为“动态”的fragment                break;        }        //切换fragment        switchFragment(fragment_tag);    }    private void switchFragment(int tag) {        /*--------------------------------------------------         *          Fragment不存在则新建         *-------------------------------------------------*/        Fragment fragment = null;        if (tag == FRAGMENT_TAB_MSG) {            //不存在则新建            if (msgFragment == null) {                msgFragment = new MsgFragment();            }            fragment = msgFragment;        } else if (tag == FRAGMENT_TAB_CONTACT) {            if (contactFragment == null) {                contactFragment = new ContactFragment();            }            fragment = contactFragment;        } else if (tag == FRAGMENT_TAB_PLUGIN) {            if (trendFragment == null) {                trendFragment = new TrendFragment();            }            fragment = trendFragment;        }        /*--------------------------------------------------         *          显示或者绑定Fragment         *    1.如果隐藏，则显示         *    2.如果第一次使用，add         *-------------------------------------------------*/        if (fragment != null) {            if (fragment.isHidden()) {                fragmentTransaction.show(fragment);            } else if (!fragment.isAdded()) {                fragmentTransaction.add(R.id.content, fragment, tag + "");            }        }        //不为空，切换        if (fragmentTransaction != null && !fragmentTransaction.isEmpty()) {            fragmentTransaction.commit();        }    }    /**     * 将所有的Fragment都置为隐藏状态。     *     * @param transaction 用于对Fragment执行操作的事务     */    private void hideFragments(FragmentTransaction transaction) {        if (contactFragment != null) {            transaction.hide(contactFragment);        }        if (msgFragment != null) {            transaction.hide(msgFragment);        }        if (trendFragment != null) {            transaction.hide(trendFragment);        }    }}

fragment中的相关代码与Activity中的代码类似（要注意有的地方需要用到getActivity（）获得context）