用Fragment实现如新浪微博一样的底部菜单的切换

像我这个有强迫症的人来说，自从TabActivity抛弃之后，再使用看到一个个警告和一条条划着的横线，心里很不舒服，现在终于下定决心用Fragment来替换掉TabActivity了！我的研究成果如下：

首先是MainActivity，它需要继承FragmentActivity(这里是指：版本是3.0之前的继承FragmentActivity，3.0版本之后的继承Activity就可以)，对于FragmentActivity的声明周期我就不过多介绍了，和Activity差不了多少，自己也能弄明白！下边是MainActivity的代码：

package net.loonggg.fragment;import android.os.Bundle;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.Window;import android.widget.RadioButton;import android.widget.RadioGroup;import android.widget.RadioGroup.OnCheckedChangeListener;public class MainActivity extends FragmentActivity {private Fragment[] mFragments;private RadioGroup bottomRg;private FragmentManager fragmentManager;private FragmentTransaction fragmentTransaction;private RadioButton rbOne, rbTwo, rbThree, rbFour;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.activity_main);mFragments = new Fragment[3];fragmentManager = getSupportFragmentManager();mFragments[0] = fragmentManager.findFragmentById(R.id.fragement_main);mFragments[1] = fragmentManager.findFragmentById(R.id.fragement_search);mFragments[2] = fragmentManager.findFragmentById(R.id.fragement_setting);fragmentTransaction = fragmentManager.beginTransaction().hide(mFragments[0]).hide(mFragments[1]).hide(mFragments[2]);fragmentTransaction.show(mFragments[0]).commit();setFragmentIndicator();}private void setFragmentIndicator() {bottomRg = (RadioGroup) findViewById(R.id.bottomRg);rbOne = (RadioButton) findViewById(R.id.rbOne);rbTwo = (RadioButton) findViewById(R.id.rbTwo);rbThree = (RadioButton) findViewById(R.id.rbThree);bottomRg.setOnCheckedChangeListener(new OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {fragmentTransaction = fragmentManager.beginTransaction().hide(mFragments[0]).hide(mFragments[1]).hide(mFragments[2]);switch (checkedId) {case R.id.rbOne:fragmentTransaction.show(mFragments[0]).commit();break;case R.id.rbTwo:fragmentTransaction.show(mFragments[1]).commit();break;case R.id.rbThree:fragmentTransaction.show(mFragments[2]).commit();break;default:break;}}});}}

下边对应的是MainActivity的布局文件activity_main.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@drawable/activity_bg"    android:orientation="vertical" >    <!-- 上边主页面 -->    <fragment        android:id="@+id/fragement_main"        android:name="net.loonggg.fragment.FragmentMain"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:layout_weight="10" />    <fragment        android:id="@+id/fragement_search"        android:name="net.loonggg.fragment.FragmentSearch"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:layout_weight="10" />    <fragment        android:id="@+id/fragement_setting"        android:name="net.loonggg.fragment.FragmentSetting"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:layout_weight="10" />    <!-- 底部菜单页面 -->    <RadioGroup        android:id="@+id/bottomRg"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_weight="0.5"        android:background="@drawable/tab_footer_bg"        android:orientation="horizontal" >        <RadioButton            android:id="@+id/rbOne"            style="@style/rg_btn_style"            android:checked="true"            android:drawableTop="@drawable/rb_one_btn_selector"            android:text="首页" />        <RadioButton            android:id="@+id/rbTwo"            style="@style/rg_btn_style"            android:drawableTop="@drawable/rb_two_btn_selector"            android:text="搜索" />        <RadioButton            android:id="@+id/rbThree"            style="@style/rg_btn_style"            android:drawableTop="@drawable/rb_three_btn_selector"            android:text="设置" />    </RadioGroup></LinearLayout>

这里为了大家方便，展示一下项目的布局图：

再下边是要设计的首页界面，它是继承的Fragment，具体看代码：

package net.loonggg.fragment;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;public class FragmentMain extends Fragment {private TextView tv;@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {return inflater.inflate(R.layout.fragment_main, container, false);}@Overridepublic void onActivityCreated(Bundle savedInstanceState) {super.onActivityCreated(savedInstanceState);tv = (TextView) getView().findViewById(R.id.titleTv);tv.setText("首页");}}

接着是对应的布局文件代码fragment_main.xml：

<?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" >    <include        android:id="@+id/one_title"        layout="@layout/title_bar" />    <TextView        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:gravity="center"        android:text="这是首页"        android:textColor="#000000" /></LinearLayout>

再接着是：搜索界面的代码：

package net.loonggg.fragment;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;public class FragmentSearch extends Fragment {private TextView tv;@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {return inflater.inflate(R.layout.fragment_search, container, false);}@Overridepublic void onActivityCreated(Bundle savedInstanceState) {super.onActivityCreated(savedInstanceState);tv = (TextView) getView().findViewById(R.id.titleTv);tv.setText("搜索");}@Overridepublic void onPause() {super.onPause();}}

如上是对应的布局文件的代码fragment_search.xml：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:orientation="vertical" >    <include layout="@layout/title_bar" />    <TextView        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:gravity="center"        android:text="这是搜索界面"        android:textColor="#000000" /></LinearLayout>

紧跟着是：设置界面的代码：

package net.loonggg.fragment;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;public class FragmentSetting extends Fragment {private TextView tv;@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {return inflater.inflate(R.layout.fragment_setting, container, false);}@Overridepublic void onActivityCreated(Bundle savedInstanceState) {super.onActivityCreated(savedInstanceState);tv = (TextView) getView().findViewById(R.id.titleTv);tv.setText("设置");}}

当然一样，下边对应的是设置界面的布局文件代码fragment_setting.xml：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:orientation="vertical" >    <include layout="@layout/title_bar" />    <TextView        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:gravity="center"        android:text="这是设置页面"        android:textColor="#000000" /></LinearLayout>

最后是我用的title_bar.xml文件，这个文件是嵌入到各个界面中的那个顶部的标题的布局文件，代码如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:background="@drawable/title_bg"    android:gravity="center"    android:orientation="vertical" >    <TextView        android:id="@+id/titleTv"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center"        android:gravity="center"        android:textColor="#ffffff"        android:textSize="20sp" /></LinearLayout>

到这里就基本完成了！！！你会了吗?