安卓点击左右切换页面Fragement

package cn.wuxiaocheng.fragment;

import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.Window;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class MainActivity extends Activity implements OnClickListener{

    private FragmentManager fm;
    private FragmentTransaction ft;
    
    //两个页面
    private FragmentHome fh;
    private FragmentSet fs;
    
    //两个底部
    private TextView tvhome;
    private TextView tvset;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);        //去掉顶部标题栏
        setContentView(R.layout.activity_main);
            
        //初始化底部
        initView();
        //设置默认的Fragment
        setDefaultFragment();
    }

    //设置默认的Fragment
    private void setDefaultFragment() {
        fm = getFragmentManager();
        ft = fm.beginTransaction();
        fh = new FragmentHome();
        ft.replace(R.id.main_view, fh);
        ft.commit();
    }

    //初始化空间和声明事件
    private void initView() {
        tvhome = (TextView) findViewById(R.id.id_home);
        tvset = (TextView) findViewById(R.id.id_set);
        
        tvhome.setOnClickListener(this);
        tvset.setOnClickListener(this);
    }

    //点击事件
    @Override
    public void onClick(View v) {
        fm = getFragmentManager();
        //开启fragment事物
        ft = fm.beginTransaction();
        
        switch (v.getId()) {
        case R.id.id_home:
            if (fh == null) {
                fh = new FragmentHome();
            }
            ft.replace(R.id.main_view, fh);
            break;
        case R.id.id_set:
            if (fs == null) {
                fs = new FragmentSet();
            }
            ft.replace(R.id.main_view, fs);
            break;
        }
        // ft.addToBackStack(); 
        //事物提交
        ft.commit();
    }
}

package cn.wuxiaocheng.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FragmentHome extends Fragment{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_home,null);
        
        return view;
    }
}

package cn.wuxiaocheng.fragment;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FragmentSet extends Fragment{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_set,null);
        
        return view;
    }
}

<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:orientation="vertical" >
    
    <FrameLayout 
            android:id="@+id/main_view"
            android:layout_height="0dp"
            android:layout_width="match_parent"
            android:layout_weight="1"></FrameLayout>
    
    <LinearLayout 
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:orientation="horizontal"
        android:background="#eeeeee"
        >
        
        <TextView
            android:id="@+id/id_home"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="首页" />
        <TextView
            android:id="@+id/id_set"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:gravity="center"
            android:text="设置" />        
        </LinearLayout>

</LinearLayout>

<?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:gravity="center" >
    
    <TextView
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:textSize="26sp"
        android:text="Home"/>

</LinearLayout>

<?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:background="#00FF66"
    android:gravity="center" >
    
    <TextView
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:textColor="#FF0033"
        android:textSize="26sp"
        android:text="Set"/>

</LinearLayout>