Fragment写主页

MainActivity：

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.Window;
import android.widget.FrameLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    //UI Object
//    private TextView txt_topbar;
    private TextView txt_channel;
    private TextView txt_message;
    private TextView txt_better;
    private TextView txt_setting;
    private FrameLayout ly_content;

    //Fragment Object
    private MyFragment fg1, fg2, fg3;
    private MyFragmentSetting fgSetting;
    private android.app.FragmentManager fManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        fManager = getFragmentManager();
        bindViews();
        txt_channel.performClick();   //模拟一次点击，既进去后选择第一项

    }

    //UI组件初始化与事件绑定
    private void bindViews() {
//        txt_topbar = (TextView) findViewById(R.id.txt_topbar);
        txt_channel = (TextView) findViewById(R.id.txt_channel);
        txt_message = (TextView) findViewById(R.id.txt_message);
        txt_better = (TextView) findViewById(R.id.txt_better);
        txt_setting = (TextView) findViewById(R.id.txt_setting);
        ly_content = (FrameLayout) findViewById(R.id.ly_content);

        txt_channel.setOnClickListener(this);
        txt_message.setOnClickListener(this);
        txt_better.setOnClickListener(this);
        txt_setting.setOnClickListener(this);
    }

    //重置所有文本的选中状态
    private void setSelected() {
        txt_channel.setSelected(false);
        txt_message.setSelected(false);
        txt_better.setSelected(false);
        txt_setting.setSelected(false);
    }

    //隐藏所有Fragment
    private void hideAllFragment(android.app.FragmentTransaction fragmentTransaction) {
        if (fg1 != null) fragmentTransaction.hide(fg1);
        if (fg2 != null) fragmentTransaction.hide(fg2);
        if (fg3 != null) fragmentTransaction.hide(fg3);
        if (fgSetting != null) fragmentTransaction.hide(fgSetting);
    }

    @Override
    public void onClick(View v) {
        FragmentTransaction fTransaction = fManager.beginTransaction();
        hideAllFragment(fTransaction);
        switch (v.getId()) {
            case R.id.txt_channel:
                setSelected();
                txt_channel.setSelected(true);
                if (fg1 == null) {
                    fg1 = new MyFragment("第一个Fragment");
                    fTransaction.add(R.id.ly_content, fg1);
                } else {
                    fTransaction.show(fg1);
                }
                break;
            case R.id.txt_message:
                setSelected();
                txt_message.setSelected(true);
                if (fg2 == null) {
                    fg2 = new MyFragment("第二个Fragment");
                    fTransaction.add(R.id.ly_content, fg2);
                } else {
                    fTransaction.show(fg2);
                }
                break;
            case R.id.txt_better:
                setSelected();
                txt_better.setSelected(true);
                if (fg3 == null) {
                    fg3 = new MyFragment("第三个Fragment");
                    fTransaction.add(R.id.ly_content, fg3);
                } else {
                    fTransaction.show(fg3);
                }
                break;
            case R.id.txt_setting:
                setSelected();
                txt_setting.setSelected(true);
                if (fgSetting == null) {
                    fgSetting = new MyFragmentSetting();
                    fTransaction.add(R.id.ly_content, fgSetting);
                } else {
                    fTransaction.show(fgSetting);
                }
                break;
        }
        fTransaction.commit();
    }
}

MyFragment（前三个页面用的一个Fragment）：

public class MyFragment extends Fragment {

    private String content;
    public MyFragment(String content) {
        this.content = content;
    }

    public MyFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fg_content,container,false);
        TextView txt_content = (TextView) view.findViewById(R.id.txt_content);
        txt_content.setText(content);
        return view;
    }
}

MyFragmentSetting（第四个Fragment是单独的）：

public class MyFragmentSetting extends MyFragment {

    public MyFragmentSetting () {
    }

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

}
布局文件activity_main：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".MainActivity">

    <LinearLayout
        android:id="@+id/ly_tab_bar"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:layout_alignParentBottom="true"
        android:background="@color/bg_white"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/txt_channel"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/tab_menu_bg"
            android:drawablePadding="3dp"
            android:drawableTop="@drawable/tab_menu_channel"
            android:gravity="center"
            android:padding="5dp"
            android:text="@string/tab_menu_alert"
            android:textColor="@drawable/tab_menu_text"
            android:textSize="16sp" />

        <TextView
            android:id="@+id/txt_message"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/tab_menu_bg"
            android:drawablePadding="3dp"
            android:drawableTop="@drawable/tab_menu_message"
            android:gravity="center"
            android:padding="5dp"
            android:text="@string/tab_menu_profile"
            android:textColor="@drawable/tab_menu_text"
            android:textSize="16sp" />

        <TextView
            android:id="@+id/txt_better"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/tab_menu_bg"
            android:drawablePadding="3dp"
            android:drawableTop="@drawable/tab_menu_better"
            android:gravity="center"
            android:padding="5dp"
            android:text="@string/tab_menu_pay"
            android:textColor="@drawable/tab_menu_text"
            android:textSize="16sp" />

        <TextView
            android:id="@+id/txt_setting"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/tab_menu_bg"
            android:drawablePadding="3dp"
            android:drawableTop="@drawable/tab_menu_setting"
            android:gravity="center"
            android:padding="5dp"
            android:text="@string/tab_menu_setting"
            android:textColor="@drawable/tab_menu_text"
            android:textSize="16sp"/>

    </LinearLayout>

    <View
        android:id="@+id/div_tab_bar"
        android:layout_width="match_parent"
        android:layout_height="2px"
        android:background="@color/colorWhite"
        android:layout_above="@id/ly_tab_bar"/>


    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/div_tab_bar"
        android:id="@+id/ly_content">

    </FrameLayout>

</RelativeLayout>
布局文件（fg_content(前三个fragment的布局文件)）：<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/bg_white">

    <TextView
        android:id="@+id/txt_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:text="123"
        android:textColor="@color/text_yellow"
        android:textSize="20sp"/>

</LinearLayout>

布局文件（fg_content(第四个fragment的布局文件)）：<?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="@color/bg_white"
    android:orientation="vertical">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


</LinearLayout>

布局文件（fg_content(前三个fragment的布局文件)）：