android-fragment

left_fragment.xml

<?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">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:text="Button"/>

</LinearLayout>

right_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:background="#00ff00"
              android:layout_width="match_parent"
              android:layout_height="match_parent">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:textSize="20sp"
            android:text="This is right fragment"/>
</LinearLayout>

建立LeftFragment 继承Fragment v4包
重写onCreateView方法

View view = inflater.inflate(R.layout.left_fragment, container , false);

RightFragment 同理

修改activity_main
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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="horizontal"
    tools:context="com.example.fragmenttest.MainActivity">

    <fragment
        android:id="@+id/left_fragment"
        android:name="com.example.fragmenttest.LeftFragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"/>

    <fragment
        android:id="@+id/right_fragment"
        android:name="com.example.fragmenttest.RightFragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"/>
</LinearLayout>

动态添加碎片

// 建立的Fragment
replaceFragment(new RightFragment());

private void replaceFragment(Fragment fragment) {
    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    // 第一个参数在主布局替换的位置 fragment
    transaction.replace(R.id.right_layout, fragment);
    transaction.commit();
}

在碎片中模拟返回栈

fragmentTransaction.addToBackStack(null);

活动跟碎片通信

LeftFragment fragment = (LeftFragment) getFragmentManager().findFragmentById(R.id.left_fragment);

碎片跟活动通信

MainActivity activity = (MainActivity) getActivity();

碎片跟碎片通信

MainActivity activity = (MainActivity) getActivity();
LeftFragment fragment = (LeftFragment) activity.getFragmentManager().findFragmentById(R.id.left_fragment);

使用限定符

常用的限定符

使用最小宽度限定符

在res目录下新建layout-sw600dp 大于600dp 会执行目录下的布局