< ?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="#FF0000">
    <textview android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Fragment"
        android:textColor="#FFFFFF"></textview>
 
</linearlayout>

package com.yusian.fragment;
 
 
import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
 
/**
 * Created by Sian on 2017/3/18.
 */
 
public class UpFragment extends Fragment {
    @Nullable
    @Override
    // 相当于Activity的setContentView；
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_up, container, false);
    }
}

<?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="vertical"
    android:weightSum="2"
    tools:context="com.yusian.fragment.MainActivity">
 
    <fragment
        android:id="@+id/fg_first"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:name="com.yusian.fragment.UpFragment"/>
 
</LinearLayout>