目錄

一、創建一個Fragment專案

二、在專案中創建一個左碎片布局

三、創建一個類來控制布局

四、創建另一個右碎片布局

五、創建布局對應的類

六、創建第二個右布局

七、創建對應的類

八、更改主布局

九、在主活動中注冊功能

Fragmen 主要用于平板電腦或手機橫屏

一、創建專案

創建一個新專案專案名為Fragment

二、創建第一個碎片布局

在layout下創建一個布局

右擊 layout / New / Layout Resource File

取名為 left_frag 并使用 LinearLayout 布局

左碎片布局設定成按鈕欄

<?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:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/btn_1"
        android:text="碎片1"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/btn_2"
        android:text="碎片2"/>



</LinearLayout>

三、創建一個類來控制布局

在 java / 右擊 com.example.fragment / New / Java Class

類名取為 LeftFrag

LeftFrag 類中的代碼如下

package com.example.fragment;

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

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class LeftFrag extends Fragment {
    /**
     * Called to have the fragment instantiate its user interface view.
     * This is optional, and non-graphical fragments can return null. This will be called between
     * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}.
     * <p>A default View can be returned by calling  in your
     * constructor. Otherwise, this method returns null.
     *
     * <p>It is recommended to <strong>only</strong> inflate the layout in this method and move
     * logic that operates on the returned View to {@link #onViewCreated(View, Bundle)}.
     *
     * <p>If you return a View from here, you will later be called in
     * {@link #onDestroyView} when the view is being released.
     *
     * @param inflater           The LayoutInflater object that can be used to inflate
     *                           any views in the fragment,
     * @param container          If non-null, this is the parent view that the fragment's
     *                           UI should be attached to.  The fragment should not add the view itself,
     *                           but this can be used to generate the LayoutParams of the view.
     * @param savedInstanceState If non-null, this fragment is being re-constructed
     *                           from a previous saved state as given here.
     * @return Return the View for the fragment's UI, or null.
     */
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater,
                             @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.left_frag,container,false);
        return view;
    }
}

四、創建第一個右布局

同樣的方法創建一個右布局

取名為：righr_frag1

右布局設定成顯示欄

righr_frag1 中的代碼為：

<?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="#ffccff">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:textSize="30sp"
        android:text="第一個碎片內容"/>


</LinearLayout>

五、創建右碎片布局對應的類

同樣的方法創建一個類

取名為：RightFrag1

RightFrag1類中的代碼為：

package com.example.fragment;

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

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class RightFrag1 extends Fragment {
    /**
     * Called to have the fragment instantiate its user interface view.
     * This is optional, and non-graphical fragments can return null. This will be called between
     * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}.
     * <p>A default View can be returned by calling  in your
     * constructor. Otherwise, this method returns null.
     *
     * <p>It is recommended to <strong>only</strong> inflate the layout in this method and move
     * logic that operates on the returned View to {@link #onViewCreated(View, Bundle)}.
     *
     * <p>If you return a View from here, you will later be called in
     * {@link #onDestroyView} when the view is being released.
     *
     * @param inflater           The LayoutInflater object that can be used to inflate
     *                           any views in the fragment,
     * @param container          If non-null, this is the parent view that the fragment's
     *                           UI should be attached to.  The fragment should not add the view itself,
     *                           but this can be used to generate the LayoutParams of the view.
     * @param savedInstanceState If non-null, this fragment is being re-constructed
     *                           from a previous saved state as given here.
     * @return Return the View for the fragment's UI, or null.
     */
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater,
                             @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.right_frag1,container,false);
        return view;
    }
}

六、創建第二個右布局

同樣的方法創建第二個右布局

取名為：

right_frag2

right_frag2 中的代碼為：

<?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="#550099">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:textSize="30sp"
        android:text="第二個碎片內容"/>

</LinearLayout>

七、創建第二個右布局對應的類

同樣的方法

想必你已經猜到它的名稱了

沒錯就是：RightFrag2

RightFrag2 中的代碼為：

package com.example.fragment;

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

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

public class RightFrag2 extends Fragment {
    /**
     * Called to have the fragment instantiate its user interface view.
     * This is optional, and non-graphical fragments can return null. This will be called between
     * {@link #onCreate(Bundle)} and {@link #onActivityCreated(Bundle)}.
     * <p>A default View can be returned by calling  in your
     * constructor. Otherwise, this method returns null.
     *
     * <p>It is recommended to <strong>only</strong> inflate the layout in this method and move
     * logic that operates on the returned View to {@link #onViewCreated(View, Bundle)}.
     *
     * <p>If you return a View from here, you will later be called in
     * {@link #onDestroyView} when the view is being released.
     *
     * @param inflater           The LayoutInflater object that can be used to inflate
     *                           any views in the fragment,
     * @param container          If non-null, this is the parent view that the fragment's
     *                           UI should be attached to.  The fragment should not add the view itself,
     *                           but this can be used to generate the LayoutParams of the view.
     * @param savedInstanceState If non-null, this fragment is being re-constructed
     *                           from a previous saved state as given here.
     * @return Return the View for the fragment's UI, or null.
     */
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater,
                             @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.right_frag2,container,false);
        return view;
    }
}

八、修改主布局

把activity_main 中的代碼改為：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="horizontal">

    //左布局設定為靜態
    <fragment
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:id="@+id/left_layout"
        android:name="com.example.fragment.LeftFrag"/>

    //右布局設定為動態
    <FrameLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="2"
        android:id="@+id/right_layout"/>

</LinearLayout>

九、在主活動中注冊功能

MainActivity 中的代碼為：

package com.example.fragment;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn_1 = (Button) findViewById(R.id.btn_1);
        btn_1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                replaceFragment(new RightFrag1());
            }
        });

        Button btn_2 = (Button) findViewById(R.id.btn_2);
        btn_2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                replaceFragment(new RightFrag2());
            }
        });
    }

    private void replaceFragment(Fragment fragment) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.right_layout,fragment);
        transaction.commit();
    }


}

到這里你對Fragment應該有個印象了試著自己做一個新聞頁面吧

謝謝閱讀，你的關注是我創作的最大動力😘