多Fragment的布局使用

╰半夏微凉° 2022-09-06 01:14 153阅读 0赞

直接上效果，一个Activity，三个按钮，三个Fragment，一个按钮对应一个Fragment

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpY2h1YW5wYg_size_16_color_FFFFFF_t_70][] ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpY2h1YW5wYg_size_16_color_FFFFFF_t_70 1][]

1 布局文件

垂直布局，

上面为一个LinearLayout，占1份高度，包含三个按钮，平均分布。

下面为一个FrameLayout，占20份高度，用于显示具体的Fragment。

<?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"
        android:orientation="vertical"
        tools:context=".MainActivity">
    
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
    
            <Button
                android:id="@+id/button1"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="fragment1" />
            <Button
                android:id="@+id/button2"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="fragment2" />
            <Button
                android:id="@+id/button3"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="fragment3" />
        </LinearLayout>
    
        <FrameLayout
            android:id="@+id/mainFm"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="20">
        </FrameLayout>
    </LinearLayout>

2 做三个BlackFragment布局文件，产生对应的类

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NpY2h1YW5wYg_size_16_color_FFFFFF_t_70 2][]

一个Fragment就包含一个简单的TextView

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout 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=".BlankFragment1">
    
        
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="sichuanwww1111" />
    
    </FrameLayout>

3 对应的类文件

package com.example.myfragment;
    
    import android.os.Bundle;
    
    import androidx.fragment.app.Fragment;
    
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    
    /**
     * A simple {@link Fragment} subclass.
     * Use the {@link BlankFragment1#newInstance} factory method to
     * create an instance of this fragment.
     */
    public class BlankFragment1 extends Fragment {
    
        // TODO: Rename parameter arguments, choose names that match
        // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
        private static final String ARG_PARAM1 = "param1";
        private static final String ARG_PARAM2 = "param2";
    
        // TODO: Rename and change types of parameters
        private String mParam1;
        private String mParam2;
    
        public BlankFragment1() {
            // Required empty public constructor
        }
    
        /**
         * Use this factory method to create a new instance of
         * this fragment using the provided parameters.
         *
         * @param param1 Parameter 1.
         * @param param2 Parameter 2.
         * @return A new instance of fragment BlankFragment1.
         */
        // TODO: Rename and change types and number of parameters
        public static BlankFragment1 newInstance(String param1, String param2) {
            BlankFragment1 fragment = new BlankFragment1();
            Bundle args = new Bundle();
            args.putString(ARG_PARAM1, param1);
            args.putString(ARG_PARAM2, param2);
            fragment.setArguments(args);
            return fragment;
        }
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            if (getArguments() != null) {
                mParam1 = getArguments().getString(ARG_PARAM1);
                mParam2 = getArguments().getString(ARG_PARAM2);
            }
        }
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            getActivity().setTitle("Fragment11111");
            return inflater.inflate(R.layout.fragment_blank1, container, false);
        }
    }

4 主界面类代码

package com.example.myfragment;
    
    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;
    import android.widget.FrameLayout;
    
    public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    
        //控件变量
        private FrameLayout mMainFM;
        private Button mButton1;
        private Button mButton2;
        private Button mButton3;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            //用户函数
            initView();
            initFragment();
        }
    
        //自定义函数
        private void replaceFragment(int layout, Fragment fragment)
        {
            FragmentManager manager=getSupportFragmentManager();
            FragmentTransaction fragmentTransaction=manager.beginTransaction();
            fragmentTransaction.replace(layout,fragment);
            fragmentTransaction.addToBackStack(null);
            fragmentTransaction.commit();
        }
        //初始设置fragment
        private void initFragment()
        {
            getSupportFragmentManager()
                    .beginTransaction()
                    .replace(R.id.mainFm,new BlankFragment1())
                    .commit();
        }
    
        //获取必要的控件值
        private void initView()
        {
            mMainFM=(FrameLayout)findViewById(R.id.mainFm);
            mButton1=(Button)findViewById(R.id.button1);
            mButton2=(Button)findViewById(R.id.button2);
            mButton3=(Button)findViewById(R.id.button3);
    
            mButton1.setOnClickListener(this);
            mButton2.setOnClickListener(this);
            mButton3.setOnClickListener(this);
        }
    
        //事件响应函数
        @Override
        public void onClick(View v)
        {
            switch (v.getId())
            {
                case R.id.button1:
                    replaceFragment(R.id.mainFm,new BlankFragment1());
                    break;
                case R.id.button2:
                    replaceFragment(R.id.mainFm,new BlankFragment2());
                    break;
                case R.id.button3:
                    replaceFragment(R.id.mainFm,new BlankFragment3());
                    break;
    
            }
        }
        //end of class
    }

主要代码解析

4.1 类和接口

extends需要创建一个AppCompatActivity的子类

implements 需要使用View.OnClickListener接口

public class MainActivity extends AppCompatActivity
                              implements View.OnClickListener {

4.2 获取必要的控件值

//获取必要的控件值
    private void initView()
    {
        mMainFM=(FrameLayout)findViewById(R.id.mainFm);  //帧控件值
        mButton1=(Button)findViewById(R.id.button1);
        mButton2=(Button)findViewById(R.id.button2);
        mButton3=(Button)findViewById(R.id.button3);
    
        //设置监听事件
        mButton1.setOnClickListener(this);
        mButton2.setOnClickListener(this);
        mButton3.setOnClickListener(this);
    }

4.3 切换不同的FragMent

//自定义函数
    private void replaceFragment(int layout, Fragment fragment)
    {
        FragmentManager manager=getSupportFragmentManager();
        FragmentTransaction fragmentTransaction=manager.beginTransaction();
        fragmentTransaction.replace(layout,fragment);
        fragmentTransaction.addToBackStack(null);
        fragmentTransaction.commit();
    }
    //初始设置fragment
    private void initFragment()
    {
        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.mainFm,new BlankFragment1())
                .commit();
    }

4.4 重载事件响应函数

//事件响应函数
    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
            case R.id.button1:
                replaceFragment(R.id.mainFm,new BlankFragment1());
                break;
            case R.id.button2:
                replaceFragment(R.id.mainFm,new BlankFragment2());
                break;
            case R.id.button3:
                replaceFragment(R.id.mainFm,new BlankFragment3());
                break;
    
        }
    }

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