页面适配器项目实例

1、PageListActivity.java

package com.example.myhomework;


import android.content.Context;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.viewpager.widget.PagerAdapter;

import java.util.List;

public class PageListActivity {
    public static class PageListAdapter extends PagerAdapter {
        private final Context context;
        private final List<View> viewList;

        public PageListAdapter(Context context, List<View> viewList) {
            this.context = context;
            this.viewList = viewList;
        }

        @Override
        public int getCount() {
            return viewList.size();
        }

        @Override
        public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
            return view == object;
        }

        @NonNull
        @Override
        public Object instantiateItem(@NonNull ViewGroup container, int position) {
            /*if(container == null){
                container = (ViewGroup) View.inflate(context,R.layout.layout_page,null);
                viewHolder = new ViewHolder();
                viewHolder.page1 = container.findViewById(R.id.page1);
                container.setTag(viewHolder);
            }else{
                viewHolder = (ViewHolder) container.getTag();
            }
            viewHolder.page1.setText((CharSequence) page1.get(position));*/

            /*ViewGroup viewGroup = (ViewGroup) page.get(position).getParent();
            if (viewGroup != null)
                viewGroup.removeView(page.get(position));
            container.addView(page.get(position));
            return container;*/

            container.addView(viewList.get(position));
            return viewList.get(position);
        }

        @Override
        public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
            container.removeView((View) object);
        }
    }
}

2、MainActivity.java

package com.example.myhomework;

import android.content.Context;
import android.os.Bundle;
import android.view.View;

import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private final Context context = MainActivity.this;
    private ViewPager page1;

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

        List<View> viewList = new ArrayList<>();

//        for(int i = 0; i < 10; i++){
//            page1.add();
//        }

        for (int i = 0; i < 6; i++) {
            viewList.add(View.inflate(context, R.layout.layout_page, null));
        }

        PageListActivity.PageListAdapter adapter = new PageListActivity.PageListAdapter(context,viewList);
        page1 = findViewById(R.id.pager);
        page1.setAdapter(adapter);

    }
}

3、activity_main.xml

<?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="vertical"
    tools:ignore="HardcodedText">

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:ignore="MissingConstraints" />

</LinearLayout>

4、layout_page.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">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="猪老三"
        android:gravity="center"
        android:textColor="#159138"
        android:textSize="30sp"
        tools:ignore="MissingConstraints" />

</LinearLayout >

5、成果：可以左右滑动的6个界面

界面.jpg