android:viewpager最简例子

一，代码:

1,xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.PageActivity">


    <androidx.viewpager.widget.ViewPager
        android:id="@+id/imageViewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


</androidx.constraintlayout.widget.ConstraintLayout>

2,java

GoodsInfo.java

package com.example.okdemo1.model;

public class GoodsInfo {
    private int id;
    //private String name;
    private String pic;

    public GoodsInfo(int id, String pic) {
        this.id = id;
        this.pic = pic;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic;
    }
}

ImagePagerAdapater.java

package com.example.okdemo1.adapter;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;

import androidx.viewpager.widget.PagerAdapter;
import com.bumptech.glide.Glide;
import com.bumptech.glide.load.engine.DiskCacheStrategy;
import com.example.okdemo1.activity.PageActivity;
import com.example.okdemo1.model.GoodsInfo;

import java.util.ArrayList;
import java.util.List;
public class ImagePagerAdapater extends PagerAdapter {
    // 声明一个图像视图列表
    private List<ImageView> mViewList = new ArrayList<ImageView>();
    // 声明一个商品信息列表
    private List<GoodsInfo> mGoodsList = new ArrayList<GoodsInfo>();
    // 图像翻页适配器的构造方法，传入上下文与商品信息列表
    public ImagePagerAdapater(Context context, List<GoodsInfo> goodsList) {
        mGoodsList = goodsList;
        // 给每个商品分配一个专用的图像视图
        for (int i = 0; i < mGoodsList.size(); i++) {
            ImageView view = new ImageView(context); // 创建一个图像视图对象
            view.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
            //view.setImageResource(mGoodsList.get(i).getPic());
            Glide.with(context)
                    .load(mGoodsList.get(i).getPic())
                    //.apply(RequestOptions.circleCropTransform()) // 使用 circleCropTransform() 方法设置圆形图片，也可以使用圆角半径的方法设置圆角
                    .diskCacheStrategy(DiskCacheStrategy.ALL) // 缓存原始图片和转换后的图片到磁盘
                    .skipMemoryCache(false) // 不跳过内存缓存
                    .into(view);
            mViewList.add(view); // 把该商品的图像视图添加到图像视图列表
        }
    }
    // 获取页面项的个数
    public int getCount() {
        return mViewList.size();
    }
    // 判断当前视图是否来自指定对象
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }
    // 从容器中销毁指定位置的页面
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(mViewList.get(position));
    }
    // 实例化指定位置的页面，并将其添加到容器中
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(mViewList.get(position));
        return mViewList.get(position);
    }
    // 获得指定页面的标题文本
    public CharSequence getPageTitle(int position) {
        return String.valueOf(mGoodsList.get(position).getId());
    }
}

PageActivity.java

package com.example.okdemo1.activity;

import android.os.Bundle;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;
import androidx.viewpager.widget.ViewPager;

import com.example.okdemo1.R;
import com.example.okdemo1.model.GoodsInfo;
import com.example.okdemo1.adapter.ImagePagerAdapater;

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

public class PageActivity extends AppCompatActivity {
    private ViewPager viewPager;
    private List<GoodsInfo> mGoodsList; // 手机商品列表

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_page);

        mGoodsList = getDefaultList();
        // 构建一个商品图片的翻页适配器
        ImagePagerAdapater adapter = new ImagePagerAdapater(this, mGoodsList);
        // 从布局视图中获取名叫imageViewPager的翻页视图
        ViewPager vp_content = findViewById(R.id.imageViewPager);
        vp_content.setAdapter(adapter); // 设置翻页视图的适配器
        vp_content.setCurrentItem(0); // 设置翻页视图显示第一页

    }

    private List<GoodsInfo> getDefaultList() {
        List<GoodsInfo> goodsList = new ArrayList<>();

        GoodsInfo g1 = new GoodsInfo(1,"https://wx2.sinaimg.cn/mw690/0034c2ttly1i0s6zuaqrkj635s2n4npe02.jpg");
        goodsList.add(g1);
        GoodsInfo g2 = new GoodsInfo(2,"https://wx4.sinaimg.cn/mw690/0034c2ttly1i0s6zu16kuj62bc3cge8102.jpg");
        goodsList.add(g2);
        GoodsInfo g3 = new GoodsInfo(3,"https://wx2.sinaimg.cn/large/989d17dbly1i0rx07jopej20lo0c6q3s.jpg");
        goodsList.add(g3);
        return goodsList;
    }
}

 

二，测试效果: