ViewPager

红太狼 2021-01-07 04:32 333阅读 0赞

之前我也写过ViewPager的用法(现在忘干净了)，复习一遍：  
布局activity\_main.xml：

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout 
        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=".MainActivity">
    
        <android.support.v4.view.ViewPager
            android:id="@+id/myViewPager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:overScrollMode="never"/>
    
    </android.support.constraint.ConstraintLayout>

list\_view\_pager.xml：

<?xml version="1.0" encoding="utf-8"?>
    <android.support.constraint.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
        android:layout_height="match_parent">
    
        <ImageView
            android:id="@+id/itemImageView"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    
    </android.support.constraint.ConstraintLayout>

MainActivity：

package com.fitsoft;
    
    import android.graphics.Color;
    import android.os.Bundle;
    import android.support.annotation.NonNull;
    import android.support.v4.view.PagerAdapter;
    import android.support.v4.view.ViewPager;
    import android.support.v7.app.AppCompatActivity;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.ImageView;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class MainActivity extends AppCompatActivity {
    
        ViewPager viewPager;
    
        List<View> list = new ArrayList<>();
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            viewPager  = findViewById(R.id.myViewPager);
    
            //添加四个View(颜色不一样)
            {
                View view = LayoutInflater.from(this).inflate(R.layout.list_view_pager, null);
                ImageView imageView = view.findViewById(R.id.itemImageView);
                imageView.setBackgroundColor(Color.RED);
                list.add(view);
            }
    
            {
                View view = LayoutInflater.from(this).inflate(R.layout.list_view_pager, null);
                ImageView imageView = view.findViewById(R.id.itemImageView);
                imageView.setBackgroundColor(Color.GREEN);
                list.add(view);
            }
    
            {
                View view = LayoutInflater.from(this).inflate(R.layout.list_view_pager, null);
                ImageView imageView = view.findViewById(R.id.itemImageView);
                imageView.setBackgroundColor(Color.BLUE);
                list.add(view);
            }
    
            {
                View view = LayoutInflater.from(this).inflate(R.layout.list_view_pager, null);
                ImageView imageView = view.findViewById(R.id.itemImageView);
                imageView.setBackgroundColor(Color.BLACK);
                list.add(view);
            }
    
            //设置适配器
            viewPager.setAdapter(new PagerAdapter() {
                @Override
                public int getCount() {
                    return list.size();
                }
    
                @Override
                public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
                    return view == o;
                }
    
                //初始化方法
                @NonNull
                @Override
                public Object instantiateItem(@NonNull ViewGroup container, int position) {
                    container.addView(list.get(position));
                    return list.get(position);
                }
    
                //销毁方法
                @Override
                public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
                    container.removeView(list.get(position));
                }
            });
    
    
        }
    
    }

之前写过，不过多介绍，注意ViewPager是在v4包里的。  
效果图：

![1.gif][]

[1.gif]: /images/1609993960961.gif