android轮播图简单实现（左右无限滑动,自动轮播）

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/ming_ruo_xiao_xi/article/details/77868529

直接上代码了，都有注释，原理很简单

public class MainActivity extends AppCompatActivity {
private static final String Tag = MainActivity.class.getSimpleName();
private ViewPager BannerViegPager;//轮播图Viewpager
private TextView BannerTittle;//轮播图标题
private LinearLayout BannerPointLayout;
private ArrayList<ImageView> mImageViews;
private Handler mHandler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        int item = (BannerViegPager.getCurrentItem() + 1);
        BannerViegPager.setCurrentItem(item);
        mHandler.sendEmptyMessageDelayed(0, 4000);
    }
};

private final int[] imageIds = {
        R.drawable.img1,
        R.drawable.img2,
        R.drawable.img3,
        R.drawable.img4,
};
private final String[] textStrings = {
        "今夏最美",
        "欢度元宵",
        "情人节",
        "花开半夏",
};
/*上次高亮显示的位置*/
private int prePosition = 0;
private boolean isDragging = false;//是否已经滚动

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //ViewPager  使用
    //1在布局中定义ViewPager
    //2在代码中实例化ViewPager
    //3准备数据
    //4设置适配器（pageradapter）-item布局绑定数据
    //图片资源id
    BannerViegPager = (ViewPager) findViewById(R.id.BannerViegPager);
    BannerTittle = (TextView) findViewById(R.id.BannerTittle);
    BannerPointLayout = (LinearLayout) findViewById(R.id.BannerPointLayout);
    mImageViews = new ArrayList<>();
    for (int i = 0; i < imageIds.length; i++) {
        ImageView mImageView = new ImageView(this);
        mImageView.setImageResource(imageIds[i]);
        mImageViews.add(mImageView);
        ImageView point = new ImageView(this);
        point.setBackgroundResource(R.drawable.point_selector);
        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(20, 20);

        if (i == 0) {
            point.setEnabled(true);//显示红色
        } else {
            point.setEnabled(false);//显示灰色
            layoutParams.leftMargin = 20;
        }
        point.setLayoutParams(layoutParams);
        BannerPointLayout.addView(point);
    }
    BannerViegPager.setAdapter(new MyPagerAdapter());
    BannerTittle.setText(textStrings[prePosition]);
    //设置viewpager页面的改变
    BannerViegPager.addOnPageChangeListener(new MyOnPageChangeLister());
    //设置中间位置
    BannerViegPager.setCurrentItem(Integer.MAX_VALUE / 2 - (Integer.MAX_VALUE / 2) % mImageViews.size());
    mHandler.sendEmptyMessageDelayed(0, 3000);
}

class MyOnPageChangeLister implements ViewPager.OnPageChangeListener {
    /**
     * 功能：当页面滚动时回掉这个方法
     *
     * @param position             当前页面位置
     * @param positionOffset       滑动页面的百分比
     * @param positionOffsetPixels 在屏幕上滑动的像数
     */
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    /**
     * 功能：当页面选中停留时回掉这个方法
     *
     * @param position 当前页面位置
     *                 返回值：空
     */
    @Override
    public void onPageSelected(int position) {
        Log.e("textStrings", "position==" + position);
        Log.e("textStrings", "position%" + "%" + imageIds.length + "==" + position % imageIds.length);
        //设置对应页面的文本信息
        BannerTittle.setText(textStrings[position % imageIds.length]);
        //把上一个高亮设置默认灰色
        BannerPointLayout.getChildAt(prePosition).setEnabled(false);
        //把当前设置为高亮红色
        BannerPointLayout.getChildAt(position % imageIds.length).setEnabled(true);
        prePosition = position % imageIds.length;

    }

    /**
     * 功能：当页面滚动状态变化的时候回掉这个方法
     * 静止->滑动
     * 滑动->静止
     * 静止->拖拽
     *
     * @param state 当前页面位置
     *              返回值：空
     */
    @Override
    public void onPageScrollStateChanged(int state) {
       /* SCROLL_STATE_IDLE：空闲状态
        SCROLL_STATE_DRAGGING：滑动状态
        SCROLL_STATE_SETTLING：滑动后自然沉降的状态*/
        if (ViewPager.SCROLL_STATE_DRAGGING == state) {
            isDragging = true;
            mHandler.removeCallbacksAndMessages(null);
            Log.e(Tag, "SCROLL_STATE_DRAGGING-----------");
        } else if (ViewPager.SCROLL_STATE_IDLE == state) {
            Log.e(Tag, "SCROLL_STATE_IDLE-----------");
        } else if (ViewPager.SCROLL_STATE_SETTLING == state && isDragging) {
            isDragging = false;
            mHandler.removeCallbacksAndMessages(null);
            mHandler.sendEmptyMessageDelayed(0, 4000);
            Log.e(Tag, "SCROLL_STATE_SETTLING------------");
        }
    }
}

private class MyPagerAdapter extends PagerAdapter {
    /**
     * 功能：
     *
     * @param container Viewpager自身
     * @param position  当前实例化页面的位置
     */
    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        Log.e(Tag, "instantiateItem" + position);
        ImageView mImageView = mImageViews.get(position % imageIds.length);
        container.addView(mImageView);
        mImageView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                Log.e("motionEvent", "" + motionEvent);
                switch (motionEvent.getAction()) {
                    case MotionEvent.ACTION_DOWN://手指按下
                        Log.e("setOnTouchListener", "手指按下");
                        mHandler.removeCallbacksAndMessages(null);
                        break;
                    case MotionEvent.ACTION_MOVE://手指在这个控件上移动
                        Log.e("setOnTouchListener", "手指移动");
                        break;
             /*       case MotionEvent.ACTION_CANCEL://手指在这个控件上移动
                        Log.e("setOnTouchListener", "ACTION_CANCEL手指移开");
                        mHandler.sendEmptyMessageDelayed(0, 4000);
                        break;*/
                    case MotionEvent.ACTION_UP://手指移开
                        Log.e("setOnTouchListener", "手指移开");
                        mHandler.sendEmptyMessageDelayed(0, 4000);
                        break;
                }
                return false;
            }
        });
        mImageView.setTag(position);
        mImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e(Tag, "点击事件");
                int position = (int) v.getTag() % imageIds.length;
                String text = textStrings[position];
                Toast.makeText(MainActivity.this, "text==" + text, Toast.LENGTH_SHORT).show();

            }
        });
        return mImageView;
    }

    /**
     * 释放资源
     *
     * @param container Viewpager自身
     * @param position  释放的位置
     * @param object    释放的界面
     */
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        //super.destroyItem(container, position, object);
        Log.e(Tag, "destroyItem" + position);
        container.removeView((View) object);

    }

    /**
     * 功能：得到viewPager总数
     * 无参
     * 返回值：空
     */
    @Override
    public int getCount() {
        //return imageViews.size();
        return Integer.MAX_VALUE;//为了设置无限轮滑
    }

    /**
     * 比较View和 object是否同一实例
     *
     * @param view
     * @param object
     * @return
     */
    @Override
    public boolean isViewFromObject(View view, Object object) {
       /* if (view == object) return true;
        else return false;*/
        return view == object;

        }
    }
}

布局文件activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    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="com.lxx.commentdemo.bannerview.MainActivity">

    <android.support.v4.view.ViewPager
        android:id="@+id/BannerViegPager"
        android:layout_width="match_parent"
        android:layout_height="180dp">
    </android.support.v4.view.ViewPager>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#44000000"
        android:padding="5dp"
        android:layout_alignBottom="@id/BannerViegPager"
        android:orientation="vertical">
        <TextView
            android:id="@+id/BannerTittle"
            android:layout_gravity="center_horizontal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="轮播标题"
            />
        <LinearLayout
            android:id="@+id/BannerPointLayout"
            android:layout_width="wrap_content"
            android:layout_gravity="center_horizontal"
            android:orientation="horizontal"
            android:layout_height="wrap_content">
        </LinearLayout>
    </LinearLayout>

</RelativeLayout>

圆形指示器
point_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_enabled="false" android:drawable="@drawable/point_normal"/>
<item android:state_enabled="true" android:drawable="@drawable/point_press"/>
</selector>

point_press.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="oval">
    <size
        android:width="8dp"
        android:height="8dp"/>
    <solid android:color="#ff0000"/>
</shape>

Demo下载