viewpager图片轮播

转载:https://www.cnblogs.com/luhuan/p/8047098.html
与启动页不同

• 适配器需要改动返回值,取最大(无限)
• 适配器和activity取位置要除以图片size取余数最为位置(无限)
• 使用另一种方法添加小圆点(代码中添加),而不是xml静态设置
• 设置了一个handle作为滑动(自动)
  修改完代码如下`

我是在fragement中创造的,可能和activity中有点不同

public class HomeFragment extends Fragment implements View.OnClickListener {

    //图片轮播
    LinearLayout linearLayoutDots;
    private ViewPager mViewPager;
    private ImageView iv;
    private TextView mTvPagerTitle;
    private List<ImageView> mImageList;//轮播的图片集合
    private String[] mImageTitles;//标题集合
    private int previousPosition = 0;//前一个被选中的position
    private List<View> mDots;//小点
    private boolean isStop = false;//线程是否停止
    // 在values文件假下创建了pager_image_ids.xml文件，并定义了4张轮播图对应的id，用于点击事件
    private int[] imgae_ids = new int[]{R.id.carousel1,R.id.carousel2,R.id.carousel3,R.id.carousel4};
    private  View view;

    public HomeFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_home, container, false)
        mViewPager = (ViewPager) view.findViewById(R.id.viewPager);
        mTvPagerTitle = (TextView) view.findViewById(R.id.tv_pager_title);
        linearLayoutDots = (LinearLayout) view.findViewById(R.id.lineLayout_dot);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        initView();
        initAction();
        initData();
        initViewPager();
        //autoPlayView();//开启线程，自动播放
        handler.sendEmptyMessageDelayed(0,2000);
    }



    /**
     * 控件初始化
     */
    protected void initView() {

    }

    /**
     * 事件监听
     */
    protected void initAction() {
    }

    /**
     * 数据处理
     */
    protected void initData() {

        //初始化标题列表和图片
        mImageTitles = new String[]{"这是一个好看的标题1","这是一个优美的标题2","这是一个快乐的标题3","这是一个开心的标题4"};
        int[] imageRess = new int[]{R.drawable.carousel1,R.drawable.carousel2,R.drawable.carousel3,R.drawable.carousel4};
        //添加图片到图片列表里
        mImageList = new ArrayList<>();
        for (int i = 0; i < imageRess.length; i++) {
            iv = new ImageView(getActivity());
            iv.setBackgroundResource(imageRess[i]);//设置图片
            iv.setId(imgae_ids[i]);//顺便给图片设置id
            iv.setOnClickListener(this);//设置图片点击事件
            mImageList.add(iv);
        }
        //添加轮播点
        mDots = addDots(linearLayoutDots,fromResToDrawable(getActivity(),R.drawable.selector_dots),mImageList.size());//其中fromResToDrawable()方法是我自定义的，目的是将资源文件转成Drawable
    }

    /**
     *  给PagerViw设置适配器，并实现自动轮播功能
     */
    private void initViewPager() {
        CircleViewPagerAdapter viewPagerAdapter = new CircleViewPagerAdapter(mImageList, mViewPager);
        mViewPager.setAdapter(viewPagerAdapter);
        mViewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                //伪无限循环，滑到最后一张图片又从新进入第一张图片
                int newPosition = position % mImageList.size();
                // 把当前选中的点给切换了, 还有描述信息也切换
                mTvPagerTitle.setText(mImageTitles[newPosition]);//图片下面设置显示文本
                //设置轮播点
                LinearLayout.LayoutParams newDotParams = (LinearLayout.LayoutParams) mDots.get(newPosition).getLayoutParams();
                newDotParams.width = 24;
                newDotParams.height = 24;
               mDots.get(newPosition).setLayoutParams(newDotParams);
               mDots.get(newPosition).setBackground(fromResToDrawable(getActivity(),R.drawable.dot_true));
                LinearLayout.LayoutParams oldDotParams = (LinearLayout.LayoutParams) mDots.get(previousPosition).getLayoutParams();
                oldDotParams.width = 16;
                oldDotParams.height = 16;
               mDots.get(previousPosition).setLayoutParams(oldDotParams);
                mDots.get(previousPosition).setBackground(fromResToDrawable(getActivity(),R.drawable.dot_false));
                // 把当前的索引赋值给前一个索引变量, 方便下一次再切换.
                previousPosition = newPosition;
            }
            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
        setFirstLocation();
    }

    /**
     * 设置刚打开app时显示的图片和文字
     */
    private void setFirstLocation() {
        mTvPagerTitle.setText(mImageTitles[previousPosition]);
        // 把ViewPager设置为默认选中Integer.MAX_VALUE / t2，从十几亿次开始轮播图片，达到无限循环目的;
        int m = (Integer.MAX_VALUE / 2) % mImageList.size();
        int currentPosition = Integer.MAX_VALUE / 2 - m;
        mViewPager.setCurrentItem(currentPosition);

       LinearLayout.LayoutParams newDotParams = (LinearLayout.LayoutParams) mDots.get(0).getLayoutParams();
        newDotParams.width = 24;
        newDotParams.height = 24;
        mDots.get(0).setLayoutParams(newDotParams);
        mDots.get(0).setBackground(fromResToDrawable(getActivity(),R.drawable.dot_true));
    }

    /**
     * 设置自动播放,每隔PAGER_TIOME秒换一张图片
     */
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

            int item = mViewPager.getCurrentItem() +1;
            mViewPager.setCurrentItem(item);
            handler.sendEmptyMessageDelayed(0,2000);
        }
    };

    /**
     * 资源图片转Drawable
     * @param context
     * @param resId
     * @return
     */
    public Drawable fromResToDrawable(Context context, int resId) {
        return context.getResources().getDrawable(resId);
    }

    /**
     * 动态添加一个点
     * @param linearLayout 添加到LinearLayout布局
     * @param backgount 设置
     * @return
     */
    public int addDot(final LinearLayout linearLayout, Drawable backgount) {
        final View dot = new View(getActivity());
        LinearLayout.LayoutParams dotParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);
        dotParams.width = 16;
        dotParams.height = 16;
        dotParams.setMargins(8,0,8,0);
        dot.setLayoutParams(dotParams);
        dot.setBackground(fromResToDrawable(getActivity(),R.drawable.dot_false));
        //dot.setClickable(false);
        dot.setId(View.generateViewId());
        linearLayout.addView(dot);
        return dot.getId();
    }

    /**
     * 添加多个轮播小点到横向线性布局
     * @param linearLayout
     * @param backgount
     * @param number
     * @return
     */
    public List<View> addDots(final LinearLayout linearLayout, Drawable backgount, int number){
        List<View> dots = new ArrayList<>();
        for (int i = 0; i < number; i++) {
            int dotId = addDot(linearLayout,backgount);
            dots.add(view.findViewById(dotId));
        }
        return dots;
    }


    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.carousel1:
                Toast.makeText(getActivity(), "图片1被点击", Toast.LENGTH_SHORT).show();
                break;
            case R.id.carousel2:
                Toast.makeText(getActivity(), "图片2被点击", Toast.LENGTH_SHORT).show();
                break;
            case R.id.carousel3:
                Toast.makeText(getActivity(), "图片3被点击", Toast.LENGTH_SHORT).show();
                break;
            case R.id.carousel4:
                Toast.makeText(getActivity(), "图片4被点击", Toast.LENGTH_SHORT).show();
                break;
        }
    }


}

xml文件

<FrameLayout
            android:layout_width="match_parent"
            android:layout_height="200dp"
            android:layout_marginTop="5dp">

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

            <LinearLayout
                android:background="#33000000"
                android:orientation="horizontal"
                android:layout_gravity="bottom"
                android:gravity="center_vertical"
                android:layout_width="match_parent"
                android:layout_height="35dip">
                <TextView
                    android:layout_weight="8"
                    android:id="@+id/tv_pager_title"
                    android:text="标题"
                    android:paddingLeft="8dip"
                    android:gravity="center_vertical"
                    android:textColor="@color/white"
                    android:layout_width="0dp"
                    android:layout_height="match_parent"/>
                <!--用来动态添加轮播小点-->
                <LinearLayout
                    android:id="@+id/lineLayout_dot"
                    android:layout_weight="2"
                    android:gravity="center|right"
                    android:layout_marginRight="5dp"
                    android:paddingLeft="3dp"
                    android:paddingRight="3dp"
                    android:orientation="horizontal"
                    android:layout_width="0dp"
                    android:layout_height="match_parent">
                </LinearLayout>

            </LinearLayout>
        </FrameLayout>