Android自定义图片轮播Banner控件使用解析

 <com.xiaomai.bannerview.BannerView    android:id="@+id/bannerView"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    app:aspectRatio="1.5"    app:defaultSrc="@mipmap/ic_launcher"    app:indicatorBackground="@color/white"    app:indicatorHeight="50dp"    app:indicatorPositionSize="8dp"    app:updateTime="3000" />

<resources>  <declare-styleable name="BannerView">    <attr name="aspectRatio" format="float" />  <!-- 宽高比 -->    <attr name="defaultSrc" format="integer|reference" />   <!-- 占位图 -->    <attr name="updateTime" format="integer" />   <!-- 图片切换时间 -->    <attr name="indicatorVisible" format="boolean" /> <!-- 是否显示指示器 -->    <attr name="indicatorHeight" format="dimension" /> <!-- 指示器的高度 -->    <attr name="indicatorBackground" format="color|reference" />  <!-- 指示器的背景颜色 -->    <attr name="indicatorPositionSize" format="dimension" /> <!-- 指示点的大小 -->  </declare-styleable></resources>

public class BannerView extends RelativeLayout {  public BannerView(Context context) {    this(context, null);  }  public BannerView(Context context, AttributeSet attrs) {    this(context, attrs, 0);  }  public BannerView(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);}

private Context context;  private Handler handler;  private ImageLoader imageLoader;  private DisplayImageOptions options;  private boolean isHaveHandler = true;// 当用户点击轮播图时，取消handler队列，也就是取消滚动  // 控件Start  private ViewPager viewPager;  private LinearLayout indicator;// 指示器  private onItemClickListener listener;  // 控件End  // 自定义属性Start  private float mAspectRatio; // 宽高比  private int defaultImageResource; // 默认占位图  private int updateTime; // 图片切换的时间间隔,默认3秒  private boolean showIndicator; // 是否显示指示器,默认显示  private int indicatorHeight;// 指示器的高度,默认35dp  private int indicatorPositionSize; // 指示器的大小  private int indicatorBackground; // 指示器的背景颜色  // 自定义属性End  // 数据Start  private int imageCount;  private int lastPosition;  private List<Integer> imageResources;  private List<Image> imageUrls;  // 数据End

public BannerView(Context context, AttributeSet attrs, int defStyleAttr) {    super(context, attrs, defStyleAttr);    parseCustomAttributes(context, attrs);    this.context = context;    handler = new Handler();    imageLoader = ImageLoader.getInstance();    options = HSApplication.getDisplayOptions().build();    initViews();  }  /**   * 解析自定义属性   *   * @param context   * @param attrs   */  private void parseCustomAttributes(Context context, AttributeSet attrs) {    TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.BannerView);    mAspectRatio = typedArray.getFloat(R.styleable.BannerView_aspectRatio, 0f);    defaultImageResource = typedArray.getResourceId(R.styleable.BannerView_defaultSrc,        R.drawable.about_us);    updateTime = typedArray.getInt(R.styleable.BannerView_updateTime, 3000);    showIndicator = typedArray.getBoolean(R.styleable.BannerView_indicatorVisible, true);    indicatorHeight = (int) (typedArray.getDimension(R.styleable.BannerView_indicatorHeight,        Utils.dip2px(context, 35)));    indicatorBackground = typedArray.getResourceId(R.styleable.BannerView_indicatorBackground,        R.color.white_alpha00);    indicatorPositionSize = (int) typedArray.getDimension(        R.styleable.BannerView_indicatorPositionSize, Utils.dip2px(context, 5));    typedArray.recycle();  }  private void initViews() {    viewPager = new ViewPager(context);    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {      @Override      public void onPageScrolled(int position, float positionOffset,          int positionOffsetPixels) {      }      @Override      public void onPageSelected(int position) {        if (showIndicator) {          for (int i = 0; i < indicator.getChildCount(); i++) {            indicator.getChildAt(i).setSelected(false);          }          indicator.getChildAt(position % imageCount).setSelected(true);        }        lastPosition = position;      }      @Override      public void onPageScrollStateChanged(int state) {        switch (state) {          case ViewPager.SCROLL_STATE_IDLE:// 空闲状态            if (!isHaveHandler) {              isHaveHandler = true;              handler.postDelayed(updateRunnable, updateTime);            }            break;          case ViewPager.SCROLL_STATE_DRAGGING:// 用户滑动状态            handler.removeCallbacks(updateRunnable);            isHaveHandler = false;            break;        }      }    });    addView(viewPager, new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,        ViewGroup.LayoutParams.WRAP_CONTENT));    if (showIndicator) {      indicator = new LinearLayout(context);      indicator.setOrientation(LinearLayout.HORIZONTAL);      indicator.setGravity(Gravity.CENTER);      indicator.setBackgroundResource(indicatorBackground);      RelativeLayout.LayoutParams layoutParams = new LayoutParams(          ViewGroup.LayoutParams.MATCH_PARENT, indicatorHeight);      layoutParams.addRule(ALIGN_PARENT_BOTTOM);      addView(indicator, layoutParams);    }}

 public void setImageResources(List<Integer> imageResources) {    if (imageResources == null || imageResources.size() == 0) {      throw new RuntimeException("图片资源为空");    }    this.imageResources = imageResources;    imageCount = imageResources.size();  }  public void setImageUrls(List<Image> imageUrls) {    if (imageUrls == null || imageUrls.size() == 0) {      throw new RuntimeException("图片地址资源为空");    }    this.imageUrls = imageUrls;    imageCount = imageUrls.size();    loadImages();  }  private void loadImages() {    if (showIndicator) {      addIndicationPoint();    }    viewPager.setAdapter(new MyViewPageAdapter());    viewPager.setCurrentItem(200 - (200 % imageCount));    handler.removeCallbacks(updateRunnable);    handler.postDelayed(updateRunnable, updateTime);  }  /**   * 添加指示点到指示器中   */  private void addIndicationPoint() {    // 防止刷新重复添加    if (indicator.getChildCount() > 0) {      indicator.removeAllViews();    }    View pointView;    int margin = Utils.dip2px(context, 5f);    LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(        indicatorPositionSize, indicatorPositionSize);    layoutParams.setMargins(margin, margin, margin, margin);    for (int i = 0; i < imageCount; i++) {      pointView = new View(context);      pointView.setBackgroundResource(R.drawable.indicator_selector);      if (i == lastPosition) {        pointView.setSelected(true);      } else {        pointView.setSelected(false);      }      indicator.addView(pointView, layoutParams);    }  }  private class MyViewPageAdapter extends PagerAdapter {    @Override    public int getCount() {      return Integer.MAX_VALUE;    }    @Override    public boolean isViewFromObject(View view, Object object) {      return view == object;    }    @Override    public Object instantiateItem(ViewGroup container, final int position) {      final ImageView imageView = new ImageView(container.getContext());      imageView.setImageResource(defaultImageResource);      imageView.setScaleType(ImageView.ScaleType.FIT_XY);      final Image image = imageUrls.get(position % imageCount);      imageLoader.displayImage(image.getImageUrl(), imageView, options);      imageView.setOnClickListener(new OnClickListener() {        @Override        public void onClick(View v) {          if (listener != null) {            listener.onClick(v, position % imageCount, image.getAction(),                image.getUrl());          }        }      });      container.addView(imageView);      return imageView;    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {      container.removeView((View) object);    }  }  private Runnable updateRunnable = new Runnable() {    @Override    public void run() {      viewPager.setCurrentItem(lastPosition + 1);      handler.postDelayed(updateRunnable, updateTime);    }/**   * 点击监听回调事件   */  public interface onItemClickListener {    void onClick(View view, int position, String action, String url);  }  public void setOnItemClickListener(onItemClickListener listener) {    this.listener = listener;  }