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;
}