android.widget.BaseAdapter#registerDataSetObserver ( )源码实例Demo

/**
 * 设置适配器
 * @param adapter
 */
public void setAdapter(BaseAdapter adapter) throws NumberOverFlowException {
	this.adapter = adapter;
	if (adapter.getCount() > MAX_NUM) {
		throw new NumberOverFlowException(adapter.getCount());
	}
	adapter.registerDataSetObserver(new DataSetObserver() {
		@Override
		public void onChanged() {
			super.onChanged();
			onDataSetChanged();
		}

		@Override
		public void onInvalidated() {
			super.onInvalidated();
			onDataSetChanged();
		}
	});
	initChild();
}
 

public ArticleCollectionPagerAdapter(Application app, BaseAdapter data, ToBlob toBlob, FragmentManager fm) {
    super(fm);
    this.app = app;
    this.data = data;
    this.count = data.getCount();
    this.observer = new DataSetObserver(){
        @Override
        public void onChanged() {
            count = ArticleCollectionPagerAdapter.this.data.getCount();
            notifyDataSetChanged();
        }
    };
    data.registerDataSetObserver(observer);
    this.toBlob = toBlob;
}