【No8.】ViewHolder的再次简化、优化写法 Cool！

package com.example.simpleviewholder;

import android.util.SparseArray;
import android.view.View;

/**
 * Viewholder的简化
 * 
 * @ClassName: ViewHolder
 * @Description: TODO
 * @author Simon
 * @date 2014-8-22 上午9:56:29
 */
@SuppressWarnings("unchecked")
public class ViewHolder {
	public static <T extends View> T get(View view, int id) {
		SparseArray<View> viewHolder = (SparseArray<View>) view.getTag();
		if (viewHolder == null) {
			viewHolder = new SparseArray<View>();
			view.setTag(viewHolder);
		}
		View childView = viewHolder.get(id);
		if (childView == null) {
			childView = view.findViewById(id);
			viewHolder.put(id, childView);
		}
		return (T) childView;
	}
}

以上是ViewHolder的优化写法、可以直接作为一个工具类放到Utils包里面；

对于SparseArray类的介绍我就不多说了大家直接看吧：http://blog.youkuaiyun.com/kaixinbingju/article/details/8658428

下面是用法：

public class MyAdapter extends BaseAdapter {
		private LayoutInflater mInflater;
		private List<String> list;

		MyAdapter(Context mContext,List<String> list) {
			mInflater = LayoutInflater.from(mContext);
			this.list = list;
		}

		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return list != null ? list.size() : 0;
		}

		@Override
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return list.get(position);
		}

		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
			if (convertView == null) {
				Log.i("Simon", "convertView == null" + (convertView == null));
				convertView = mInflater.inflate(R.layout.item, parent, false);
			}

			TextView mTextView = ViewHolder.get(convertView, R.id.textView1);
			mTextView.setText(list.get(position).trim());

			return convertView;
		}

	}

是不是瞬间感觉自己的代码 高大上 了~