Imageloader, listview.notifyDataSetChanged刷新問題，圖片閃爍

轉載請註明出處：http://blog.csdn.net/harryweasley/article/details/49678739

我在項目中，用了ImageLoader來顯示圖片，這樣引出一個問題，偶爾在我調用notifyDataSetChanged這個方法時候，圖片全部閃爍一下，原因是圖片全部重新加載了一次，導致閃爍。

下面是我之前的getView方法中。下面的ImageLoader直接調用，造成每次notifyDataSetChanged，重新調用了ImageLoader方法。

@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder;
		if (convertView == null) {
			convertView = LayoutInflater.from(context).inflate(R.layout.item_app_wall2, parent, false);
			holder = new ViewHolder();
			holder.icon = (ImageView) convertView.findViewById(R.id.app_icon);
			holder.name = (MarqueeText) convertView.findViewById(R.id.app_name);
			// holder.grade = (ImageView)
			// convertView.findViewById(R.id.grade);
			holder.size = (TextView) convertView.findViewById(R.id.app_size);
			holder.count = (TextView) convertView.findViewById(R.id.app_count);
			holder.ratingBar = (RatingBar) convertView.findViewById(R.id.grade);
			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}

		ImageLoader.getInstance().displayImage(searchAppList.get(position).getHttpIco(), holder.icon,
				DisplayImageOptionUtil.getInstance().getOptions());
		

		holder.name.setText(searchAppList.get(position).getName().trim());
		holder.size.setText(CommonUtil.format(searchAppList.get(position).getApkSize() / (float) 1024) + "M");
		AppStatistics statistics = searchAppList.get(position).getAppStatistics();
		if (statistics != null) {

			holder.count.setText(statistics.getDownloadCount() + "次");
		}
		holder.ratingBar.setRating(searchAppList.get(position).getAveccore() / 2f);

		return convertView;
	}

下面我做出了修改，如果當前圖片是之前的圖片，則不會調用ImageLoader，否則調用ImageLoader。

public View getView(int position, View convertView, ViewGroup parent) {
		ViewHolder holder;
		if (convertView == null) {
			convertView = LayoutInflater.from(context).inflate(R.layout.item_app_wall2, parent, false);
			holder = new ViewHolder();
			holder.icon = (ImageView) convertView.findViewById(R.id.app_icon);
			holder.name = (MarqueeText) convertView.findViewById(R.id.app_name);
			// holder.grade = (ImageView)
			// convertView.findViewById(R.id.grade);
			holder.size = (TextView) convertView.findViewById(R.id.app_size);
			holder.count = (TextView) convertView.findViewById(R.id.app_count);
			holder.ratingBar = (RatingBar) convertView.findViewById(R.id.grade);
			convertView.setTag(holder);
		} else {
			holder = (ViewHolder) convertView.getTag();
		}

		
		if (searchAppList.get(position).getHttpIco().equals(holder.icon.getTag())) {

		} else {
			// 如果不相同，就加載。現在在這裏來改變閃爍的情況
			ImageLoader.getInstance().displayImage(searchAppList.get(position).getHttpIco(), holder.icon,
					DisplayImageOptionUtil.getInstance().getOptions());
			holder.icon.setTag(searchAppList.get(position).getHttpIco());
		}

		holder.name.setText(searchAppList.get(position).getName().trim());
		holder.size.setText(CommonUtil.format(searchAppList.get(position).getApkSize() / (float)1024) + "M");
		AppStatistics statistics = searchAppList.get(position).getAppStatistics();
		if (statistics != null) {

			holder.count.setText(statistics.getDownloadCount() + "次");
		}
		holder.ratingBar.setRating(searchAppList.get(position).getAveccore() / 2f);
		return convertView;
	}

通過ImageView.getTag和setTag方法來，判定當前圖片是否是之前的，如果是之前，則不會刷新圖片，如果不是，再刷新。