android开发中ListView与Adapter使用要点介绍

public View getView(int position, View convertView, ViewGroup parent) {
// A ViewHolder keeps references to children views to avoid unneccessary calls
// to findViewById() on each row.
ViewHolder holder;
// When convertView is not null, we can reuse it directly, there is no need
// to reinflate it. We only inflate a new View when the convertView supplied
// by ListView is null.
if (cOnvertView== null) {
cOnvertView= mInflater.inflate(R.layout.list_item_icon_text, null);
Log.v("tag", "positon " + position + " convertView is null, " + "new: " + convertView);
// Creates a ViewHolder and store references to the two children views
// we want to bind data to.
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.text);
holder.icon = (ImageView) convertView.findViewById(R.id.icon);
convertView.setTag(holder);
} else {
// Get the ViewHolder back to get fast access to the TextView
// and the ImageView.
holder = (ViewHolder) convertView.getTag();
Log.v("tag", "positon " + position + " convertView is not null, " + convertView);
}
// Bind the data efficiently with the holder.
holder.text.setText(DATA[position]);
holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2);
return convertView;
}

static class ViewHolder {
TextView text;
ImageView icon;
}

getView() {
switch (getItemViewType(position)) {
case type1:
if(cOnvertView== null) {
} else {
}
break;
case type2:
default:
if(cOnvertView== null) {
} else {
}
break;
}
return convertView;
}
getItemViewType(int position) {
// 根据场景，一般有：
// 1. 不同的item type对应的position是固定的，那么ListView的data可以分别存放
// 2. 不同的item type对应的position是不固定的，那么可以把ListView的data统一放在List中，
// 然后使用instanceof来判断Object的类型进而区分position对应的view type.
}