自定义adapter

自定义Adapter

首先新建一个类MyAdapter继承BaseAdapter

完成构造函数，传入当前的context对象和要显示的数据源

public MyAdapter(Context context, List<ChatMessage> datas) {
inflater = LayoutInflater.from(context);
this.mDatas = datas;
}

完成如下

   //listVIew中将要显示的条目数

       @Override
public int getCount() {
// TODO Auto-generated method stub
return mDatas.size();
}

//获得第几个位置的数据
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return mDatas.get(position);
}

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

//得到要显示的listView中不同类型条目的类型
@Override
public int getItemViewType(int position) {
// TODO Auto-generated method stub
ChatMessage chatMessage = (ChatMessage) getItem(position);
if (chatMessage.getType() == Type.FROMMSG) {
return 0;
} else {
return 1;
}
}

//得到listView中所有要显示条目类型总数
@Override
public int getViewTypeCount() {
// TODO Auto-generated method stub
return 2;
}

//下面是最终要的方法，获得当前条目的View

@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
ChatMessage chatMessage = (ChatMessage) getItem(position);
if (convertView == null) {
if (getItemViewType(position) == 1) {
convertView = inflater.inflate(R.layout.tomsg, parent, false);
viewHolder = new ViewHolder();
viewHolder.msg = (TextView) convertView
.findViewById(R.id.tv_msgsend_msg);
viewHolder.time = (TextView) convertView
.findViewById(R.id.tv_msgsend_time);
} else {
convertView = inflater.inflate(R.layout.frommsg, parent, false);
viewHolder = new ViewHolder();
viewHolder.msg = (TextView) convertView
.findViewById(R.id.tv_msgreceive_msg);
viewHolder.time = (TextView) convertView
.findViewById(R.id.tv_msgreceive_time);
}
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}

//设置数据
viewHolder.msg.setText(chatMessage.getMsg());
viewHolder.time.setText(chatMessage.getTime());

return convertView;
}


class ViewHolder {
TextView time;
TextView msg;
}

这样就完成了自定义Adapter的编写

在显示数据时，新建一个MyAdapter对象将数据源传入

再调用listView.setAdapter(adapter);完成显示数据的功能