我正在使用以下代码作为Android中ListView的Cusotm数组适配器
在视图中新建MyAsyncTask(url,callback);将一次又一次地运行,我该怎么做,这样对服务器的查询将只执行一次。
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
final Question question = quesions.get(position);
final OpenionUser myUser = question.getUser();
View view = convertView;
ViewHolder viewHolder = new ViewHolder();
if (convertView == null)
{
view = inflator.inflate(R.layout.question_adapter_layout, parent, false);
viewHolder.firstPhotoPercent = (TextView) view.findViewById(R.id.firstPhotoProgressText);
viewHolder.secondPhotoPercent = (TextView) view.findViewById(R.id.secondPhotoProgressText);
viewHolder.comments = (LinearLayout) view.findViewById(R.id.commentsListView);
viewHolder.profilePic = (ImageButton) view.findViewById(R.id.profile);
viewHolder.leftPic = (ImageButton) view.findViewById(R.id.photo1);
viewHolder.rightPic = (ImageButton) view.findViewById(R.id.photo2);
viewHolder.firstPhotoBg = (RelativeLayout) view.findViewById(R.id.firstPhotoProgress);
viewHolder.secondPhotoBg = (RelativeLayout) view.findViewById(R.id.secondPhotoProgress);
view.setTag(viewHolder);
}
else
viewHolder = (ViewHolder) view.getTag();
// //imageLoader.displayImage(myUser.getProfilePicture(), viewHolder.profilePic, options);
//
viewHolder.username.setText(myUser.getUserName());
viewHolder.question.setText(question.getQuestion());
imageLoader.displayImage(question.getRightThumbnailLink(), viewHolder.rightPic, options);
imageLoader.displayImage(question.getLeftThumbnailLink(), viewHolder.leftPic, options);
String url = String.format(Constants.GET_QUESTION_COMMENTS,
question.getId(),
0,
2);
ResponseCallback callback = new ResponseCallback()
{
@Override
public void onSuccess(HttpResponse response)
{
try {
JSONObject obj = new JSONObject(Utilities.convertStreamToString(response.getEntity().getContent()));
JSONArray array = obj.getJSONArray("comments");
ArrayList<Comment> comments = new ArrayList<Comment>();
for (int i = 0; i < array.length(); i ++)
{
Comment comment = Utilities.getCommentFromJSON(array.getJSONObject(i));
comments.add(comment);
}
addFeaturedViews(comments, viewHolder.comments);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onFailure(HttpResponse exception)
{
}
};
new MyAsyncTask(url, callback);
最佳答案
您可以尝试以下方法:
if(position==0)
{
new MyAsyncTask(url, callback);
}
*在下面的评论中看到Dhanesh Budhrani提供的信息后修改答案*
如果要运行新的MyAsyncTask(url,callback);只有一次,您可以尝试以下操作:
if(firsttime)
{
firsttime = false;
new MyAsyncTask(url, callback);
}
这里firsttime是在适配器的构造函数中初始化为true的布尔变量。