一切都运转正常，但现在我没有得到正在发生的事情，我在listView中显示了10个项目，它的工作正常，直到第6个项目，之后又从第1个项目再次重复??
public class GroupDetailsAdapter extends BaseAdapter {
List<GetSetGroupDetails> group_details = new ArrayList<GetSetGroupDetails>();
Context context;
Typeface face;
public GroupDetailsAdapter(List<GetSetGroupDetails> group_details,
Context context) {
super();
this.group_details.clear();
this.group_details = group_details;
this.context = context;
face = Typeface.createFromAsset(context.getAssets(),
"HelveticaNeueLTStd-Th.otf");
}
@Override
public int getCount() {
// TODO Auto-generated method stub
int count = group_details.size();
return count;
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
@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
View v = convertView;
ViewHolder holder;
if (v == null) {
try {
LayoutInflater vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.group_item, null);
holder = new ViewHolder();
holder.tv_group_name = (TextView) v
.findViewById(R.id.tv_group_name);
String group_name = group_details.get(position).getGroup_name();
holder.tv_group_name.setText(group_name);
holder.tv_group_name.setTypeface(face);
holder.tv_group_reg_id = (TextView) v
.findViewById(R.id.tv_group_reg_id);
String groupRegId = group_details.get(position)
.getGroup_reg_id();
holder.tv_group_reg_id.setText(groupRegId);
holder.tv_group_reg_id.setTypeface(face);
holder.tv_subscriber_count = (TextView) v
.findViewById(R.id.tv_subscriber_count);
holder.tv_subscriber_count.setText(group_details.get(position)
.getSubscriber_count());
v.setTag(holder);
} catch (Exception e) {
e.printStackTrace();
}
} else
holder = (ViewHolder) v.getTag();
return v;
}
class ViewHolder {
TextView tv_group_name;
TextView tv_group_reg_id;
TextView tv_subscriber_count;
}
}
答案 0 :(得分：19)
您正面临数据重复问题，因为您没有遵循实施View-Holder模式的确切标准。
如果view为null，那么你正在执行findViewById（）和设置数据，因此对于第一组项目它将正常运行，后面它将显示下一组项目的相同数据。
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View v = convertView;
ViewHolder holder;
if (v == null) {
try {
LayoutInflater vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.group_item, null);
holder = new ViewHolder();
holder.tv_group_name = (TextView) v
.findViewById(R.id.tv_group_name);
String group_name = group_details.get(position).getGroup_name();
holder.tv_group_name.setText(group_name);
holder.tv_group_name.setTypeface(face);
holder.tv_group_reg_id = (TextView) v
.findViewById(R.id.tv_group_reg_id);
String groupRegId = group_details.get(position)
.getGroup_reg_id();
holder.tv_group_reg_id.setText(groupRegId);
holder.tv_group_reg_id.setTypeface(face);
holder.tv_subscriber_count = (TextView) v
.findViewById(R.id.tv_subscriber_count);
holder.tv_subscriber_count.setText(group_details.get(position)
.getSubscriber_count());
v.setTag(holder);
} catch (Exception e) {
e.printStackTrace();
}
} else
holder = (ViewHolder) v.getTag();
return v;
}
实现View Holder模式的正确方法是在当前视图为空（这将是第一次发生）时查找视图，并仅在执行后设置数据。因此，最终findViewById()进程将首次完成，下次将通过使用附加标记获取视图。
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View v = convertView;
ViewHolder holder;
if (v == null) {
LayoutInflater vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.group_item, null);
holder = new ViewHolder();
holder.tv_group_name = (TextView) v
.findViewById(R.id.tv_group_name);
holder.tv_group_reg_id = (TextView) v
.findViewById(R.id.tv_group_reg_id);
holder.tv_subscriber_count = (TextView) v
.findViewById(R.id.tv_subscriber_count);
v.setTag(holder);
} catch (Exception e) {
e.printStackTrace();
}
} else
holder = (ViewHolder) v.getTag();
String group_name = group_details.get(position).getGroup_name();
holder.tv_group_name.setText(group_name);
holder.tv_group_name.setTypeface(face);
String groupRegId = group_details.get(position)
.getGroup_reg_id();
holder.tv_group_reg_id.setText(groupRegId);
holder.tv_group_reg_id.setTypeface(face);
holder.tv_subscriber_count.setText(group_details.get(position)
.getSubscriber_count());
return v;
}
答案 1 :(得分：-1)
public View getView(int position, View convertView, ViewGroup parent) {
final ViewHolder vh;
View v = convertView;
if(v == null){
v = LayoutInflater.from(ctx).inflate(R.layout.simple_list_item, parent, false);
vh = new ViewHolder(v);
v.setTag(vh);
}
else{
vh = (ViewHolder) v.getTag();
}
vh.tvTitle.setText(list.get(position).toString());
return v;
}
class ViewHolder{
TextView tvTitle;
public ViewHolder(View v){
tvTitle = (TextView) v.findViewById(R.id.tvVideoName);
}