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[英]Exception in thread “main” java.lang.IndexOutOfBoundsException: Index: 20, Size: 20
[英]java.lang.IndexOutOfBoundsException: Invalid index 20, size is 20
我正在使用自定义适配器从JSON字符串加载20个项目,并在第4位和第14位实现广告。 我遇到的是,当我滚动查看项目#19时,它崩溃并显示标题错误。
我知道错误是指它正在尝试访问不在数组中的索引,但是我认为这是因为它在索引中包含了adViews(不应该)。 我觉得这很简单,我很想念,但请帮忙。 这是我的2个适配器:
public class ListViewAdapter extends BaseAdapter implements AdListener {
private final Activity activity;
private final BaseAdapter delegate;
public ListViewAdapter(Activity activity, BaseAdapter delegate) {
this.activity = activity;
this.delegate = delegate;
}
@Override
public int getCount() {
// Total count includes list items and ads.
return delegate.getCount() + 2;
}
@Override
public Object getItem(int position) {
// Return null if an item is an ad. Otherwise return the delegate item.
if (isItemAnAd(position)) {
return null;
}
return delegate.getItem(position - 1);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (isItemAnAd(position)) {
if (convertView instanceof AdView) {
return convertView;
} else {
AdView adView = new AdView(activity, AdSize.SMART_BANNER,"AD ID (removed for post)" );
AdRequest adRequest = new AdRequest();
adView.loadAd(adRequest);
return adView;
}
} else {
return delegate.getView(position-1, convertView, parent);
}
}
@Override
public int getViewTypeCount() {
return delegate.getViewTypeCount() + 1;
}
@Override
public int getItemViewType(int position) {
if (isItemAnAd(position)) {
return delegate.getViewTypeCount();
} else {
return delegate.getItemViewType(getOffsetPosition(position));
}
}
@Override
public boolean areAllItemsEnabled() {
return false;
}
@Override
public boolean isEnabled(int position) {
return (!isItemAnAd(position)) && delegate.isEnabled(getOffsetPosition(position));
}
private boolean isItemAnAd(int position) {
// Place an ad at the first and last list view positions.
return (position == 4 || position == 14);
}
@Override
public void onDismissScreen(Ad arg0) {
}
@Override
public void onFailedToReceiveAd(Ad arg0, AdRequest.ErrorCode arg1) {
}
@Override
public void onLeaveApplication(Ad arg0) {
}
@Override
public void onPresentScreen(Ad arg0) {
}
@Override
public void onReceiveAd(Ad arg0) {
}
private int getOffsetPosition(int position) {
return position - 1;
}
}
这是设置列表视图的自定义适配器:
class CustomMovieAdapter extends BaseAdapter {
private ArrayList<SearchResults> searchArrayList;
private LayoutInflater mInflater;
public CustomMovieAdapter(Context context, ArrayList<SearchResults> results){
searchArrayList = results;
mInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return searchArrayList.size()+2;
}
@Override
public Object getItem(int position) {
return searchArrayList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = new ViewHolder();
if(convertView == null){
convertView = mInflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
assert convertView != null;
holder.txtRating = (TextView) convertView.findViewById(R.id.movieRating);
holder.txtMovieName = (TextView) convertView.findViewById(R.id.movieName);
holder.txtMovieSize = (TextView) convertView.findViewById(R.id.movieSize);
holder.txtImdbRating = (TextView) convertView.findViewById(R.id.imdbScore);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.txtRating.setText(searchArrayList.get(position+1).getRating());
holder.txtMovieName.setText(searchArrayList.get(position+1).getName());
holder.txtMovieSize.setText(searchArrayList.get(position+1).getSize());
holder.txtImdbRating.setText(searchArrayList.get(position+1).getImdbRating());
return convertView;
}
class ViewHolder {
TextView txtRating;
TextView txtMovieName;
TextView txtMovieSize;
TextView txtImdbRating;
}
}
@Override
public int getCount() {
// Total count includes list items and ads.
return delegate.getCount() + 2;
}
您应该返回数据集的大小而不更改它。 如果需要显示更多项目,请将其添加到数据集中。 改变它
@Override
public int getCount() {
// Total count includes list items and ads.
return delegate.getCount() ;
}
应该解决您的异常。
编辑,在getView中,您应该避免篡改android为您提供的位置:
position+1
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