向上滚动列表视图时应用崩溃

Question

I have an app that have listview with 15 rows.And if there is new query to search,listivew be cleaned and adds new items to listview.But after some searchings in my app and add that items to list my app is being slow and when i try to scroll up it crashes.Here is my adapter

public class VideosAdapter extends BaseAdapter {

// The list of videos to display
public static List<Video> videos;
// An inflator to use when creating rows
private LayoutInflater mInflater;
private Context context;

/**
 * @param context this is the context that the list will be shown in - used to create new list rows
 * @param videos this is a list of videos to display
 */
public VideosAdapter(Context context, List<Video> videos) {
    VideosAdapter.videos = videos;
    this.mInflater = LayoutInflater.from(context);
    this.context = context;
}

@Override
public int getCount() {
    return videos.size();
}

@Override
public Object getItem(int position) {
    return videos.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    final Video video = videos.get(position);

    if(video.getTitle()==null && video.getDuration()==-1)
    {
        convertView = mInflater.inflate(R.layout.more_results, null);
        View thumbnail = convertView.findViewById(R.id.thumbnail);
        thumbnail.setVisibility(View.INVISIBLE);
        return convertView;
    }
        //animation = AnimationUtils.loadAnimation(context, R.anim.push_up_in);
            // If convertView wasn't null it means we have already set it to our list_item_user_video so no need to do it again
    else if(convertView == null){
        // This is the layout we are using for each row in our list
        // anything you declare in this layout can then be referenced below
        convertView = mInflater.inflate(R.layout.list_item_user_video, null);
    }
    UrlImageView thumb = (UrlImageView) convertView.findViewById(R.id.list_image);
    //TextView size=(TextView) convertView.findViewById(R.id.size);
    TextView duration=(TextView) convertView.findViewById(R.id.duration);
    TextView title = (TextView) convertView.findViewById(R.id.userVideoTitleTextView); 


    int durationmin=video.getDuration()/60;
    int durationsec=video.getDuration()%60;

    if(durationsec<10) duration.setText(durationmin+":0"+durationsec);
    else{
        duration.setText(durationmin+":"+durationsec);
    }
     // thumb image

    // Get a single video from our list
    // Set the image for the list item
    thumb.setImageDrawable(video.getThumbUrl());
    // Set the title for the list item

    title.setText(video.getTitle());

    /*animation.setDuration(1000);
    convertView.startAnimation(animation);
    animation = null;*/

    return convertView;
}

I set adapter with this code.

    VideosAdapter adapter = new VideosAdapter(getContext(), Allvideos);
    setAdapter(adapter);

My logcat is like this.

08-22 15:53:40.557: E/InputEventReceiver(619): Exception dispatching input event.
08-22 15:53:40.657: E/AndroidRuntime(619): FATAL EXCEPTION: main
08-22 15:53:40.657: E/AndroidRuntime(619): java.lang.NullPointerException
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.skymaster.tut.ui.adapter.VideosAdapter.getView(VideosAdapter.java:108)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.AbsListView.obtainView(AbsListView.java:2255)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.ListView.makeAndAddView(ListView.java:1769)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.ListView.fillUp(ListView.java:706)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.ListView.fillGap(ListView.java:645)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.AbsListView.trackMotionScroll(AbsListView.java:5040)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.AbsListView.scrollIfNeeded(AbsListView.java:3197)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.widget.AbsListView.onTouchEvent(AbsListView.java:3471)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.View.dispatchTouchEvent(View.java:7127)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2170)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1905)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2176)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1919)
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1925)
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1379)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.app.Activity.dispatchTouchEvent(Activity.java:2396)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.dispatchTouchEvent(ActionBarActivityDelegateICS.java:268)
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1873)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.View.dispatchPointerEvent(View.java:7307)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3174)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3119)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4155)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4134)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4226)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:163)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:4205)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:4245)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.Choreographer.doCallbacks(Choreographer.java:555)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.Choreographer.doFrame(Choreographer.java:523)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.os.Handler.handleCallback(Handler.java:615)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.os.Handler.dispatchMessage(Handler.java:92)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.os.Looper.loop(Looper.java:137)
08-22 15:53:40.657: E/AndroidRuntime(619):  at android.app.ActivityThread.main(ActivityThread.java:4745)
08-22 15:53:40.657: E/AndroidRuntime(619):  at java.lang.reflect.Method.invokeNative(Native Method)
08-22 15:53:40.657: E/AndroidRuntime(619):  at java.lang.reflect.Method.invoke(Method.java:511)
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-22 15:53:40.657: E/AndroidRuntime(619):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-22 15:53:40.657: E/AndroidRuntime(619):  at dalvik.system.NativeStart.main(Native Method)

As you see in my code there is URLIMAGEVIEW in my layout for each rowWith this item i load different images from url for each rows.And While image is loading spinner appears until loading be finished.Can URLIMAGEVIEW be the reason of error,or slow my app?

EDIT:Now i posted my original logcat.And error is at this line.

 duration.setText(durationmin+":"+durationsec);  

Answer 1

Do you use notifyDataChanged() ? It permit you notify the observers everytime that you have changed the content of the view, in your case everytime List videos change you have to use notifyDataChanged() . http://developer.android.com/reference/android/widget/BaseAdapter.html#notifyDataSetChanged%28%29 .