问题
I am getting force close errors while I try to scroll down my list View in fragment activity, which has 1 image View and 2 text view. I am beginner in android, so don't have that much knowledge except basic scenario in mostly used components of android.
No bitmap OOM error is there, as I checked without images too.
I am retrieving images from sd card from the path.
Here, is my logcat out put with errors.
04-05 18:07:02.868: E/AndroidRuntime(3257): FATAL EXCEPTION: main
04-05 18:07:02.868: E/AndroidRuntime(3257): java.lang.NullPointerException
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.example.prac.HomeUser$ReceiptAdapter.getView(HomeUser.java:861)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.AbsListView.obtainView(AbsListView.java:2588)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.ListView.makeAndAddView(ListView.java:1840)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.ListView.fillDown(ListView.java:681)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.ListView.fillGap(ListView.java:645)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.AbsListView.trackMotionScroll(AbsListView.java:6535)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.AbsListView.scrollIfNeeded(AbsListView.java:3664)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.widget.AbsListView.onTouchEvent(AbsListView.java:4492)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.View.dispatchTouchEvent(View.java:7677)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2395)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2119)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2134)
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2305)
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1575)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.app.Activity.dispatchTouchEvent(Activity.java:2470)
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2253)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.View.dispatchPointerEvent(View.java:7875)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3978)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3862)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5105)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5084)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5182)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:174)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:5155)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:5201)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:791)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.Choreographer.doCallbacks(Choreographer.java:591)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.Choreographer.doFrame(Choreographer.java:559)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:777)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.os.Handler.handleCallback(Handler.java:725)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.os.Handler.dispatchMessage(Handler.java:92)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.os.Looper.loop(Looper.java:176)
04-05 18:07:02.868: E/AndroidRuntime(3257): at android.app.ActivityThread.main(ActivityThread.java:5302)
04-05 18:07:02.868: E/AndroidRuntime(3257): at java.lang.reflect.Method.invokeNative(Native Method)
04-05 18:07:02.868: E/AndroidRuntime(3257): at java.lang.reflect.Method.invoke(Method.java:511)
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
04-05 18:07:02.868: E/AndroidRuntime(3257): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
04-05 18:07:02.868: E/AndroidRuntime(3257): at dalvik.system.NativeStart.main(Native Method)
Now here is my code..
class ReceiptAdapter extends BaseAdapter {
ArrayList<GetterSetter> receiptlist;
private LayoutInflater inflater;
// private int[] colors = new int[] { Color.parseColor("#C8A6DA"),
// Color.parseColor("#F6F4AB"), Color.parseColor("#A2C3D0"),
// Color.parseColor("#F1B4A1") };
private int[] colors = new int[] { Color.parseColor("#2280aee3"),
Color.parseColor("#22888888") };
public ReceiptAdapter(Context context,
ArrayList<GetterSetter> receiptlist) {
// TODO Auto-generated method stub
this.receiptlist = receiptlist;
// inflater = LayoutInflater.from(context);
// inflater = LayoutInflater.from(context.getApplicationContext());
inflater = (LayoutInflater) getActivity().getSystemService(
Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return receiptlist.size();
}
@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
ViewHolder holder = null;
if (convertView == null) {
// convertView = inflater.inflate(R.layout.custom_list, null);
convertView = inflater.inflate(R.layout.custom_list, parent,
false);
// if (position % 2 == 1) {
// convertView.setBackgroundColor(Color.BLUE);
// } else {
// convertView.setBackgroundColor(Color.CYAN);
// }
int colorPos = position % colors.length;
convertView.setBackgroundColor(colors[colorPos]);
holder = new ViewHolder();
holder.Title = (TextView) convertView.findViewById(R.id.name);
holder.Total = (TextView) convertView.findViewById(R.id.total);
holder.Img = (ImageView) convertView
.findViewById(R.id.profile_image);
Animation animation = null;
animation = AnimationUtils.loadAnimation(getActivity(),
R.anim.wave);
animation.setDuration(200);
convertView.startAnimation(animation);
animation = null;
convertView.setTag(holder);
} else {
convertView.getTag();
}
holder.Title.setText(receiptlist.get(position).getTitle());
holder.Total.setText(receiptlist.get(position).getTotal());
String path = receiptlist.get(position).getImg();
File fileImg = new File(path);
Bitmap bitmap = null;
if (fileImg.exists()) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 7;
bitmap = BitmapFactory.decodeFile(fileImg.getAbsolutePath(),
options);
// bitmap = BitmapFactory.decodeFile(fileImg.getAbsolutePath());
holder.Img.setImageBitmap(bitmap);
}
else
{
Bitmap icon = BitmapFactory.decodeResource(getActivity().getResources(),
R.drawable.no_image);
holder.Img.setImageBitmap(icon);
}
holder.Img.setScaleType(ScaleType.CENTER_CROP);
return convertView;
}
class ViewHolder {
TextView Title;
TextView Total;
ImageView Img;
}
}
and my async task in which in postExecute() I am calling the custom list adapter as,
ReceiptAdapter adapter = new ReceiptAdapter(getActivity(),
recList);
setListAdapter(adapter);
So, my question is where am I getting wrong?
I have searched many codes also on stackoverflow, too but I found the same errors of others but didn't get any good feasible solution, so if anybody could help me out in this, then it would be appreciated. Thanks a ton!
回答1:
Your holder is null, always. In method getView you assign null to holder.
In else you should assign tagged object to holder.
In your method, getView():
{
//...
} else {
holder = (ViewHolder)convertView.getTag();
}
来源：https://stackoverflow.com/questions/29457427/getting-force-close-while-scrolling-down-the-list-view-in-android