ArrayIndexOutOfBoundsException with custom Android Adapter for multiple views in ListView

问题

I am attempting to create a custom Adapter for my ListView since each item in the list can have a different view (a link, toggle, or radio group), but when I try to run the Activity that uses the ListView I receive an error and the app stops. The application is targeted for the Android 1.6 platform.

The code:

public class MenuListAdapter extends BaseAdapter {
 private static final String LOG_KEY = MenuListAdapter.class.getSimpleName();

 protected List<MenuItem> list;
 protected Context ctx;
 protected LayoutInflater inflater;

 public MenuListAdapter(Context context, List<MenuItem> objects) {
  this.list = objects;
  this.ctx = context;
  this.inflater = (LayoutInflater)this.ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 }

 @Override
 public View getView(int position, View convertView, ViewGroup parent) {
  Log.i(LOG_KEY, \"Position: \" + position + \"; convertView = \" + convertView + \"; parent=\" + parent);
  MenuItem item = list.get(position);
  Log.i(LOG_KEY, \"Item=\" + item );

        if (convertView == null)  {
            convertView = this.inflater.inflate(item.getLayout(), null);
        }

        return convertView;
 }

 @Override
 public boolean areAllItemsEnabled() {
  return false;
 }

 @Override
 public boolean isEnabled(int position) {
  return true;
 }

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

 @Override
 public MenuItem getItem(int position) {
  return this.list.get(position);
 }

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

 @Override
 public int getItemViewType(int position) {
  Log.i(LOG_KEY, \"getItemViewType: \" + this.list.get(position).getLayout());
  return this.list.get(position).getLayout();
 }

 @Override
 public int getViewTypeCount() {
  Log.i(LOG_KEY, \"getViewTypeCount: \" + this.list.size());
  return this.list.size();
 }

}

The error I receive:

    java.lang.ArrayIndexOutOfBoundsException
  at android.widget.AbsListView$RecycleBin.addScrapView(AbsListView.java:3523)
  at android.widget.ListView.measureHeightOfChildren(ListView.java:1158)
  at android.widget.ListView.onMeasure(ListView.java:1060)
  at android.view.View.measure(View.java:7703)

I do know that the application is returning from getView and everything seems in order.

Any ideas on what could be causing this would be appreciated.

Thanks,

-Dan

回答1:

The item view type you are returning from

getItemViewType() is >= getViewTypeCount().

回答2:

The accepted answer is correct. This is what I am doing to avoid the problem:

public enum FoodRowType {
    ONLY_ELEM,
    FIRST_ELEM,
    MID_ELEM,
    LAST_ELEM
}

@Override
public int getViewTypeCount() {
    return FoodRowType.values().length;
}

@Override
public int getItemViewType(int position) {
    return rows.get(position).getViewType();  //returns one of the above types
}

回答3:

Issue comes when getItemType value is wrong. This value should be an integer and should be from 0 to getViewTypeCount()-1.

回答4:

The reason, is most likely because the getItemViewType method is returning the wrong values! Each row in listview is a one View. While scrooling getItemViewType reach more than View's count.

What to do? How to avoid issue?

First determine view(row) in your listview that is shown first.While Scrolling use moduler equation

    @Override
    public int getItemViewType(int position) {
        return choseType(position);//function to use modular equation
    }
    @Override
    public int getViewTypeCount() {
        return 10;
    }

In this example there is ten view(10 row).

private  int choseType(int position){
    if(position%10==0)
        return 0;
    else if(position%10==1)
        return 1;
    else if(position%10==2)
        return 2;
    else if(position%10==3)
        return 3;
    else if(position%10==4)
        return 4;
    else if(position%10==5)
        return 5;
    else if(position%10==6)
        return 6;
    else if(position%10==7)
        return 7;
    else if(position%10==8)
        return 8;
    else
        return 9;


}

Important

Some users mentioned on another question on stackoverflow that method

public int getViewTypeCount() and public int getItemViewType(int position) fix like Tooglebutton automaticly enable state check true on scrooling..that is big wrong .If you dont want automatic enbale on scrool just do

toogleButton.setChecked(false);

on getView override method.

来源：https://stackoverflow.com/questions/2596547/arrayindexoutofboundsexception-with-custom-android-adapter-for-multiple-views-in

标签

android

exception

listview

adapter