关于GridView Android的问题

Question

I have created gridview with 20 items. I have used custom adapter to bind this gridview. When i scroll in gridview the index of the items have been change, or sometime some of the items have been invisible. N some times whole gridview has been invisible. Not know what's worng with it.

      public class MyAdapter extends BaseAdapter {

        final int NumberOfItem = 90;
        private Bitmap[] bitmap = new Bitmap[NumberOfItem];

        View grid;

        private Context context;
        private LayoutInflater layoutInflater;

        MyAdapter(Context c){
         context = c;
         layoutInflater = LayoutInflater.from(context);

         //init dummy bitmap,
         //using R.drawable.icon for all items
       /*  for(int i = 1; i < NumberOfItem; i++){
          bitmap[i] = BitmapFactory.decodeResource(context.getResources(), R.drawable.image1);
         }*/
        }

        @Override
        public int getCount() {
         // TODO Auto-generated method stub
         return imageIDs.length;
        }

        @Override
        public Object getItem(int position) {
         // TODO Auto-generated method stub
         return position;
        }

        @Override
        public long getItemId(int position) {
         // TODO Auto-generated method stub
         return position;
        }

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
         // TODO Auto-generated method stub


         if(convertView==null){
          grid = new View(context);
          grid = layoutInflater.inflate(R.layout.main, null);

          ImageView imageView = (ImageView)grid.findViewById(R.id.image);
          imageView.setBackgroundResource(imageIDs[position]);


          TextView textView = (TextView)grid.findViewById(R.id.text);
          textView.setText(names[position]);


         }else{

             grid = (View)convertView;


         }


         return grid;
        }


        Integer[] imageIDs = {

                R.drawable.attorneys_180, R.drawable.auto_repair_180, R.drawable.coffee_180, R.drawable.gas_stations_180,
                R.drawable.grocery_180, R.drawable.hotels_180, R.drawable.locksmith_180, R.drawable.nightclubs_180,
                R.drawable.plumbers_180

        };

        String[] names = {"Attorneys","Auto Repair","Coffee","Gas Stations","Grocery","Hotels","Locksmith","NightClubs","Plumbers"};


    }

content of main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content" android:gravity="center">

<ImageView
android:id="@+id/image"
android:layout_width="67dp"
android:layout_height="67dp" android:background="@drawable/ic_launcher"/>

<TextView
 android:id="@+id/text"
 android:layout_width="fill_parent"
 android:layout_height="wrap_content"
 android:layout_alignRight="@+id/image"
 android:layout_below="@+id/image"
 android:text="gsdfgsd"
 android:textColor="#000000" android:gravity="center"/>

 </RelativeLayout>

Give me right solution for it.

Thanks, Jay Patel

Answer 1

It's a bit difficult to spot the error without seeing the rest of the code of the Activity, but we can start from fixing the getView method (I've added some comments next to the changes I've made):

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) 
    {
         if(convertView == null){
             //grid = new View(context); You don't need this because next line creates it for you
             grid = layoutInflater.inflate(R.layout.main, null);
         }
         else
         {
             grid = convertView;
         }

         // You always need to set the right image and text, even when you have a non-null convertView

         ImageView imageView = (ImageView)grid.findViewById(R.id.image);
         imageView.setBackgroundResource(imageIDs[position]);

         TextView textView = (TextView)grid.findViewById(R.id.text);
         textView.setText(names[position]);

         return grid;
    }