android - Gridview populating issue with asynctask -

i'm trying populate gridview thumbnail images i'm having issues decoding images within asynctask. when start app, images loaded 1 1 , images not displayed correctly ( once scroll shows top image , loads original later). here code :

public class imageadapter extends baseadapter {     private context mcontext;     private list<string> mlist;     private int mheight;     private int mwidth;     private inputstream is;      public imageadapter(context context, list<string> list, int height, int width) {         mcontext = context;         mlist = list;         mheight = height;         mwidth = width;     }       @override     public int getcount() {         return mlist.size();     }      @override     public object getitem(int position) {         return mlist.get(position).tostring();     }      @override     public long getitemid(int position) {         return 0;     }      @override     public view getview(int position, view convertview, viewgroup parent) {         imageview imageview;         if (convertview == null) {             imageview = new imageview(mcontext);         } else {             imageview = (imageview) convertview;         }           inputstream is;         try {             = mcontext.getassets().open(mlist.get(position));             loadimage task = new loadimage(imageview , mheight , mwidth);             task.execute(is);         } catch (ioexception e) {             // todo auto-generated catch block             e.printstacktrace();         }          return imageview ;      }      public class loadimage extends asynctask<inputstream, void, bitmap>{         private final weakreference<imageview> imageviewreference;           private inputstream = null;         private int width;           public loadimage(imageview imageview, int mheight, int mwidth) {              imageviewreference = new weakreference<imageview>(imageview);              this.width=mwidth;              // todo auto-generated constructor stub         }          @override         protected bitmap doinbackground(inputstream... params) {             = params[0];              if (is !=null) {                  bitmap bitmap  = bitmapfactory.decodestream(is);                 bitmap nbitmap =bitmap.createscaledbitmap(bitmap,width/3 , width/3, false);                 return nbitmap;                  }             return null;            }          @override          protected void onpostexecute(bitmap bitmap) {             if (imageviewreference != null && bitmap != null) {                 final imageview imageview = imageviewreference.get();                 if (imageview != null) {                     imageview.setimagebitmap(bitmap);                     imageview.setscaletype(imageview.scaletype.center_crop);                 }           }     } } 

i highly recommend universal image loader. has need: gridview can loaded thumbnails. has memory , disk cache features, along logging , features thread pool sizes. give try; works me , should fit needs.