android - How to dynamically load images in GridView or how to optimazi it's work? -

my application has gridview control display photos directory. if directory consist of 1000 or 2000 photos, gridview slow, because of loading photos @ once.

is possible implement gradual loading of photos, example, after view 100 photos, loaded 100? or there more ways optimize speed of gridview? grateful advice.

my code

activity_main.xml

the piece of code demonstrate gridview  <gridview     android:id="@+id/gridview"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:columnwidth="90dp"     android:numcolumns="auto_fit"     android:verticalspacing="10dp"     android:horizontalspacing="10dp"     android:stretchmode="columnwidth"     android:gravity="center"/> 

mainactivity.java

public class mainactivity extends activity {  imageadapter myimageadapter;  @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);      gridview gridview = (gridview) findviewbyid(r.id.gridview);     myimageadapter = new imageadapter(this);     gridview.setadapter(myimageadapter);      string externalstoragedirectorypath = environment             .getexternalstoragedirectory()             .getabsolutepath();      string targetpath = externalstoragedirectorypath + "/dcim/100andro";      toast.maketext(getapplicationcontext(), targetpath, toast.length_long).show();     file targetdirector = new file(targetpath);      file[] files = targetdirector.listfiles();     (file file : files){         myimageadapter.add(file.getabsolutepath());     } }  public class imageadapter extends baseadapter {      private context mcontext;     arraylist<string> itemlist = new arraylist<string>();      public imageadapter(context c) {         mcontext = c;     }      void add(string path){         itemlist.add(path);     }      @override     public int getcount() {         return itemlist.size();     }      @override     public object getitem(int arg0) {         return null;     }      @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);             imageview.setlayoutparams(new gridview.layoutparams(220, 220));             imageview.setscaletype(imageview.scaletype.center_crop);             imageview.setpadding(8, 8, 8, 8);         } else {             imageview = (imageview) convertview;         }          bitmap bm = decodesampledbitmapfromuri(itemlist.get(position), 220, 220);          imageview.setimagebitmap(bm);         return imageview;     }      public bitmap decodesampledbitmapfromuri(string path, int reqwidth, int reqheight) {          bitmap bm = null;          final bitmapfactory.options options = new bitmapfactory.options();         options.injustdecodebounds = true;         bitmapfactory.decodefile(path, options);          options.insamplesize = calculateinsamplesize(options, reqwidth, reqheight);          options.injustdecodebounds = false;         bm = bitmapfactory.decodefile(path, options);          return bm;     }      public int calculateinsamplesize(              bitmapfactory.options options, int reqwidth, int reqheight) {         final int height = options.outheight;         final int width = options.outwidth;         int insamplesize = 1;          if (height > reqheight || width > reqwidth) {             if (width > height) {                 insamplesize = math.round((float)height / (float)reqheight);             } else {                 insamplesize = math.round((float)width / (float)reqwidth);             }         }          return insamplesize;     }  } 

}

you should use library load images, known ones glide (https://github.com/bumptech/glide) , picasso (http://square.github.io/picasso/). both of handle cache you, , lazy loading grid should work flawlessly.