android - Change image dynamically into a ListView from JSON -

i have following code retrivieng data url in json format , updating listview. code working perfectly. in xml layout, have 2 textview , 1 imageview.

how can update imageview dinamically?

i'm not getting images url, images stored inside project (res/drawable folder). var tag_icon has name of image exact same name of image inside project.

example:

response json: tag_icon = lamp01

name of image: lamp01.png

this main class:

public class devicelist extends listactivity  {          private static string url = "http://192.168.10.2/myhome/get_all_devices.php";          // hashmap listview         arraylist<hashmap<string, string>> devicelist = new arraylist<hashmap<string, string>>();          // class json         jsonparser jparser = new jsonparser();          // criar json nodes         private static final string tag_devices = "devices";         private static final string tag_id = "id";         private static final string tag_name = "name";         private static final string tag_description = "description";         private static final string tag_icon = "icon";          // array jsonarray         jsonarray devices = null;          @override         public void oncreate(bundle savedinstancestate) {             super.oncreate(savedinstancestate);             setcontentview(r.layout.device_list);              // loat listview             new loaddevices().execute();             listview lv = getlistview();         }          // class loaddevices         class loaddevices extends asynctask<string, string, string>{             @override                    protected void onpreexecute(){                           super.onpreexecute();                                }              protected string doinbackground(string... args) {                     // json string url                 jsonobject json = jparser.getjsonfromurl(url);                  try {                 // add array                 devices = json.getjsonarray(tag_devices);                  // looping trough results                 for(int = 0; < devices.length(); i++){                     jsonobject c = devices.getjsonobject(i);                      // storing each json item in variable                     string id = c.getstring(tag_id);                     string name = c.getstring(tag_name);                     string description = c.getstring(tag_description);                     string icon = c.getstring(tag_icon);                       // creating hashmap                     hashmap<string, string> map = new hashmap<string, string>();                           map.put(tag_id, id);                     map.put(tag_name, name);                                         map.put(tag_description, description);                     map.put(tag_icon, icon);                       devicelist.add(map);                 }             } catch (jsonexception e) {                 e.printstacktrace();             }                 return null;             }              protected void onpostexecute(string file_url){                        runonuithread(new runnable() {                                   public void run() {                         // update json listview                          listadapter adapter = new simpleadapter(devicelist.this, devicelist,r.layout.device_row,                                 new string[]{                                     tag_name,                                     tag_description,                                 },                                  new int[] {                                     r.id.device_row_textviewname,                                     r.id.device_row_textviewdescription,                                 });                          // update listview                           setlistadapter(adapter);                     }                 });             }         }         } 

here's xml layout single row

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@+id/device_row_relativelayout"     android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:background="@drawable/list_selector"     android:orientation="horizontal"     android:padding="5dip" >       <linearlayout         android:id="@+id/device_row_linearlayout"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignparentleft="true"         android:layout_marginright="5dip"         android:padding="3dip" >         <imageview             android:id="@+id/device_row_imageviewicon"             android:contentdescription="@string/app_name"             android:layout_width="60dip"             android:layout_height="60dip"             android:src="@drawable/lamp03" />     </linearlayout>        <textview         android:id="@+id/device_row_textviewname"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_aligntop="@+id/device_row_relativelayout"         android:layout_margintop="5dip"         android:layout_marginleft="75dip"         android:layout_torightof="@+id/device_row_imageviewicon"         android:text="lâmpada quarto"         android:textcolor="#4169e1"         android:textsize="20dip"         android:textstyle="bold"         android:typeface="sans" />      <textview         android:id="@+id/device_row_textviewdescription"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/device_row_textviewname"         android:layout_marginbottom="5dip"         android:layout_alignleft="@+id/device_row_textviewname"         android:paddingtop="1dip"         android:layout_marginright="15dip"         android:layout_centerhorizontal="true"         android:text="usado para controlar lâmpada quarto."         android:textcolor="#343434"         android:textsize="13dip" />  </relativelayout> 

if images in drawable folder need first use title find image in drawable folder. make sure title of file same title tag returning server.

int imageid = getresources().getidentifier("yourpackagename:drawable/" + tag_title, null, null); 

then find imageview , set image

imageview picture = (imageview)findviewbyid(r.id.device_row_imageviewicon); picture.setimageresource(imageid);