android - AsyncTask won't let me use my own class -

i have asynctask load entries in listview creating everytime new instance of class, varaibles saved , let them load own adapter extended baseadapter.

the class looks this:

public class pictureresults {     private long id;     private string pictureurl;      public void setid(long id)     {         this.id = id;     }      public long getid()     {         return id;     }      public void setpictureurl(string pictureurl)     {         this.pictureurl = pictureurl;     }      public string getpictureurl()     {         return pictureurl;     } } 

this asynctask class:

private class getpicturedatatask extends asynctask<long, string, void>     {         protected pictureresults doinbackground(long... param)         {                 pictureresults pr;                  pr = new pictureresults();                 pr.setid(param[0]);                 pr.setpictureurl("http://www.myurl.com");                  return pr;         }          protected void onprogressupdate(string... response)         {             //do nothing         }          protected void onpostexecute(pictureresults ret)         {             picresults.add(ret); //picresults arraylist<pictureresults>             ret.loadpicture(customadapter);             customadapter.notifydatasetchanged();         }     } 

the main problem appears eclipse let me know following:

the return type incompatible asynctask<long,string,void>.doinbackground(long[]) 

it important customadapter.notifydatasetchanged(); executed in onpostexecute because in onprogressupdate app crashes causing of changing listview background thread.

why can't use pictureresults type???

btw: how execute asynctask:

long hey = (long) 1; new getpicturedatatask().execute(hey); 

the third type parameter of asynctask should pictureresults not void

class getpicturedatatask extends asynctask<long, string, pictureresults> 

because 3rd parameter type of asynctask kind of data result should returned. if don't want return result doinbackground(), use void , return null;