Unsupported parameter type in @future Method Using Trigger

Hi, Friends you can't pass Sobjects as parameters into asynchronous methods. "Methods with the future annotation cannot take sObjects or objects as arguments." You can pass a list or set of ID's and then query for the objects inside the method. shown in below..


Trigger:

1. trigger test on Book__c (before Update) {  
2.     if(Trigger.isUpdate){  
3.         LIST<String> myOldObjectststId = new LIST<String>();  
4.         LIST<String> myNewObjectststId = new LIST<String>();  
5.           
6.         Set<String> opportunitysalesids = new Set<String> ();          
7.   
8.         for (Book__c  b1 : [Select Id from Book__c where id in :Trigger.old]) {   
9.            myOldObjectststId.add(b1.id);           
10.         }  
11.         for (Book__c  b2 : [Select Id from Book__c where id in :Trigger.new]) {   
12.            myNewObjectststId.add(b2.id);           
13.         }  
14.         MyObjectUpdateAfter.testMethodFuture(myOldObjectststId ,myNewObjectststId );  
15.     }  
16. }  

Class with Future Method:

1. public class MyObjectUpdateAfter{  
2.     @future  
3.     public static void testMethodFuture(LIST<String> myOldObjectstst,LIST<String> myNewObjectstst){  
4.         //Now use these Id of  myOldObjectstst & myNewObjectstst  
5.   
6.     }  
7. }