public with sharing class AttachController {

//private ApexPages.StandardController controller { get; set; }
public List<Deal_License__c> dp{get;set;}
public List<Contact> con{get;set;}

   public Deal__c D{get;set;}
    public AttachController(ApexPages.StandardController controller) {
    try
    {
     D = [Select Name,Id,VersionNo__c,Account__c,Account__r.Name,Account_Executive__r.Name,License_Value__c,Account__r.BillingStreet,Account__r.BillingCity,Account__r.Billingstate,Account__r.BillingPostalcode,Account__r.BillingCountry
                 from Deal__c where id=:controller.getRecord().id];
    system.debug('TestDeal'+D);
    Account acc=[Select Id,BillingStreet,BillingCity,Billingstate,BillingPostalcode,BillingCountry from Account where id=:D.Account__c];
    system.debug('Account%%%%%%%%%%%%%%'+acc);
    dp=[select id,Name,Deal__c,Months__c,List_Price__c,Unit_Price__c,Quantity__c,Total_Value__c,Ingram_Transfer_Price__c,Ingram_Special_Price__c,Ingram_Purchase_Value__c,Start_Date__c,End_Date__c from Deal_License__c where Deal__c=:D.Id];
    System.debug('DEALPRDODUCT&&&&&&&&&&'+dp);
    con=[select Id,Name,Email,Phone,MobilePhone from Contact  where id=:D.Account_Executive__c];
   
    }
    catch(Exception e)
    {
    system.debug('Exception'+e);
    }
    }
    
    public void attach() {
        try{
           Deal__c D=new Deal__c();
            Attachment myAttach = new Attachment();
            myAttach.ParentId = ApexPages.currentPage().getParameters().get('id');
            System.debug('Id: ' + ApexPages.currentPage().getParameters().get('id'));
            List<Attachment> at=[Select id from Attachment where parentId=:myAttach.ParentId];
            Integer c=at.size()+1;
            system.debug('Account%%%%%%%%%%%%%%'+c);
            myAttach.name =''+''+ c +'';
            PageReference psPdf = new PageReference('/apex/Quotation?id=' + ApexPages.currentPage().getParameters().get('id'));
            myAttach.body = psPdf.getContentAsPdf();

            insert myAttach;
            D.VersionNo__c=myAttach.name;
            update D;
          
            
              
            
                       
            System.debug('After attach');
            System.debug(myAttach);

            
            /*
            ApexPages.addMessage(new ApexPages.Message

(ApexPages.Severity.CONFIRM,'Quotation has been attached.'));
            */
        }
        catch(Exception e) {
            ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.FATAL,'There was an error while attaching'));
            System.debug('Exception');
        }
    }
    
   public PageReference QA() {
   
     PageReference secondPage = new PageReference('/apex/EmailQuote?id=' + ApexPages.currentPage().getParameters().get('id'));

      Attachment myAttach = new Attachment();
            myAttach.ParentId = ApexPages.currentPage().getParameters().get('id');
            System.debug('Id: ' + ApexPages.currentPage().getParameters().get('id'));
            List<Attachment> at=[Select id from Attachment where parentId=:myAttach.ParentId];
            Integer c=at.size()+1;
            myAttach.name = ''+''+ c +'';
            PageReference psPdf = new PageReference('/apex/Quotation?id=' + ApexPages.currentPage().getParameters().get('id'));
           try{
                myAttach.body = psPdf.getContentAsPdf();
               }
        catch(Exception e){}
//insert myAttach;
              secondPage.setRedirect(true);
              return secondPage;
              }
            
    
    public PageReference back() {
        attach();
        PageReference pr = new PageReference('/' + ApexPages.currentPage().getParameters().get('id') +'#'+ ApexPages.currentPage().getParameters().get('id') + '_RelatedNoteList_target');
        pr.setRedirect(true);
        System.debug('Inside back');
        return pr;
    }
       public PageReference cancel() {
       PageReference pr = new PageReference('/' + ApexPages.currentPage().getParameters().get('id') +'#'+ ApexPages.currentPage().getParameters().get('id') + '_RelatedNoteList_target');
       pr.setRedirect(true);
       System.debug('Inside back');
       return pr;
       }
       
    
      
     /*public String attachmentName{get; set;}
      public pagereference AttachQuote(){
        Pagereference pdf = page.Quotation;
        blob  b=pdf.getcontent();
      
         attachment att = new attachment();
         att.parentId = ApexPages.currentPage().getParameters().get('id') ;
         att.body = b;
         att.name = 'Quotation.pdf';     
         insert att;
         return null;
         
         
      
      }*/
       /*test methods here*/
     public  static testMethod void testAttachController()
      {    
       Profile p = [SELECT Id FROM Profile WHERE Name='Standard User']; 
  
 User U = new User(Alias = 'TUser1', Email='testItemaster1@im.com',EmailEncodingKey='UTF-8',
   LastName='TestingAcc1', LanguageLocaleKey='en_US',LocaleSidKey='en_US', ProfileId =p.Id,
   TimeZoneSidKey='America/Los_Angeles', UserName='testacc1@test.com');   
 insert U;
        
        Account acc=new Account

(Name='rose',BillingCity='bang',Billingstate='kat',BillingPostalcode='560000',BillingCountry='india');
        insert acc;
         system.debug('########555'+ acc);
        Deal__c opp=new Deal__c(Name='test12',Account__c=acc.id);
        insert opp;
        system.debug('########7765'+ opp);
     
                
        Attachment myAttach1 = new Attachment();
        myAttach1.ParentId =opp.id;
        myAttach1.name = 'Quotation.pdf';
        myAttach1.body = blob.valueof('test');
          
        insert myAttach1;
        
        
        system.debug('Attahment1'+ myAttach1);
     
        AttachController atc = new AttachController(new ApexPages.StandardController(opp));
        system.debug('%%%%%'+atc);
        PageReference pageRef = Page.Quotation;
        pageRef.getParameters().put('id', String.valueOf(opp.Id));
        Test.setCurrentPage(pageRef);
       Blob b;

       ApexPages.currentPage().getParameters().put('id', opp.id);
       AttachController atc1 = new AttachController(new ApexPages.StandardController(myAttach1));
        //ApexPages.StandardController stc = new ApexPages.StandardController(opp);  
        //AttachController qe = new AttachController(stc);
         
         // qe.QA();
        atc.attach();
        //atc.QA();
        atc.back();
        atc.cancel();
        atc.QA();
       
        return;
        
       /* public PageReference QA() {
     PageReference secondPage = new PageReference('/apex/EmailQuote?id=' + 

ApexPages.currentPage().getParameters().get('id'));
        
       insert myAttach1;
       secondPage.setRedirect(true);   
            return secondPage;
            }*/
     
      //Attachment atchoo = [Select Id,  From Attachment where Name like 'Quotation.pdf' 


       /* if (Test.isRunningTest())
{
   b=Blob.valueOf('Test Blob String');
}
else
{
  b= pageRef.getContent();
}*/

         }
         
      }

 I want to get the myattach.name in VersionNo__c field of Deal__c object shoulb get updated

Ref Line no:42