Hi, 

Below controller is a wrapper class using pagination.  Issue I am facing here is I am displaying pages in pagination User can select rows and insert the data. 

 Problem here is previous selected rows once moved to next page is not getting stored. 

 Only the currect page which is selected are getting stored not the previous page. Please suggest me how to fix. 

Controller
public with sharing class CCW_ContactPaginationController {

  //URL Passing Parameters.
  String PageContractId = ApexPages.currentPage().getParameters().get('ContractId');    
  String PageAccountId  = ApexPages.currentPage().getParameters().get('AccountId');  

  public Asset GetAccount{get;set;}
  public Asset GetContract{get;set;}
  public Asset GetExpireDate{get;set;}
  public Asset GetReseller{get;set;}
  public Asset GetDistributor{get;set;}
  public Boolean IncumbentReseller{get;set;}
  public Boolean Education{get;set;}
  public Asset GetOpportunity{get;set;}
  public Asset GetNewOpportunity{get;set;}
  public String ExpireTerms{get;set;}

  //Our collection to class/wrapper objects wrapAsset
  public List<CCWRowItem> wrapAssetList {get; set;}
  public List<Asset> selectedAssets{get;set;}
   /*
    *   item in context from the page
    */
    public String contextItem{get;set;}


    /*
    *   set controller
    */
    private ApexPages.StandardSetController setCon;
   
   
    /*
    *   the contact ids selected by the user
    */
    private Set<Id> selectedContactIds;
   
   
    /*
    *   constructor
    */
    public CCW_ContactPaginationController ()
    {
      GetAccount = new Asset();    //Get Account Id from Page
      GetContract = new Asset();   //Get Contract Name from Page  
      GetExpireDate = new Asset();   // Date Picker  
      GetReseller = new Asset();
      GetDistributor = new Asset(); 
      GetOpportunity = new Asset();   // Get Opportunity Id
      GetNewOpportunity = new Asset();  // Get New Opportunity Name      
      fetch_data();       
     }
   
  // public List<Asset> Asset_yourObjList{get;set;}
    
   public void fetch_data ()
   {
      
        //init variable
        this.selectedContactIds= new Set<Id>();
        //gather data set
       
         If ( GetAccount.AccountId == NULL || GetContract.Name == NULL )
         {  
           If ( PageContractId <> NULL )
           {
           Contract C;
           C = [SELECT Name FROM Contract WHERE Id = :PageContractId Limit 1];
           this.setCon = new ApexPages.StandardSetController( [SELECT AccountId,Product2Id,SerialNumber,last_contract_number__c,Service_Start_Date_Min__c, Service_End_Date_Max__c,InstallDate FROM Asset WHERE last_contract_number__c = :C.Name  Limit 1000] );
                     }
           else If ( PageAccountId <> NULL )
           {
           this.setCon = new ApexPages.StandardSetController( [SELECT AccountId,Product2Id,SerialNumber,last_contract_number__c,Service_Start_Date_Min__c, Service_End_Date_Max__c,InstallDate FROM Asset WHERE AccountId = :PageAccountId  Limit 1000] );
                     }  
         }
        
          If ( GetAccount.AccountId <> NULL && GetContract.Name == NULL )
          { 
           this.setCon = new ApexPages.StandardSetController( [SELECT AccountId,Product2Id,SerialNumber,last_contract_number__c,Service_Start_Date_Min__c, Service_End_Date_Max__c,InstallDate FROM Asset WHERE AccountId = :GetAccount.AccountId Limit 1000] );
                    }
          Else If ( GetContract.Name <> NULL && GetAccount.AccountId == NULL )
          {
           this.setCon = new ApexPages.StandardSetController( [SELECT AccountId,Product2Id,SerialNumber,last_contract_number__c,Service_Start_Date_Min__c, Service_End_Date_Max__c,InstallDate FROM Asset WHERE last_contract_number__c  = :GetContract.Name Limit 1000] );
                    } 
         Else If ( GetAccount.AccountId <> NULL && GetContract.Name <> NULL )
          {
         this.setCon = new ApexPages.StandardSetController( [SELECT AccountId,Product2Id,SerialNumber,last_contract_number__c,Service_Start_Date_Min__c, Service_End_Date_Max__c,InstallDate FROM Asset WHERE AccountId = :GetAccount.AccountId and last_contract_number__c = :GetContract.Name  Limit 1000] );
                   }                                    
        this.setCon.setpageNumber(1);
        this.setCon.setPageSize(10);     
                  
   }
  
      
    /*
    *   handle item selected
    */
    public void doSelectItem(){       
        this.selectedContactIds.add(this.contextItem);       
    }
   
   
    /*
    *   handle item deselected
    */
    public void doDeselectItem(){       
        this.selectedContactIds.remove(this.contextItem);       
    }
   
   
    /*
    *   return count of selected items
    */
    public Integer getSelectedCount(){
       
        return this.selectedContactIds.size();
       
    }
   
   
    /*
    *   advance to next page
    */
    public void doNext(){
       
        if(this.setCon.getHasNext())
            this.setCon.next();

    }
   
   
    /*
    *   advance to previous page
    */
    public void doPrevious(){
       
        if(this.setCon.getHasPrevious())
            this.setCon.previous();
               
    }
   
    //public List<CCWRowItem> rows = new List<CCWRowItem>();
   
    public List<CCWRowItem> rows {get; set;}
    /*
    *   return current page of groups
    */
    public List<CCWRowItem> getContacts(){       
       
        rows = new List<CCWRowItem>();
       
        for(sObject r : this.setCon.getRecords()){
            Asset c = (Asset)r;
           
            CCWRowItem row = new CCWRowItem(c);
            if(this.selectedContactIds.contains(c.Id)){
                row.IsSelected=true;
            }
            else{
                row.IsSelected=false;
            }
            rows.add(row);           
        }
               
        return rows;
       
    }
 
// Store Selected Records to Object/Table
public void processSelected() {
    selectedAssets = new List<Asset>();
    list<Temp_Assets__c> TempAssetList = new list<Temp_Assets__c>();   
       
        for(CCWRowItem wrapAssetObj : rows  ) {
          if(wrapAssetObj.IsSelected == true) {
             selectedAssets.add(wrapAssetObj.tContact);
           } 
     }
       
       
       Account ResellerAct;
       Account DistributorAct; 
       Opportunity Oppt;        
                        
       for(Asset Act : selectedAssets)
            {              
              Temp_Assets__c TempAsset = new Temp_Assets__c();
              TempAsset.Name = 'Sudhir';
              TempAsset.AccountId__c = Act.AccountId;
              TempAsset.Product__c = Act.Product2Id;
              TempAsset.Serial_Number__c = Act.SerialNumber;
              TempAsset.Last_Contract_Number__c = Act.last_contract_number__c;
              TempAsset.Service_Start_Date__c = Act.Service_Start_Date_Min__c;
              TempAsset.Service_End_Date__c = Act.Service_End_Date_Max__c;
              //TempAsset.Service_End_Date__c = maxDate;
              TempAsset.Install_Date__c = Act.InstallDate; 
               If (GetReseller.AccountId <> NULL)
               {     
                ResellerAct = [ SELECT Id FROM Account WHERE ID = :GetReseller.AccountId Limit 1];
                TempAsset.Reseller__c = ResellerAct.Id;
                }
               If (GetDistributor.AccountId <> NULL )
                {
                DistributorAct = [ SELECT Id FROM Account WHERE ID = :GetDistributor.AccountId Limit 1];
                TempAsset.Distributor__c = DistributorAct.Id;
                }
               If ( GetOpportunity.Opportunity__c <> NULL )
                {
                Oppt = [SELECT Id FROM Opportunity WHERE ID = :GetOpportunity.Opportunity__c Limit 1];
                TempAsset.Existing_Opportunity__c = Oppt.Id;
                }               
              TempAsset.Incumbent_Reseller__c = IncumbentReseller;
              TempAsset.Education__c = Education;
              TempAsset.Expiry_Date__c = GetExpireDate.Expire_Date__c;
             
              TempAsset.New_Opportunity__c = GetNewOpportunity.New_Opportunity__c;
              TempAsset.Expiry_Term__c = ExpireTerms;
              //Add the selected Assets to the List
              TempAssetList.add(TempAsset);
            }
           
        Insert TempAssetList; 
       
    } 
   
    /*
    *   return whether previous page exists
    */
    public Boolean getHasPrevious(){
       
        return this.setCon.getHasPrevious();
       
    }
   
   
    /*
    *   return whether next page exists
    */
    public Boolean getHasNext(){
       
        return this.setCon.getHasNext();
   
    }
   
   
    /*
    *   return page number
    */
    public Integer getPageNumber(){
       
        return this.setCon.getPageNumber();
       
    }
   
   
    /*
    *    return total pages
    */
    Public Integer getTotalPages(){
   
        Decimal totalSize = this.setCon.getResultSize();
        Decimal pageSize = this.setCon.getPageSize();
       
        Decimal pages = totalSize/pageSize;
       
        return (Integer)pages.round(System.RoundingMode.CEILING);
    }
   
   
   
    /*
    *   helper class that represents a row
    */
    public with sharing class CCWRowItem{
       
        public Asset tContact{get;set;}
        public Boolean IsSelected{get;set;}
       
        public CCWRowItem(Asset c){
            this.tContact=c;
            this.IsSelected=false;
        }
       
    }
   
    
   
}

Visual Force


<apex:page controller="CCW_ContactPaginationController" showHeader="false" sidebar="false" readOnly="false" cache="false">
 
    <script type="text/javascript">

        /*
        *    function to handle checkbox selection
        */
        function doCheckboxChange(cb,itemId){

            if(cb.checked==true){
                aSelectItem(itemId);
            }
            else{
                aDeselectItem(itemId);
            }

        }

    </script>
   
<apex:sectionHeader subtitle="Create Renewal Quote" title="Meru Networks"/>

<apex:form >
              
       
     <apex:pageBlock >
       <apex:pageBlockButtons >
       <apex:commandButton value="Save Records" action="{!processSelected}"/>
       </apex:pageBlockButtons>
           
       <apex:pageBlockSection title="Install Base Report" id="mpb" collapsible="true" columns="1">
       
       
        <!-- handle selected item -->
        <apex:actionFunction name="aSelectItem" action="{!doSelectItem}" rerender="mpb">
            <apex:param name="contextItem" value="" assignTo="{!contextItem}"/>
        </apex:actionFunction>
       
        <!-- handle deselected item -->
        <apex:actionFunction name="aDeselectItem" action="{!doDeselectItem}" rerender="mpb">
            <apex:param name="contextItem" value="" assignTo="{!contextItem}"/>
        </apex:actionFunction>
           
            <!-- table of data -->
            <apex:pageBlockTable title="Assets" value="{!Contacts}" var="c">
                <apex:column >
                    <apex:facet name="header">Action</apex:facet>
                    <apex:inputCheckbox value="{!c.IsSelected}" onchange="doCheckboxChange(this,'{!c.tContact.Id}')"/>
                </apex:column>
                <apex:column value="{!c.tContact.AccountId}"/>
                <apex:column value="{!c.tContact.Product2Id}"/>
                <apex:column value="{!c.tContact.SerialNumber}"/>
                <apex:column value="{!c.tContact.last_contract_number__c}"/>
                <apex:column value="{!c.tContact.Service_Start_Date_Min__c}"/>
               <apex:column value="{!c.tContact.Service_End_Date_Max__c}"/>
               <apex:column value="{!c.tContact.InstallDate}"/>
            </apex:pageBlockTable>
       
           
           
            <apex:pageBlockSection collapsible="false" columns="4">
            <!-- count of selected items -->
            <apex:outputLabel value="[{!selectedCount} records selected]" />           
            <apex:outputLabel value=" (page {!pageNumber} of {!totalPages}) " />          
            <!-- next, previous and page info -->
            <apex:commandLink action="{!doPrevious}" rendered="{!hasPrevious}" value="Previous" />
            <apex:outputLabel rendered="{!NOT(hasPrevious)}" value="Previous" />                                  
            <apex:commandLink action="{!doNext}" rendered="{!hasNext}" value="Next" />
            <apex:outputLabel rendered="{!NOT(hasNext)}" value="Next" />
            </apex:pageBlockSection>
            </apex:pageBlockSection>

        </apex:pageBlock>    
        


</apex:form> 

</apex:page>

Thanks

Sudhir