Who to Upate Feild on other graph

Are you wanting to add a new record or update an existing record?

i try this code too,

and success update record,
but if i add code 

.Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr.Contains<TransDeliveryPlanningDAC.orderNbr.FromCurrent»

i got “Object reference not set to an instance of an object”. again

using System;
using System.Collections.Generic;
using System.Collections;
using System.Text;
using PX.Common;
using PX.Data;
using PX.Objects.CM;
using PX.Objects.GL;
using PX.Objects.CS;
using PX.Objects.IN;
using PX.Objects.AP;
using PX.Objects.AR;
using PX.Objects.CR;
using PX.Objects.PM;
using PX.Objects.TX;
using PX.Objects.EP;
using SOOrder = PX.Objects.SO.SOOrder;
using SOLine4 = PX.Objects.SO.SOLine4;
using PX.Objects.SO;
using System.Linq;
using CRLocation = PX.Objects.CR.Standalone.Location;
using SiteStatus = PX.Objects.IN.Overrides.INDocumentRelease.SiteStatus;
using LocationStatus = PX.Objects.IN.Overrides.INDocumentRelease.LocationStatus;
using LotSerialStatus = PX.Objects.IN.Overrides.INDocumentRelease.LotSerialStatus;
using ItemLotSerial = PX.Objects.IN.Overrides.INDocumentRelease.ItemLotSerial;
using SiteLotSerial = PX.Objects.IN.Overrides.INDocumentRelease.SiteLotSerial;
using PX.Objects.AP.MigrationMode;
using PX.Objects.Common;
using PX.CS.Contracts.Interfaces;
using PX.Data.DependencyInjection;
using PX.LicensePolicy;
using PX.TaxProvider;
using PX.Objects.GL.FinPeriods.TableDefinition;
using PX.Objects.GL.FinPeriods;
using PX.Objects.Common.Extensions;
using PX.Objects.PO.LandedCosts;
using System.Runtime.Serialization;
using PX.Data.ReferentialIntegrity.Attributes;
using PX.Objects.Common.Bql;
using PX.Objects.Extensions.CostAccrual;
using PX.Data.BQL.Fluent;
using PX.Data.BQL;
using PX.Data.WorkflowAPI;
using PX.Objects.IN.Services;
using PX.Objects;
using PX.Objects.PO;
using ITDeliveryPlanning;
using static PX.Objects.PO.POOrderEntry_Extension;

namespace PX.Objects.PO
{
    public class POReceiptEntry_Extension : PXGraphExtension<POReceiptEntry>
    {

         #region Event Handlers

        public PXAction<PX.Objects.PO.POReceipt> AddPlanReciept;

        [PXButton(CommitChanges = true)]
        [PXUIField(DisplayName = "Add Plan Reciept")]
        protected IEnumerable addPlanReciept(PXAdapter adapter)
        {
            // Acuminator disable once PX1008 LongOperationDelegateSynchronousExecution [Justification]
            PXLongOperation.StartOperation(this.Base,
             delegate ()
             {

                 var lineplannbr = ItemsPlanning.SelectSingle();

                 var dataform = FormDeliveryPlanReceipt.Current;
                 var a = SelectFrom<ITDeliveryPlanning.ITDeliveryPlanning>
                 .Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr.Contains<TransDeliveryPlanningDAC.orderNbr.FromCurrent>>
                 //And<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr.IsEqual<TransDeliveryPlanningDAC.lineNbr.FromCurrent>.
                 //And<ITDeliveryPlanning.ITDeliveryPlanning.lineReceiptNbr.IsNull>>>
                 .View.Select(Base).TopFirst;

                 var b = SelectFrom<ITDeliveryPlanning.ITDeliveryPlanning>
                   .Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr.IsEqual<TransDeliveryPlanningDAC.orderNbr.FromCurrent>.
                   And<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr.IsEqual<TransDeliveryPlanningDAC.lineNbr.FromCurrent>.
                   And<ITDeliveryPlanning.ITDeliveryPlanning.lineReceiptNbr.IsNull.
                   And<ITDeliveryPlanning.ITDeliveryPlanning.linePlanNbr.IsEqual<TransDeliveryPlanningDAC.linePlanNbr.FromCurrent>>>>>
                   .View.Select(Base).TopFirst;
                 
                 var c = SelectFrom<POReceiptLine>.Where<POReceiptLine.pONbr.IsEqual<TransDeliveryRecieptDAC.orderNbr.FromCurrent>.
                And<POReceiptLine.pOLineNbr.IsEqual<TransDeliveryRecieptDAC.lineNbr.FromCurrent>.
                And<POReceiptLine.receiptNbr.IsEqual<TransDeliveryRecieptDAC.receiptNbr.FromCurrent>>>>
                 .View.Select(Base).TopFirst;
                 try
             {
                     ITDeliveryPlanningMaint graph = PXGraph.CreateInstance<ITDeliveryPlanningMaint>();
                     //if (dataform.LinePlanNbr == null)
                     //{
                         a.ReceiptNbr = dataform.ReceiptNbr;
                         a.LineReceiptNbr = c.LineNbr??12313;
                     graph.DataDeliveryPlanning.Update(a);
                         graph.Save.Press();
                         graph.Save.PressButton();
                         graph.Caches.Clear();
                     //}
                     //else {

                         //b.ReceiptNbr = dataform.ReceiptNbr;
                         //b.LineReceiptNbr = c.LineNbr;
                         //graph.DataDeliveryPlanning.Update(b);
                         //graph.Save.Press();
                         //graph.Save.PressButton();
                         //graph.Caches.Clear();

                     //}
                   

                     this.ViewDeliveryPlaneceipt.Cache.Clear();
                     this.ViewDeliveryPlaneceipt.View.RequestRefresh();
                 }
                 catch (Exception ex)
                 {
                     throw new Exception($"{a.PlaneID}");

                     throw new Exception($"{lineplannbr.PlaneID}"+ex.ToString());

                 }
             });

            return adapter.Get();

        }
        #endregion

        #region Select

        public PXFilter<TransDeliveryRecieptDAC> FormDeliveryPlanReceipt;

        public PXSelect<ITDeliveryPlanning.ITDeliveryPlanning,
            Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr, Equal<Current<TransDeliveryPlanningDAC.orderNbr>>,
            And<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr, Equal<Current<TransDeliveryPlanningDAC.lineNbr>>,
                And<ITDeliveryPlanning.ITDeliveryPlanning.lineReceiptNbr, IsNull>>>> ItemsPlanning;

        public PXSelectReadonly<ITDeliveryPlanning.ITDeliveryPlanning,
            Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr, Equal<Current<TransDeliveryPlanningDAC.orderNbr>>,
            And<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr, Equal<Current<TransDeliveryPlanningDAC.lineNbr>>,
                And<ITDeliveryPlanning.ITDeliveryPlanning.linePlanNbr,Equal<Current<TransDeliveryPlanningDAC.linePlanNbr>>>>>> PlanID;

        public PXSelectReadonly<POReceiptLine,
         Where<POReceiptLine.pONbr, Equal<Current<TransDeliveryRecieptDAC.orderNbr>>,
         And<POReceiptLine.pOLineNbr, Equal<Current<TransDeliveryRecieptDAC.lineNbr>>,
             And<POReceiptLine.receiptNbr,Equal<TransDeliveryRecieptDAC.receiptNbr>>>>> findreceipt;

        public PXSelectReadonly<ITDeliveryPlanning.ITDeliveryPlanning,
            Where<ITDeliveryPlanning.ITDeliveryPlanning.receiptNbr, Equal<Current<POReceipt.receiptNbr>>>> ViewDeliveryPlaneceipt;

        #endregion

        #region Form Dac

        [PXCacheName("TransDeliveryRecieptDAC")]
        public class TransDeliveryRecieptDAC : IBqlTable
        {
            #region PlaneID
            [PXDBIdentity(IsKey = true)]
            [PXUIField(DisplayName = "Plane ID")]
            public virtual int? PlaneID { get; set; }
            public abstract class planeID : PX.Data.BQL.BqlInt.Field<planeID> { }
            #endregion

            #region ReceiptNbr
            [PXString(15, IsUnicode = true,  InputMask = "")]
            [PXUIField(DisplayName = "Receipt Nbr", IsReadOnly = true)]
            [PXDefault(typeof(Search<POReceipt.receiptNbr, Where<POReceipt.receiptNbr, Equal<Current<POReceipt.receiptNbr>>>>), PersistingCheck = PXPersistingCheck.Nothing)]
            public virtual string ReceiptNbr { get; set; }
            public abstract class receiptNbr : PX.Data.BQL.BqlString.Field<receiptNbr> { }
            #endregion

            #region LineReceiptNbr
            [PXString(15, IsUnicode = true, InputMask = "")]
            [PXUIField(DisplayName = "Line Receipt Nbr", Required = true,Visibility = PXUIVisibility.SelectorVisible)]
            [PXSelector(typeof(Search2<POReceiptLine.lineNbr,
                LeftJoin<POReceipt,
                    On<POReceiptLine.receiptNbr, Equal<POReceipt.receiptNbr>>>,
                Where<POReceiptLine.receiptNbr, Equal<Current<POReceipt.receiptNbr>>>>),
            typeof(POReceiptLine.lineNbr), typeof(POReceiptLine.tranDesc), typeof(POReceiptLine.pONbr), typeof(POReceiptLine.pOLineNbr), typeof(POReceiptLine.pOType),
            DescriptionField = typeof(POReceiptLine.tranDesc),
            SubstituteKey = typeof(POReceiptLine.lineNbr),
            SelectorMode = PXSelectorMode.DisplayModeText)]
            public virtual string LineReceiptNbr { get; set; }
            public abstract class lineReceiptNbr : PX.Data.BQL.BqlString.Field<lineReceiptNbr> { }
            #endregion

            #region OrderNbr
            [PXString(15, IsUnicode = true, InputMask = "")]
            [PXUIField(DisplayName = "Order Nbr", Required = true)]
            [PXSelector(typeof(Search5<POReceiptLine.pONbr,
                InnerJoin<ITDeliveryPlanning.ITDeliveryPlanning,
                    On<POReceiptLine.pONbr, Equal<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr>>, 
                    LeftJoin<POReceipt, On<POReceipt.receiptNbr, Equal<POReceiptLine.receiptNbr>>>>,
                Where<ITDeliveryPlanning.ITDeliveryPlanning.lineReceiptNbr, IsNull,
                        And<POReceiptLine.receiptNbr, Equal<Current<receiptNbr>>>>,
                Aggregate<GroupBy<POReceiptLine.pONbr>>>),
                typeof(POReceiptLine.pONbr), typeof(POReceiptLine.vendorID), typeof(POReceipt.vendorID_Vendor_acctName),
            SubstituteKey = typeof(POReceiptLine.pONbr),
            SelectorMode = PXSelectorMode.DisplayModeText)]

            public virtual string OrderNbr { get; set; }
            public string _OrderNbr;
            public abstract class orderNbr : PX.Data.BQL.BqlString.Field<orderNbr> {
            }
            #endregion

            #region LineNbr
            [PXInt()]
            [PXUIField(DisplayName = "PO Line Nbr", Required = true, Visibility = PXUIVisibility.SelectorVisible)]

            [PXSelector(typeof(Search5<POReceiptLine.pOLineNbr,
                InnerJoin<ITDeliveryPlanning.ITDeliveryPlanning,
                    On<POReceiptLine.pONbr, Equal<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr>,
                        And<POReceiptLine.pOLineNbr, Equal<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr>>>>,
                Where<ITDeliveryPlanning.ITDeliveryPlanning.lineReceiptNbr, IsNull,
                    And<POReceiptLine.pONbr, Equal<Current<orderNbr>>,
                        And<POReceiptLine.receiptNbr,Equal<Current<receiptNbr>>>>>,
                Aggregate<GroupBy<POReceiptLine.pOLineNbr>>>),
             typeof(POReceiptLine.tranDesc), typeof(POReceiptLine.pOLineNbr), typeof(POReceiptLine.lineNbr),
            DescriptionField = typeof(POReceiptLine.tranDesc),
            SubstituteKey = typeof(POReceiptLine.pOLineNbr),
            SelectorMode = PXSelectorMode.DisplayModeText, DirtyRead = true)]
            public virtual int? LineNbr { get; set; }
            public abstract class lineNbr : PX.Data.BQL.BqlInt.Field<lineNbr> { }
            #endregion

            #region LinePlanNbr
            [PXInt()]
            [PXUIField(DisplayName = "Delivery To", Required = true)]
            [PXSelector(typeof(Search<ITDeliveryPlanning.ITDeliveryPlanning.linePlanNbr,Where<ITDeliveryPlanning.ITDeliveryPlanning.orderNbr, 
                Equal<Current<orderNbr>>,
                And<ITDeliveryPlanning.ITDeliveryPlanning.lineNbr,
                    Equal<Current<lineNbr>>>>>),
            SubstituteKey = typeof(ITDeliveryPlanning.ITDeliveryPlanning.linePlanNbr),
            SelectorMode = PXSelectorMode.DisplayModeText, DirtyRead = true)]
            public virtual int? LinePlanNbr
            {
                get; set;

            }
            public abstract class linePlanNbr : PX.Data.BQL.BqlInt.Field<linePlanNbr> { }
            #endregion

            #region PlanDate
            [PXDate()]
            [PXUIField(DisplayName = "Plan Date", IsReadOnly = true)]
            public virtual DateTime? PlanDate { get; set; }
            public abstract class planDate : PX.Data.BQL.BqlDateTime.Field<planDate> { }
            #endregion

            #region ConfirmDate
            [PXDate()]
            [PXUIField(DisplayName = "Confirm Date", IsReadOnly = true)]
            public virtual DateTime? ConfirmDate { get; set; }
            public abstract class confirmDate : PX.Data.BQL.BqlDateTime.Field<confirmDate> { }
            #endregion

            #region DeliveryDate
            [PXDate()]
            [PXUIField(DisplayName = "Delivery Date", IsReadOnly = true)]
            public virtual DateTime? DeliveryDate { get; set; }
            public abstract class deliveryDate : PX.Data.BQL.BqlDateTime.Field<deliveryDate> { }
            #endregion

            #region QtyPlan
            [PXDBDecimal()]
            [PXUIField(DisplayName = "Qty Plan")]
            public virtual Decimal? QtyPlan { get; set; }
            public abstract class qtyPlan : PX.Data.BQL.BqlDecimal.Field<qtyPlan> { }
            #endregion

            #region GroupPlanDescription
            [PXString(225, InputMask = "")]
            [PXUIField(DisplayName = "Group Plan", IsReadOnly = true)]
            public virtual string GroupPlanDescription { get; set; }
            public abstract class groupPlanDescription : PX.Data.BQL.BqlString.Field<groupPlanDescription> { }
            #endregion

            #region GroupDeliveryDescription
            [PXString(225, InputMask = "")]
            [PXUIField(DisplayName = "Group Delivery", IsReadOnly = true)]
            public virtual string GroupDeliveryDescription { get; set; }
            public abstract class groupDeliveryDescription : PX.Data.BQL.BqlString.Field<groupDeliveryDescription> { }
            #endregion

            #region GroupItemDescription
            [PXString(255, InputMask = "")]
            [PXUIField(DisplayName = "Group Item")]
            public virtual string GroupItemDescription { get; set; }
            public abstract class groupItemDescription : PX.Data.BQL.BqlString.Field<groupItemDescription> { }
            #endregion

            #region StatusPlan
            [PXInt()]
            [PXDefault(2, PersistingCheck = PXPersistingCheck.Nothing)]
            [PXIntList(new int[] { 1, 2, 3 }, new string[] { "Unprocessed", "On Going", "Complete" })]
            [PXUIField(DisplayName = "Status Plan")]
            public virtual int? StatusPlan { get; set; }
            public abstract class statusPlan : PX.Data.BQL.BqlInt.Field<statusPlan> { }
            #endregion
        }
        #endregion

    }
}

You should turn on debugging and step through the code in Visual Studio. Pause the code before you get to the line with the errors and check the state and value of your variables. You haven’t initialized something in the statement that you’re having the problem with.