Runtime error while AttachPathAndPropagateNotifications()

Question

Hi!
I am trying for "replace <column>" expression in a "Derived Column" transformation operator(programatically).
Before this, I tried this through SSIS Business Intelligent Studio and it worked! So, I moved towards programatical approach.
In my program, while connecting Derived Column with the FlatFileDestination, I am getting run time error:
{"Exception from HRESULT: 0xC004705F"}
at AttachPathAndPropagateNotifications()
// Map a path between the transformation component to the FlatFileDestination  
            try  
                this.dataFlowTask.PathCollection.New().AttachPathAndPropagateNotifications(  
                    this.TransformationDataFlowComponent.OutputCollection[0], this.DestinationDataFlowComponent.InputCollection[0]);  
            catch (Exception e)  
                System.Console.WriteLine(e.Message);  
My Expression is:(mm/dd/yyyy)
SUBSTRING(purchase_date,4,2)+"/"+SUBSTRING(purchase_date,1,2)+"/"+SUBSTRING(purchase_date,7,4)
And my transformation component code is:
public IDTSComponentMetaData90 AddDerivedColumn(ref MainPipe dataFlowTask, ref IDTSComponentMetaData90 sourceDataFlowComponent)  
            //Note that MainPipe and IDTSComponentMetaData are passed as references  
            // Add the component to the DataFlow task.  
            this.addderivedcolumn = dataFlowTask.ComponentMetaDataCollection.New();  
            // Set component's stock properties.  
            this.addderivedcolumn.ComponentClassID = "DTSTransform.DerivedColumn";  
            this.addderivedcolumn.Name = "DerivedColumn";  
            this.addderivedcolumn.Description = "Adds a derived column";  
            CManagedComponentWrapper instance = this.addderivedcolumn.Instantiate();  
            instance.ProvideComponentProperties();  
            // Attach path between the flat file source components output, and the Sort Component's Input.  
            dataFlowTask.PathCollection.New().AttachPathAndPropagateNotifications(  
                sourceDataFlowComponent.OutputCollection[0], this.addderivedcolumn.InputCollection[0]);  
            this.addderivedcolumn.InputCollection[0].ExternalMetadataColumnCollection.IsUsed = false;  
            this.addderivedcolumn.InputCollection[0].HasSideEffects = false;  
            IDTSVirtualInput90 vInput = this.addderivedcolumn.InputCollection[0].GetVirtualInput();  
            foreach (IDTSVirtualInputColumn90 vColumn in vInput.VirtualInputColumnCollection)  
                //get a handle into the input column and specify the transformation  
                if (vColumn.Name == DateTimeColumnName)  
                    IDTSInputColumn90 col = instance.SetUsageType(addderivedcolumn.InputCollection[0].ID, vInput, vColumn.LineageID, DTSUsageType.UT_READWRITE);  
                    col.Name = vColumn.Name;  
                    IDTSCustomProperty90 Property = col.CustomPropertyCollection["Expression"];  
                    Property.Value = GetExpressionString(DateTimeFormat, DateTimeColumnName);  
                    Property = col.CustomPropertyCollection["FriendlyExpression"];  
                    Property.Value = GetExpressionString(DateTimeFormat, DateTimeColumnName);  
            this.addderivedcolumn.OutputCollection[0].TruncationRowDisposition = DTSRowDisposition.RD_FailComponent;// RD_NotUsed;  
            this.addderivedcolumn.OutputCollection[0].ErrorRowDisposition = DTSRowDisposition.RD_FailComponent;// RD_NotUsed;  
            return this.addderivedcolumn;  
Please suggest a solution/way to handle such type of situation.
What is a correct way of connecting between transformation component and destination component?
When I see in BIDS, Derived Column OutputColumn Collection Count is 0. So, I wonder, how is it passing the output to destination component?
Regards,
Mandar.Developer

Answer 1

Hi,
I am getting error while trying add path between two derived columns components at "AttachPathAndPropagateNotifications" method. 
Here, dcMetada is existing Derived Column component and I am creating another Derived Column component - dcDataConversion.
And while creating path between these two, getting exception.