.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
david stephan
Gaurav Pal
Post New Web Links

Object per workflow instance via Extension

Posted By:      Posted Date: October 02, 2010    Points: 0   Category :Windows Application

I have been trying unsuccessfully to create an extension that will allow me to supply a new instance of a object to each workflow instance.  Specifically, I am attempting to supply a variant of the UnitOfWork class used to managed long running NHibernate ISsessions.  I keep hearing that you can add a service behavior extension on a per-workflow instance basis, but none of the examples I’ve seen show you how.  When I attempt to retrieve the extension in my Activity, I always get the same singleton instance.


public class UnitOfWork : IUnitOfWork


        public Dictionary<string, ISessionFactory&

View Complete Post

More Related Resource Links

Can I dehydrate the Workflow object as well as the instance?

Hiya All Can I dehydrate the workflow object (i.e. not an instanciation of it) into SQLServer?  I want to save all versions created of a workflow so that I can chose to instanciate the workflow from any of the previous versions if I need to. This is due to a compliancy issue - being able to reconstruct the data created by a previous version of a workflow to prove accuracy. ThanksMichelle x

Sharepoint Workflow - Object Reference Not Set to an instance of an object



I create a Custom Sharepoint workflow using VS 2008. Let me go step by step:

1. I have an infopath form which is a requisition form.  I saved all my infppath source class and other custon class files in a Class library.

2. I built this class library and assigned a string key to it.

3. created a custom sequential workflow and added my class library dll to this workflow.

4. In my workflow I have a function where I am using :

                    using (SPSite currentSite = new SPSite(siteURL))
                        using (SPWeb currentWeb = currentSite.OpenWeb())

Extension instance management for workflow service


I have written some custom activities for business validation (http://www.neovolve.com/post/2010/10/13/Custom-Workflow-activity-for-business-failure-evaluatione28093Wrap-up.aspx with project source at http://neovolve.codeplex.com/SourceControl/changeset/view/68064#1422354). They have worked fine until I use them in a workflow service.

The evaluator activity pushes a business failure into a custom extension. The custom extension will then detect whether the evaluator is contained in a scope activity. If there is a scope activity, it will store the failure in the extension for the scope to collect later. If there isn't a scope, it will throw an exception straight away. The scope will look for failures in the extension written by its child activities when it completes and will throw an exception for the set of failures.

This has worked fine so far for workflows executed via WorkflowInvoker and WorkflowApplication. There are unit tests for these activities to ensure that the above behavior is working as expected.

I have just used these activities in a workflow service and found that the extension behavior is very different. The function p

Visual Studio 2005 Extension for Sharepoint Workflow.


Hi All,

I want to develop sequential workflow using visual studio 2005. I have development server with Windows Server 2003 x86 installed.

Could anyone advise will i need to install Sharepoint first to have workflow feature in visual studio.

Also what all extension component i need to install to develop Sequential Workflow for Sharepoint 2007 document library.


Many Thanks


-- Regards Sandeep

VS2010 Silverlight 4 - Getting "Object reference not set to an instance of an object" when loading a

In Visual Studio 2010 I'm trying to use the Blacklight Controls (http://blacklight.codeplex.com/releases/view/37652) in my own project (and actually included the Blacklight.Controls project in my solution so that I could debug what was going on) and... after making all the XAML changes needed to incorporate the Blacklight navigation menu with my stuff in the innermost grid... everything compiled ok when doing a Build.  When I run it there's a reference to a resource dictionary in the XAML that fails with the object reference error above.  The XAML is as follows:       <UserControl.Resources>       <controls:ResourceDictionaryManager x:Key="ResourceDictionaryManager">       <controls:ResourceDictionaryManager.ResourceDictionaries>       <controls:ResourceDictionaryCollection>       <controls:ResourceDictionary Path="/Blacklight.Showcase;component/ResourceDictionaries/DavesGlossyControls.xaml">       <controls:ResourceDictionary.ResourceKeys>       <controls:ResourceKeyCollection>       <controls:ResourceKey ResourceName="GlossyBlackScrollViewer" />       </controls:ResourceKeyCollection>     &

Is there a way to check if workflow instance already exists for a particular productID in Workflow o

I am using Visual Studio 2008 and .NET 3.5. I am trying to build a WF that is exposed as WCF hosted on IIS. This service is consumed by ASP.NET client. It is a very simple WF- receive info for new product "A"- send email to person 'Xyz' that new prodcut "A" is received- do some business process for product "A"- send out more notifications for product "A"Consider this scenario - - Client hits submit on asp.net page for prodcut "A"- new WF instance is created for product "A"- client can go back to the same page, edit some more info and hit save again. However, this time or for any subsequent "Saves",  I do not want to create a new WF instance for product "A".I can check to see if a WF instance exists for product "A" on the client side before calling the service operation. However, I want to see if there is a way to do this in WF or WorkflowServiceHost, as I don't want to add this logic to client. First acitvity in WF has to be receive activity with CanCreateInstance = true, so not sure how I can do this check in WF itself.Also, I have another stupid question, when using WF exposed as WCF service, do we have to implement all service operations using WF? What if I have some service operations that just involves checking some business logic? Do I implement this in a

System.InvalidOperationException: Instance operation is not valid on workflow runtime thread

Am getting the exception related in the title of this article when using the StateMachineWorkflowInstance object to arbitarily set state in my workflow code; and am unsure why.  The code follows below:   500     Protected Overrides Function Execute(ByVal executionContext As System.Workflow.ComponentModel.ActivityExecutionContext) As System.Workflow.ComponentModel.ActivityExecutionStatus   501    502    506         Dim smwi As StateMachineWorkflowInstance = New StateMachineWorkflowInstance(StaticWFRuntime.LocalRuntime, Me.WorkflowInstanceId)   511    512         'set workflow-wide database connection string   513         _connectionString = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString   518    519         Utility.LogEnabled()   520    521         Utility.FoaeaLogger.WriteEntry("Processing TracingApplication.Execute()....", EventLogEntryType.Information)   522         If StaticWFRuntime.LocalRuntime Is Nothing OrElse StaticWFRuntime.LocalRuntime.IsStarted = False Then   523             Utility.FoaeaLogger.WriteEntry("No static RuntimeService object exists!", EventLogEntryType.Warning)   524         End If   525    526         Return MyBase.Execute(executionContext)   527    528     End Function   796     Private Sub gotoState2_ExecuteCode(ByVal sender As System.Object, ByVal e As System.EventArgs)   797    798        

reference not set to an instance of an object.

Hi friends,I got this error. This application for  delete  multiple record in gridview using Check Box.Please verify it. I tried before one application, that one finally worked,That application also error occurred, but after some time it execute(automatic I didnt do anything) correctly,Please tell me why this type of error occurred.  Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.Source Error: Line 153: if (chkdelete != null) Line 154: { Line 155: chkall.Checked = array.Contains(grideviewsasmple.DataKeys[i].Value); Line 156: Line 157: if (!chkdelete.Checked) Source File: c:\Inetpub\wwwroot\AdditionUpdate\Default.aspx.cs    Line: 155

Object Reference not set to an instance of an object

Hi All,While using listview to upload images I get the error message. "Object Reference not set to an instance of an object".Gallery.aspx is suppose to call ManagePhotoAlbum.aspxError generatedLine 5: Protected Sub LinqDataSource1_Inserted(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LinqDataSourceStatusEventArgs) Handles LinqDataSource1.Inserted Line 6: Dim myPhotoAlbum As PhotoAlbum = CType(e.Result, PhotoAlbum) Line 7: Response.Redirect(String.Format("ManagePhotoAlbum.aspx?PhotoAlbumId={0}", _ Line 8: myPhotoAlbum.Id.ToString())) Line 9: End SubCode Behind Gallery.aspx.vbPartial Class Photo_Gallery    Inherits System.Web.UI.Page    Protected Sub LinqDataSource1_Inserted(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LinqDataSourceStatusEventArgs) Handles LinqDataSource1.Inserted        Dim myPhotoAlbum As PhotoAlbum = CType(e.Result, PhotoAlbum)        Response.Redirect(String.Format("ManagePhotoAlbum.aspx?PhotoAlbumId={0}", _            myPhotoAlbum.Id.ToString()))    End Sub    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load    End S

Object reference not set to an instance of an object.

This one has been killing me for 2 days now, and it should be so simple.I have a button on a page with an onClick that calls a web service.  I get the above error (on Line 938, Sys.WebForms.PageRequestManagerServerErrorException) as soon as the button is clicked.  The error seems to occur the second that the service is called - I have verified that every step of  the client-side code works and does not contain null values.  When remote debugging, the exception hits as soon as it jumps over to the web service's source code, an indication that the reference to the server itself is also valid.The code: (bad spelling and formatting not mine... I inherited this and have been cleaning it up as I go)'btnClick event - removed the log-writing lines for clarity's sake Private Sub btnSendCIS_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSendCIS.Click Dim dt As DataTable Dim retr As String = "" dt = createOrderTable() Dim client As New ProdEndpoints.CISPRODUCTIONClient() retr = client.CompleteOrders(dt) client.Close() tmRecive.Interval = tickinterval getallrecive() End Sub 'createOrderTable - creates the dt that is sent to the service, also with log-writing lines removed. verified this is not returned Null as the log-writing includes pulling ou

Null Reference Exception was not handled by user Object Reference not set to instance of an object

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Security.Principal;using System.Data;using System.Data.SqlClient;using System.Windows;using System.Collections; public partial class Default2 : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {     }    private bool tableCopied = false;    private DataTable originalDataTable;     protected void GridView2_RowDataBound(object sender, GridViewRowEventArgs e)    {         if (e.Row.RowType == DataControlRowType.DataRow)        {            //string sValue = e.Row.Cells[3].Text;             if (!tableCopied)            {                originalDataTable = ((System.Data.DataRowView)e.Row.DataItem).Row.Table.Copy();                ViewState["originalDataTable"] = originalDataTable;      &nbs

Object reference not set to an instance of an object.

can anybody help me with this error??the error occurs in the first line of the if statement...i really dont know how to fix this problem.. please help..Dim GW1 As new GridView            GW1 = CType(Me.LoginView1.FindControl("GridView1"), GridView)            If GW1.PageCount < 1 Then                lblFromDept.Visible = True                ddlFromDept.Visible = True                SelectedFromDept.Visible = False                btnOK.Visible = True            Else                lblFromDept.Visible = False                ddlFromDept.Visible = False                SelectedFromDept.Visible = False                btn

Object reference not set to an instance of an object.

When  can debugg the code it will give the error "Object reference not set to an instance of an object.". The code is--     using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using SMC.AlphaAccounting.EntryControls; using SMC.AlphaAccounting.PlugIns; using SMC.PlugInContracts; using SMC.BusinessObjects; using SMC.Utils; using SMC; using SMC.AlphaAccounting; using SMC.AlphaAccounting.DataEntry; using Infragistics.Win.UltraWinEditors; using Infragistics.Win.UltraWinMaskedEdit; using Infragistics.Win.UltraWinToolbars; namespace WindowsApplication3 {     public partial class FormCountry : SmcDataEntry     {         private boGlChart boLocalGlChart;         private boVendors boLocalVendors;         public FormCountry()         {             InitializeComponent();             this.ultraNumericUniqueID.KeyDown += new KeyEventHandler(ultraNumericUniqueID_KeyDown);             this.ultraNumericUniqueID.KeyPress &

Workflow Instance ID field in MS Access

Hello, please help! When I open a SP list with MS Access (Action > Open with Access), the Workflow Instance ID field is available with no data.  How can I get this field to display so I can create queries within MS Access using joins/relationships?  Thank you!

Object reference not set to an instance of an object.

Protected Sub CreateUserWizard1_CreatedUser(ByVal sender As Object, ByVal e As System.EventArgs)         Dim CUW1 As New CreateUserWizard         CUW1 = CType(Me.LoginView1.FindControl("CreateUserWizard1"), CreateUserWizard)         Dim p As ProfileCommon = DirectCast(ProfileCommon.Create(CUW1.UserName, True), ProfileCommon)         p.SelectFromDept = DirectCast(CUW1.CreateUserStep.ContentTemplateContainer.FindControl("ddlSelectFromDept"), DropDownList).SelectedValue         p.Save()     End Subanybody can help me with this error?? that error occurs in the p.SelectFromDept line...Protected Sub CreateUserWizard1_CreatedUser(ByVal sender As Object, ByVal e As System.EventArgs)        Dim CUW1 As New CreateUserWizard        CUW1 = CType(Me.LoginView1.FindControl("CreateUserWizard1"), CreateUserWizard)        Dim p As ProfileCommon = DirectCast(ProfileCommon.Create(CUW1.UserName, True), ProfileCommon)        p.SelectFromDept = DirectCast(CUW1.CreateUserStep.ContentTemplateContainer.FindControl("ddlSelectFromDept"), DropDownList).SelectedValue        p.Save()    End S

Session Object not set to an instance.....

Hello all, Please tell me if I have made a mistake in the following code. It is part of a class that cycles through various conditions to return a value to aspx page. I get null exception when it hits the session variable. I even declared the session variable in global.asax, and thought that I was checking for null value correctly. Obviously I haven'tImports Microsoft.VisualBasic Imports System.Linq Imports System.Web Imports System.Web.Services Imports System.Web.HttpContext Public Class OrderNumber Public Shared Function GetOrderNumber() As String ' ''//Sets OrderNumber if it exists If Not HttpContext.Current.Request.QueryString("OrderNumber") Is Nothing Then Return CType(HttpContext.Current.Request.QueryString("OrderNumber"), String) ElseIf Not HttpContext.Current.Session("OrderNumber") Is Nothing Then Return CType(HttpContext.Current.Session("OrderNumber"), String) ElseIf Not FindExistingOrder() Is Nothing Then Return FindExistingOrder() Else : Return "" End If End Function   Thanks, I am pretty well stumped. Have a good evening.

"Object reference not set to an instance of an object."

Working in Visual Web Developer 2008 Express Edition, attempting to configure data source (SqlDataSource),  able to include server name: (local)\sqlexpress and the "Test Connection" is successful.  However, when I try to make a new database (or load one of the samples), I keep getting an alert: "Object reference not set to an instance of an object."  I've posted in this forum under "Data Access: Sql Server, Sql Server Express..." with a response to remove and then reinstall VWD and SQL Express.  Thus, I've removed and reinstalled Sql Server 2008.  I tried to remove then reinstall VWD 2008 Express with "Windows Install Clean Up" and "Add / Remove Programs", but in Add/ Remove Programs, it just tried to reinstall without removing then stopped halfway and prompted me to insert a disc (which I don't have since it was an online download).  Not sure what is going on behind the scenes.  Don't know what the problem is as this was never an issue in VWD 2005 Express Edition. Does the problem involve Visual Web Developer 2008 Express Edition or SQL Server 2008?  Any suggestions on removing and then reinstalling VWD 2008 Express?  I feel like I'm missing something simple but after 3 days I'm getting nowhere... As always, help is much appreciated and tha
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend