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


Post New Web Links

using objectdatasource with entity model leads to System.ObjectDisposedException

Posted By:      Posted Date: October 03, 2010    Points: 0   Category :.NET Framework
 

hi every body.

i my web application i used entity data model and imported some select stored procedures as functions (Add Function Import). so i used objectdatasource to call this functions and set their parameters to retrieve data. but when i run application the following exception shows:

The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

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.ObjectDisposedException: The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


View Complete Post


More Related Resource Links

using objectdatasource with entity model

  

hi every body.

i my web application i used entity data model and imported some select stored procedures as functions (Add Function Import). so i used objectdatasource to call this functions and set their parameters to retrieve data. but when i run application the following exception shows:

 i just selected objectdatasource select command and assinged it to dropdownlist datasource

The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

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.ObjectDisposedException: The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

Binding WPF Controls to an Entity Data Model

  
In this interview, programming writer, McLean Schofield, demonstrates how to bind WPF controls to an entity data model, using Visual Studio 2010 Beta 1. You can also learn more in the topic: Walkthrough: Binding WPF Controls to an Entity Data Model.

Binding WPF Controls to an Entity Data Model

  
In this interview, programming writer, McLean Schofield, demonstrates how to bind WPF controls to an entity data model, using Visual Studio 2010 Beta 1. You can also learn more in the topic: Walkthrough: Binding WPF Controls to an Entity Data Model.

Data Points: Designing an Entity Data Model

  

With the Entity Framework, developers are given more flexibility by being able to design around a conceptual model rather than a relational data model. To get started, you need to know how to design an Entity Data Model. John Papa walks you through that process.

John Papa

MSDN Magazine February 2008


Entity Data Model and database view returning the same columns as there are in a table

  

When adding a stored procedure into the Entity Data Model I can select whether the procedure returns a scalar, a (new) complex type or one of the entity types I already defined. 

How do I do something similar for a view?


I mean assuming I have a view like this

CREATE VIEW FilteredFoos as SELECT Foo.* FROM Foo join ... WHERE ...

(that is a view that implements some involved filtering, but returns all columns from one table) how do I add it to the project so that I can use the entity set, but get the Foo objects, not some new FilteredFoo objects.


var foos = myDB.FilteredFoos.Include("Bar").ToList();

foreach (Foo foo in foos) { ...


Thanks, Jenda


using stored procedures in ado.net entity framework model

  
Hi, I have a issue, i am calling stored procedure through entity model like result=ctx.spname(parmas), i am expecting 0 or 1 as a result after the execution of sp, but its returning unknown values like 178 for number records. Please suggest what went wrong Thanks

Entity Model- Add Function Import - selected stored procedure returns no columns

  
I am using stored procedures returns columns from pivot table generated dynamically "Execute (@PivotTableSQL)".So the resultset columns cannot be identified. Please let us know how to add function import and Get Column information(create complex Type). Thanks in advance. My stored procedure is alter PROCEDURE spGetQuestGrid( @QID as int)ASBEGIN SET NOCOUNT OFF SET FMTONLY OFF  Declare @optId varchar(10) set @optId = (select DISTINCT Optid from  QuestOptions where  QID = @QID)    DECLARE @PivotColumnHeaders VARCHAR(MAX) SELECT @PivotColumnHeaders =  COALESCE(@PivotColumnHeaders + ', [' + cast(Caption as varchar) + ']' ,  '[' + cast(Caption as varchar)+ ']' ) FROM OptionsDetail where OptId = @optId  DECLARE @PivotTableSQL NVARCHAR(MAX)  SET @PivotTableSQL = 'select * from  ( select  Caption,Optid  from OptionsDetail ) as dt PIVOT  ( min(Optid) FOR Caption IN ( '+ @PivotColumnHeaders + '))as pt'     Execute (@PivotTableSQL)  END 

Can I create an ADO.NET Entity Data Model for a MySQL database using Visual Web Express 2010?

  

Can I create  an  ADO.NET Entity Data Model for a MySQL database using Visual Web Express 2010?

If yes, are there any documentation or tutorials?

Thanks.


How do you create a ADO.NET Entity Data Model for a MySQL database using Visual Web Express 2010?

  
 

Can I create a ADO.Net Entity Data Model for a MySql(5.0.1) Database using a Visual Web Express 2010? If yes, can anyone please let me know how to do this.


entity data model

  

hi.

in every table's table adapter i had added 4 storedprocedures(CRUD), then i could call this procedures from objectdatasource select,update,insert and delete commands and assign parameters to session objects;

now i moved from dataset to entity framework model.

i want to now how assign a select command to entitydatasource or objectdatasource from imported functions in my entity data model?

 

tanks.


get data from entity model in rest service

  

Hi,

I created a rest service and a database in entity model (edmx)..

i want to retrieve data from database and show it in client using a rest service...

 

is it valid to store like

c1 =

 

Convert.ToInt32(context.ExecuteStoreQuery<string>(

How to update Domain Service from Entity Data Model?

  

Hi guys,

So I'm using Entity data model to reflect my database and I generate Domain service from my Entity data model.

I understand that if I have changes in my database, I can just choose "Update Model from Database", but there is no "Update Domain service from Model" option available.

How should maintain my domain service? I'm not going to delete away it and regenerate it whenever there are some changes, right?

I need to know what if

- I add in new table in my database, how should I update from database-->model-->domain service?

- I add in new fields in my table, how should I update from database-->model-->domain service?

Thanks.


C# SerialPort System.ObjectDisposedException, safe handle has been closed in System.DLL

  

I have an application in which at start up I need to do a port discovery process to determine whether instruments are attached to the end of any number of PC com ports. These com ports could be Bluetooth enumerated or, using FTDI USB to serial line convertor drivers, a USB connection. At start up I determine which ports are being used for this session by interogating all the ports stored in a list. I do this by opeing the port and then using a synchronous write and read (using timeouts of 500ms). I put try and catch around the port open to capture the case where the port has been disconnected (USB) or is not currently accessible (Bluetooth) and create a list of instrument objects each of which will have its own serial port object. Before going into normal mode I close the ports. So in essence this is

foreach(string portname in portstouselist)

    if open port success

        if writeline(Instrument?) success

            if Readline success

                 add instrument found and associated port to list

       close port

Normal running operates something like a data logger so I open each of the ports to which I have an instrument connected and start an asynchronous read with an associated data received event handler and infinite time out.

It is possible that the user connections could change during the application run.

System.ObjectDisposedException: Cannot access a disposed object.Object name: 'MQCacheableInfo'.

  

Hi,

I am using MSMQ concept in my .Net windows service application. So, i got below mentioned error and messages are moved to UnHandled queue. If i process manually then message has been processed well. So, this issue we got quite common on my production environment. I would like to know whether can we fix this issue.

Exception Message:

2010-10-05 01:37:03,687 [Handler.1] WARN  HandlerService.CWorkerThread - Couldn't process message

System.ObjectDisposedException: Cannot access a disposed object.Object name: 'MQCacheableInfo'.

   at System.Messaging.MessageQueue.MQCacheableInfo.get_WriteHandle()

   at System.Messaging.MessageQueue.StaleSafeSendMessage(MQPROPS properties, IntPtr transaction)

Populate entity data model from database

  

I've been using entity data models for quite a few sections of my website and find it really good for saving things to the database.

After searching for a while, I can't seem to find a good way to populate a new instance with data from a database other than using a data reader. E.G:


MyClass.myID = reader("myID")


Am I missing something?


MVVM and Entity Framework - where is the Model part?

  

Hi,

I am using Entity Framework to connect to MS SQL (Azure). I have a WPF application, and I am using MVVM. But...where is my Model layer? Right now I have made the 'traditional' Model layer, which then translates the Entity Framework into new objects. That works, - but I am missing out of all the implicit benefit of Entity Framework! If I pulled a collection directly from the Entity Framework to the the ViewModel, I could then work on the collection (add, delete, update) and then just run SaveChanges() on the connection and it was a done deal. But right now it is the object in the Model layer that I work on, and then in this object I have to add, delete or update another object in the database through Entity Framework.

To get the benefits, should I just skip all the extra objects in my Model layer and make the Entity Framework a part of the Model Layer (although it is also a data access layer, of sorts)? Or is there a way to pass the Entity Framework objects through the Model layer smoothly so I still maintain the wonderful SaveChanges() functionality?

Thanks!

//Anders 


How use sum in Entity Data Model with linq?

  

hi

i have a database with 4 table aspnet_Users, Forum, Topic, Post thay are related:

aspnet_Users with Topic by UserId

Forum with Topic by ForumId

Topic with Post by TopicId

i created a linq to get data from Database like:

Dim db As New MelorinEntities()
        Dim Topics = From t In db.Topic _
                     Join u In db.aspnet_Users _
                     On t.UserId Equals u.UserId _
                     Where t.ForumId = _ForumId _
                     Select t.UserId, t.TopicId, t.Name, t.IsLock, t.NumberOfView, _
                     u.UserName


 

 now i need to get also how meny post are in a topic but i don't know how to write the querry

can you please help me?

thanks

 


Categories: 
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