ASP.NET 3.5 Extensions Preview

ASP.NET and Entity Data Framework - Best Practices?

digitalactive — Wed, 11 Feb 2009 22:49:38 GMT

I'm looking for some advice regarding using EDF and ASP.NET. My main concern is the use of contexts within my code. What is the best way to handle contexts? Currently I'm getting the dreaded error: "An entity object cannot be referenced by multiple instances of IEntityChangeTracker."

What's the best way to ensure I'm using the same context? What are the implications for leaving a context 'open' in the Session? Is this a big 'no no' ?

How can I achieve a consistent approach (without having to pass context parameters all over the place) and yet keep my application scalable?

Thanks,

Simon.

Autocomplete ajax without calling a service

ronald_yoh — Tue, 08 Dec 2009 09:56:01 GMT

Hi,

is there a way to implement ajax autocomplete without calling a service but calling a server-side method only? if any, can you please give an example?

thanks

Advantages of LINQ?

jeyaseelan@ajsquare.net — Sat, 22 Mar 2008 12:55:02 GMT

May i know what are the main advantages using LINQ over SQL management studio?

Strange runtime error with SP1

Ricardojb — Sun, 21 Sep 2008 22:09:20 GMT

I have installed SP1 on my development machine, but my host company still is testing it.

I thought it shouldn't be a problem because I wasn't going to use any SP1 features until they installed SP1.

And that was true, until I got an annoying error.

I have a very simple page which is using an ObjectDataSource, for some reason, some times Visual Studio gets rid of the insert or update method.

Anyway, I added the Insert Method again to the ObjectDataSource and then I couldn't longer access that page.

MissingMethodException: Method not found: 'Void System.Web.UI.WebControls.Parameter.set_DbType(System.Data.DbType)'.]

Ok, I could understand that there could be an incompatibility between SP1 and RTM, what I can't get is that the page was working fine before (except for the Insert method) and I have a lot of pages using different ObjectDataSource, most of them basically with the same architecture and I don't have any problem.

I tried copying the website instead of publishing but it did not work either.

I have googled the error to not avail, I only found a post in the Discount.asp forum, with the same error but no solution.

Again, I can wait until they deploy SP1, but it puzzles me that other pages with the same controls and settings have no problems.

For what I could read, apparently the problem is with pre-compiled dlls, my dal is in a separate .dll so I compiled it on my local machine and then it's added to the bin folder, but as I said, there isn't anything in the page that causes the error or the DAL different than other areas, only that this one is actually simpler.

find a row index in datagrid of silverlight

wgg117 — Thu, 12 Nov 2009 21:35:15 GMT

I have a SelectionChanged event on a combobox in a datagrid. when it fires i need to find out the row number or index of that row where this combobox resides.. How can I do that ?

Thanks

Question about security and the Entity Framework

netplan — Fri, 06 Nov 2009 23:36:22 GMT

Hi,

I'm new to the Entity Framework and I have a question about the benefits of EF.

I've always thought that the most secure way to access data from the database was to use stored procs and assign execute permissions to these procs and never assign permissions at the table level...but with EF...this is the way it's done. Are there any issues with doing it this way?

Is the Entity Framework really the way to go? Are there any downfalls to using EF?

Thanks

Drag and Drop in ASP.NET 3.5

abuswell — Tue, 20 May 2008 21:34:16 GMT

Are the drag and drop scripts (previewDragAndDrop.js, etc.) from the AJAX Futures included somewhere in the 3.5 extensions preview? If so, what are they called and what needs to be included in a Web Application to use them?

Thanks

Entity framework now or later?

dan_abdn — Fri, 04 Sep 2009 10:14:32 GMT

Hello everyone,

I've just watched a vid on Entity Framework 3.5 and it looks fab.

However, I've also seen that Entity Framework 4.0 has some interesting enhancements.

I'm going to be creating suite of applications and I just wondered....

1. What happens if I start with EF 3.5 SP1 and in a few months get EF 4.0 when (.NET 4.0 and VS2010 is released?) - what will be the steps involved in upgrading? Any breaking changes likely? - I realise this is a little early to be asking this question, but I'm hoping someone wise beyond their years will lend some nice advice.

2. Should I just wait for EF4.0 i.e. because major code changes will be required?

3. When is VS2010 and .NET 4.0 likely to be released (no clever comments like "twice the time that it took to finish half of it") :)

Many thanks,

Cheerio.

Dan.

Cannot add ADO.NET Entity Data Model to web application project

mike.j.pappas — Mon, 10 Dec 2007 18:06:57 GMT

I have Visual Studio 2008 RTM installed as well as the 3.5 Extensions Preview. I have created a new project using the ASP.NET 3.5 Exteniosn Web Application template. When I try to add a new ADO.NET Entity Data Model (edmx) I cannot seem to find it in the list of possible items to add. The only item template remotely close to it is "ADO.NET Data Service."

How do I get this to show up in my template list?

Using NumericUpDownExtender, but texbox does not display

AppDevForMe — Sun, 01 Nov 2009 06:33:21 GMT

<%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="cc1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <asp:TextBox ID="TextBox1" runat="server" Width="60px"></asp:TextBox>
        <cc1:NumericUpDownExtender ID="TextBox1_NumericUpDownExtender" runat="server"
            Enabled="True" Maximum="1.7976931348623157E+308"
            Minimum="-1.7976931348623157E+308" RefValues="" ServiceDownMethod=""
            ServiceDownPath="" ServiceUpMethod="" Tag="" TargetButtonDownID=""
            TargetButtonUpID="" TargetControlID="TextBox1" Width="0">
        </cc1:NumericUpDownExtender>

    </div>
    <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    </form>
</body>
</html>

<html

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default3 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
}

error while compling Entity Framework Sample

asif.kalim — Thu, 06 Aug 2009 09:44:31 GMT

im trying to complie a sample application that i got from codeplex. Im getting following errors. Anyone please help me

thanks,

Error   3   Error 5: The required attribute 'Provider' is missing.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.edmx   109   7   GettingStarted_CS
Error   4   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   208   35   GettingStarted_CS
Error   5   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   231   34   GettingStarted_CS
Error   6   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   254   35   GettingStarted_CS
Error   7   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   300   37   GettingStarted_CS
Error   8   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   323   40   GettingStarted_CS
Error   9   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   346   37   GettingStarted_CS
Error   10   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   469   37   GettingStarted_CS
Error   11   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   636   37   GettingStarted_CS
Error   12   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   803   30   GettingStarted_CS
Error   13   The type arguments for method 'System.Data.Objects.DataClasses.StructuralObject.SetValidValue<T>(T, T, string)' cannot be inferred from the usage. Try specifying the type arguments explicitly.   D:\data\RnD\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.Designer.cs   826   32   GettingStarted_CS
Warning   1   The element 'Designer' in namespace 'http://schemas.microsoft.com/ado/2007/06/edmx' has invalid child element 'ReverseEngineer' in namespace 'http://schemas.microsoft.com/ado/2007/06/edmx'. List of possible elements expected: 'Diagrams' in namespace 'http://schemas.microsoft.com/ado/2007/06/edmx'.   D:\data\RnD\ERP Architecture\EntityFramework\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.edmx   14   6   GettingStarted_CS
Warning   2   The required attribute 'Provider' is missing.   D:\data\RnD\EFSamples\GettingStarted\GettingStarted_CS\MyTravelModel.edmx   109   8   GettingStarted_CS

Does silverlight support opengl or directx graphic engine.

egoZd — Thu, 13 Mar 2008 06:11:00 GMT

Does silverlight support opengl or directx graphic engine.

I m preparing to write a online game use silverlight. I have use it to make some demo found it work well as a client package hosting in brower. I hope it can support Opengl or other game graphic engine. Does it posible?

Thanks

Extension methods in .net 2.0

archana.ramaswamy — Wed, 02 Sep 2009 06:50:54 GMT

hi,

m trying to create an extension method in .net 2.0. Extension methods are supported in 3.5 but when i searched in google i got the below code.

namespace System.Runtime.CompilerServices

        [AttributeUsage(AttributeTargets.Method)]

       public sealed class ExtensionAttribute : Attribute

            public ExtensionAttribute() { }

In many sites its given that if we add the below code to 2.0 also the extension method will work. but still m getting error some thing like this

Cannot define a new extension method because the compiler required type 'System.Runtime.CompilerServices.ExtensionAttribute' cannot be found. Are you missing a reference to System.Core.dll?

please any one help me.

thanx

Add view to EDMX produces no results

rscott — Wed, 29 Oct 2008 15:04:29 GMT

I've got a small database with a single table and with a view. The view is coming from a different database (i.e, it does select * from db.dbo.someTable). I can select from the view fine using a query. When I try to add the view using "Update Model from Database", the wizard opens, I check my view under the views branch of the tree and click finish. The wizard goes away but the view is never added.

If I update again, I can still see the view under the "Add" portion of the wizard (not under refresh). No matter how many times I add it, it never actually adds and no errors pop up.

Also, as an interesting side note... if I close my EDMX window I cannot open it back up from the solution explorer. Double clicking on it simply expands the node. I have to restart studio to get it to work again.

Anyone seen this? The user who is adding the view is pretty restricted - the only thing it can do is select * from the view. Are there special permissions the user needs to use the model designer?

Metadata Path issue for Entity Connection "Unable to load the specified metadata resource."

rcfearn — Tue, 23 Dec 2008 02:31:08 GMT

I have two folders in a project Connections & Entities, I wan't to build an EntityConnection object in a class in the Connections folder that sets up connections for Entity Models in the Entities folder but I am having a problem with the MetaData property: When I run the code with the above setup and entityBuilder.Metadata = @"res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl"; I get an "Unable to load the specified metadata resource.", If I move the Entity Models out of the Entities folder into the root of the project it works correctly. If I move the Entity Models back to the Entities folder and change the MetaData string to @"res://*/Entities/Model1.csdl|res://*/Entities/Model1.ssdl|res://*/Entities/Model1.msl"; I get the following error : "The specified metadata path is not valid. A valid path must be either an existing directory, an existing file with extension '.csdl', '.ssdl', or '.msl', or a URI that identifies an embedded resource." Any ideas on how I can set this up correctly? Thanks in advance Rob

Acess silverlight source

xtinction84 — Fri, 14 Aug 2009 20:31:18 GMT

Hi there!

My question is very simple: I have this

    <div>
        <asp:Silverlight ID="XamlSilverlight" runat="server" Windowless="true"
            Source="~/ClientBin/SilverlightScatterPlot.xap" MinimumVersion="2.0.31005.0"
            Width="600" Height="600" />
    </div>

And i need to change the source of silverlight in server-side, so i need to acess the control of silverlight so:

 ContentPlaceHolder content = new ContentPlaceHolder();
            content = (ContentPlaceHolder)Page.Master.FindControl("MainContent");

(content.FindControl("XamlSilverlightDiagnostic") as DontKnow).Source = "~/ClientBin/SilverlightScatterPlot.xap"

How can i do to change the source of my silvellight control, in my Page.aspx

thanks

How to create empty xml from set of schema files

rsenthilnathan22 — Wed, 08 Jul 2009 08:11:35 GMT

Hi friends,

I have set of schema files, some schemas have reference schema also. I want to create empty xml file from that set of schema in 2.0 or later framework. how to do this. I have tried xsd.exe with serialization no proper xml and tried dataset also. Kindly let me know the solution

regards,

Senthilnathan Ragunathan

Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out.

sandeepbhutani304 — Sat, 08 Aug 2009 15:52:24 GMT

Hi, 

I am getting famous exception but in an uncommon scenario - 
Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out.

I hosted my website in a server and as soon as I fire a request I get this error alert. But to 
my surprise, when I access this same site from some other client machine (keeping previous 
same machine as server) it works flawlessly.  It simply means my server is OK 
and on same machine there is some problem in browser or somewhere else. 

I am already using enough AsyncPostBackTimeout. 
Can somebody please provide me a hint on what to do.

Thanks.

Download ASP.NET 3.5 Extensions Preview

Maikol — Tue, 28 Jul 2009 18:03:03 GMT

Where can I download the ASP.NET 3.5 Extensions Preview.

My controls in VS 2008 don't show me the Add Extensions tab, when I click them.

Can someone help me?

Access to the path c:\...\msc_cntr_0.txt is denied.

tinuverma — Fri, 13 Feb 2009 15:06:21 GMT

Hello Guys,
I deployed my web app to test environment and I keep getting this error at random:

Access to the path 'C:\Inetpub\mywebApp\msc_cntr_0.txt' is denied.

The state of the application when this error is generated:
the chart data source has only 1 record to draw with and its the first time it's being drawn (rendered).
If I go back to home page and then come to this, no errors. (read: no data changes...all i need to do is refresh the page).

Any ideas what might be wrong?

invalid association mapping

anthonyplanet — Tue, 29 Jul 2008 18:58:38 GMT

Hi , wondering if anyone has any ideas to this within my class mapping. I think the answer maybe in my db structure.
Anyway, all thoughts very much appreciated.

Invalid association mapping for member 'Asset.DesignImages'. 'DesignImage' is not an entity

I've notice VS studio is giving me warnings:

Warning    1    Value for property "Discriminator Property" cannot be empty.        0    0
Warning    2    Value for property "Inheritance Default" cannot be empty.        0    0

My DataBase
Asset
DesignText (foreignkey to asset.id )
DesignImage (foreignkey to asset.id )

Maybe i'm gettng nulls???

var query =

from d in db.Designs

from a in db.Assets

select new ProductViewHelper()

{

    theDesign = new Design(){DesignId = d.Id, Title = d.Title, DateField = DateTime.Now, PreviewImage = d.PreviewImage},

    theAsset = new Asset(){AssetId = a.Id, DesignId = a.DesignId, Date = a.Date},

    DesignTexts = (from x in a.DesignTexts select new DesignText()

    { DesignTextId = x.Id, Text = x.Text}).ToList(),

    DesignImages = (from y in a.DesignImages select new DesignImage()

    {Id = y.Id}).ToList()

};

        foreach (var p in query)
        {

                Response.Write(p.theAsset.id);


        }

Changing the Order of Fields in Entity Model for given Entity/Table

defyant_2004 — Thu, 23 Apr 2009 21:30:01 GMT

When the Entity Model is created from the SQL Server database, sometimes the order of the fields for a given table is listed differently than in the database. For example, in the database EmployeeID, EmployeeFirst, and EmployeeLast is the order for Employee table. In the EDM, it may list EmployeeFirst, EmployeeID, and EmployeeLast. Can this be changed in the EDM entity list to match the order of the database?

how to save data to relationship table with LINQ to SQL?

KentZhou — Fri, 26 Jun 2009 17:54:15 GMT

Suppose I have three tables: Tab1(Cola, ,,,,) Tab2(Colb,....), tab3(cola, colb,...)

Cola is primiary key for tab1, colb is primary key for tab2. Tab3 is a relationship of tab1 and tab2, so cola, colb is foreign keys for tab3.

For tab1 and tabl2, becuase thery are entity, so I can use datacontext db to add a new instance like:

db.Tab1s.InsertOnSubmit( tab1 obj);

db.Save();

db.Tab2s.InsertOnSubmit(tab2 obj);

db.Save();

But When I try to insert data to tab3 in simiar way:

db.Tab3s.InsertOnSubmit(tab3 obj);

I got exception eroro said that tabl3 has no primiary key. tab3 only have a index on cola, colb:

- ex {"Can't perform Create, Update or Delete operations on 'Table(Tab3)' because it has no primary key."} System.Exception {System.InvalidOperationException}

How to resolve this issue?

Asp.net extensons website template

yoel — Thu, 18 Jun 2009 11:11:39 GMT

Someone can help me how to see in visual studio web templates "Asp.net extensons website template " ?

Thanks

Yoel

Entity Framework add Function

Nezdet — Wed, 20 May 2009 17:08:21 GMT

Is it possible to add funtion to the entityframwork. Cause I drag an drop inside my Enities and nothing happens.

In Linq it does work.