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//Operator '+' cannot be applied to operands of type 'L' and 'L'

Posted By:      Posted Date: August 29, 2010    Points: 0   Category :WPF
  public L Mymethod<L>(L mydate, L myname) {   //it is getting following errro   //Operator '+' cannot be applied to operands of type 'L' and 'L'   return (myname+myname); }   Can any one give me help how to solve following error

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Operator '>=' cannot be applied to operands of type 'string' and 'string'


I want to compare two lebel text , but i am getting this error..

Compiler Error Message: CS0019: Operator '>=' cannot be applied to operands of type 'string' and 'string'

Source Error:

Line 39:         Label2.Text = DateTime.Now.AddDays(7).ToString("MM/dd/yyyy");
Line 40: Label3.Text = DateTime.Now.ToString("MM/dd/yyyy");
Line 41: if (Label2.Text>=Label2.Text)
Line 42: {

plz reply me ...how can i compare greater than and greater than equal to values of labels...


cannot be applied to operands of type 'string' and 'System.Guid'

MembershipUser myObject = Membership.GetUser(); string UserID = myObject.ProviderUserKey.ToString(); BurnbetDataContext db = new BurnbetDataContext(); var creditcard = from c in db.tbl_Payments where UserID == c.UserId select c; Column UserId = uniqueidentifier Compilation Error Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: CS0019: Operator '==' cannot be applied to operands of type 'string' and 'System.Guid'Source Error: Line 93: Line 94: var creditcard = from c in db.tbl_Payments Line 95: where UserID == c.UserId Line 96: select c; Line 97: Please help!

Operator '=' is not defined for type 'DBNull' and string "REJECTED".



I know that the problem is my field having NULL values. However, I don't know how to have it process the code even if the field have nulls

here's my code:

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        If e.Row.RowType = DataControlRowType.DataRow Then
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                Case "REJECTED"
                    e.Row.ForeColor = Drawing.Color.Red
                    e.Row.Font.Bold = True
                Case "ACCEPTED"
                    e.Row.ForeColor = Drawing.Color.Green
                Case Is = vbNullString
                    e.Row.ForeColor = Drawing.Color.Red
            End Select
            Select Case DataBinder.Eval(e.Row.DataItem, "Status")
                Case "Editing"
                    ' e.Row.Font.Bold = True
                    e.Row.Cells(6).ForeColor = Drawing.Color.DarkOrange
                Case "Active"
                    ' e.Row.Font.Bold = True
                    e.Row.Cells(6).ForeColor = Drawing.Color.DodgerBlue
            End Select
        End If
    End Sub

"IN" operator and error converting data type varchar to numeric



I hope someone can help me figure this out please...

I have this query that returns some student data - specifically the student's names, and some classes they're enroled in. What I'm trying to do is return multiple rows using the LIKE operator.

However when I run it and plug in the parameters I get the errror - "Error converting data type varchar to numeric". This error doesn't occur when there is only ONE studentId. Only when there are multiple studentIds. I know it's to do with the string of studentIds being passed, but I'm not sure how to fix it?

Should I be using varchar as the datatype to pass the studentIds? Or do I need to cast this as something else?

Any ideas, much appreciated.



	@StudentIds varchar(8000),
	@ProfileId numeric,
	@Fname varchar(50) OUTPUT,
	@Lname varchar(50) OUTPUT,
	@ClassName varchar (100) OUTPUT,
	@ClassName2 varchar (100) OUTPUT,
	@ClassName3 varchar (100) OUTPUT,
	@ClassName4 varchar (100) OUTPUT,
	@Class numeric OUTPUT,
	@Class2 numeric OUTPUT,
	@Class3 numeric OUTPUT,
	@Class4 numeric OUTPUT


@Fname = Fname, @Lname = Lname, @ClassName = C.ClassName, @ClassName2 = C2.ClassName, @ClassName3 = C3.ClassName, @ClassName4 = C4.ClassName,

Strange behavior when validation type of rule is applied in Infopath


I've designed InfoPath 2010 form which is browser enabled and 2007 compatible.

In one numeric text box, a Validation rule is written such that if user enters anything outside 0-100 range, it'll display an error message.


1. User opens the form and starts filling the controls.

2. User enters a number in this numeric text box and comes out of the textbox.

3. When focus is lost, validation rule gets triggered.

4. Infopath screen flickers (kind of), reposition itself to the original state.

Question 1: Why does it happen like this? This behavior does not happen in case of "Formatting" type of rule, but happens in "Validation" type of rule.

Question 2: Is validation rule a server-side? What about Formatting rule?

Question 3: This is not related to validation rule. When a textbox value is made right-aligned, we do not see the cursor inside textbox while entering the value. Is it the normal behavior? Is there any way to get rid of this?


TreeSelector : playing with generics and type inference

create a generic way to define a selection starting from a tree of objects, the most simpler way as possible.

Let's start with the beginning...
Here is a very simple little interface defining a node of the tree, basically, a value and the references to the child nodes.

UnTyped DataSets and Strongly Type DataSets

We all are use datasets as a means of carrier of data from one layer to another. Most of the time we are using weakly typed datasets. In this article I will explain the differences between weakly typed datasets and strongly type datasets

Gmail style multiple Sign-in type combo...is it possible in asp.net?


I am developing a multi-company application and want my users to give the functionality like the following to switch companies.


Is this possible? then how?

Please help


Type or namespace error.


A couple of days ago I started getting an unusual behavior when compiling Website projects. I have referenced class libraries added to my bin folder that are also correctely referenced in using statements in my aspx.cs code behind. When I compile, I get the 

Error 4 The type or namespace name 'CommonClassLibrary' could not be found (are you missing a using directive or an assembly reference?) C:\Dev\Fiscal_Portal\Implementation\FMS Portal Site_new\App_Code\BLL\DataTables.cs 1 7 C:\...\FMS Portal Site_new\

The type or namespace name 'CommonClassLibrary' could not be found (are you missing a using directive or an assembly reference?)

error message that would typically be received when the dll has not been added as a reference or added in a using statement.

I can eliminate the error by adding an


Bug: Does not change column type from nvarchar to ntext


Scenario: If you create a table with a column of type nvarchar, populate it with some content and try to modify it using the WebMatrix editor, from nvarchar to ntext, it does not display any error message or warning that this is not possible. It silently saves and reverts the change, back to nvarchar. Wasted some hours on this issue as I thought my column was ntext, but in fact was still nvarchar.

Expected behavior: It should change to ntext, or if SQL CE doesn't support that, it should notify the user that no change was applied.

The number of members in the conceptual type ... does not match with the number of members on the ob



I've added a scalar property to an entity and now ASP.NET Dynamic Data scaffolding throws this error:

The number of members in the conceptual type 'TrainingModel.Users' does not match with the number of members on the object side type 'TrainingModel.Users'. Make sure the number of members are the same.

This happens at the following line in global.asax:
model.RegisterContext(typeof(TrainingModel.TrainingEntities), new ContextConfiguration() { ScaffoldAllTables = true });

Please help!

System.Security.SecurityException: Request for the permission of type 'System.Web.AspNetHostingPerm


Good Day all,

Having an issue with an outside user accessing my IIS7 box. I do not have this problem when running the website from my host machine. I found this post: Http://forums.asp.net/t/1371394.aspx. I assure you that this is not a solution because I am not storing any of my files on a network share. 

What do you think my approach should be. 

I already have read rights to IIS user to my BIN folder. 

Thanks for the help. 

Need Syntax To Make Results of LINQ Union Return Non-Generic Type



I have the below SQL which works just fine:

SELECT     Message, CreateDate, AccountId, AlertTypeId
FROM       dbo.Alerts
SELECT     TOP (100) PERCENT Status, CreateDate, AccountId,
                          (SELECT     10 AS Expr1) AS AlertTypeId
FROM         dbo.StatusUpdates
WHERE AccountId = PassedInParameter

I have been going about trying to convert the above into a LINQ method and am having problems with return types.
As the above SQL illustrates, I am querying two distinct LINQ tables - Alerts and StatusUpdates -
and then attempting to perform a Union on them. In order to do the union in LINQ, I have to have agreeing types. So, I
am using "var" to make the results of "alerts" and "updates" generic before the union.  

public IList GetStatusUpdatesAsAlertsByAccountId<T>(Int32 accountId)
            using (WorkbookDataContext dc = _conn.GetCont

The type 'System.Data.Linq.DataContext' is defined in an assembly that is not referenced. You must



This is frustrating, and I don't know how to solve it.

I have a strange problem. I am adding a LinqDatasource object, and set the context:

        protected void LinqDataSource_ContextCreating(object sender, LinqDataSourceContextEventArgs e)
            e.ObjectInstance = new KaruselaDataContext(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);

Then I get this error:
The type 'System.Data.Linq.DataContext' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Data.Linq, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089'.


On web.config I already have this:
<add assembly="System.Data.Linq, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>

NOTE: The datacontext is in a different project (DLL proect) where I added a refernce to System.Data.Linq.

is there another way adding a refernce to a web project? or only though teh web.config?


type object parameter



I have a problem I can't figure out.

I've been trying to add a listbox with multi select enabled as a parameter to my select statement in sqldatasource.

So i created a function like this :

string strItemTypes = "";
foreach (ListItem li in lbItemType.Items)
   if (li.Selected)
      strItemTypes += "," + li.Value;
strItemTypes = strItemTypes.Substring(1);

which gives me the selected items like this for example : "1,2,3"...
Then I've been trying to add it to my sql select statement :

SELECT tblOfficesItems.idOfficesItems, tblStockItems.Name, tblStockItems.Description, tblStockItemTypes.TypeItem, tblStockItems.Notes FROM tblOfficesItems INNER JOIN tblStockItems ON tblOfficesItems.fkItem = tblStockItems.idItem INNER JOIN tblStockItemTypes ON tblStockItems.fkTypeItem = tblStockItemTypes.idTypeItem WHERE tblStockItems.fkTypeItem IN ( @fkTypeItems )

using a hiddenfield with a controlparameter of type=object
but it just don't seem to work, seems like the data just won't bind or something and I don't get any errors so I'm confused!!

then i tried this :

SELECT tblOfficesItems.idOfficesItems, tblStockItems.Name

Activation error occured while trying to get instance of type Database, key "DBName"


Im using Enterprise library 5.0
I have a scenario, where I have to access two different databases in my application.

Basically this application is a webservice,delployed on my local for testing purpose.
I'm trying to access this web method from diffent windows application, default connection works fine but the other database throw's exception.

Problem is only my defaultDatabase is works fine, if I change defaultDatabase="MYCON1" with "MYCON2" it works fine, if I try to access the other database which is not default, throws exception.

<dataConfiguration defaultDatabase="MYCON1" />
<add name="MYCON1" connectionString="Data Source=server1;Initial Catalog=dbName1;User Id=Username1;Password=password1;"

" />
<add name="MYCON2" connectionString="Data Source=Server2;Initial Catalog=dbName2;User Id=Username2;Password=password2;"
providerName="System.Data.SqlClient" />

Database myDB=EnterpriseLibraryContainer.Current.GetInstance<Database>(); --> works fine for the default database (MYCON1)

Database myDB=EnterpriseLibraryCo

"Type ASP.x is not defined" error for dynamic user control when publishing updateable


I have a user control (ContainerCtrl) which programmatically instantiates another user control (SimpleCtrl) in OnLoad. It builds and runs fine, but when I publish it I get the error "error BC30002: Type 'ASP.SimpleCtrl' is not defined." (If I publish without the "updateable" option there's no error, but I need the site to be updateable.)

I assume this has to do with the particulars of how the assembly(ies) are built for the different compiler options. My question is, how can I get it to work properly for "updateable" publishing?

VS 2008 / .NET 3.5 sp1

The code follows (web.config is the default from Visual Studio).

Many thanks, Dave


<%@ Control Language="VB" ClassName="SimpleCtrl" CodeFile="SimpleCtrl.ascx.vb" Inherits="_SimpleCtrl" %>

    Simple control


Partial Class _SimpleCtrl
    Inherits UserControl

    'Nothing to see here.

End Class


<%@ Control Language="VB" CodeFile="ContainerCtrl.ascx.vb" Inherits="_ContainerCtrl"

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