Populate a dropdown list with a variable from a Querystring

Jim via DotNetMonster.com

Hi,

I'm passing a variable to another page through a querystring. I then want
to use that variable to retrieve records from a database to poulate a
dropdownlist. I can read the variable from the querystring but I'm not sure
how to pass that value. I get the error that IntCourseID is not declared in:

<asp:DropDownLi st id="fLessonID" runat="server" DataValueField= "LessonID"
DataSource="<%# GetLessons(IntC ourseID) %>"

I tried moving the querystring outside the page load but that didn't work:

This is the code I have:

<%@ Page Language="VB" Debug="true" validaterequest ="false" %>

<script runat="server">

Sub Page_Load(sende r As Object, e As EventArgs)
If Page.IsPostBack = False Then
Dim IntCourseID as Integer
IntCourseID = Request.QuerySt ring( "CourseID" )

End If
End Sub
Function GetLessons(ByVa l courseID As Integer) As
System.Data.IDa taReader
Dim connectionStrin g As String = "server='(local )';
trusted_connect ion=true; database='xx'"
Dim dbConnection As System.Data.IDb Connection = New
System.Data.Sql Client.SqlConne ction(connectio nString)

Dim queryString As String = "SELECT [tblLesson].[LessonID],
[tblLesson].[LessonTitle] FROM [tblLesson] WHERE ("& _
"[tblLesson].[CourseID] = @CourseID)"
Dim dbCommand As System.Data.IDb Command = New
System.Data.Sql Client.SqlComma nd
dbCommand.Comma ndText = queryString
dbCommand.Conne ction = dbConnection

Dim dbParam_courseI D As System.Data.IDa taParameter = New
System.Data.Sql Client.SqlParam eter
dbParam_courseI D.ParameterName = "@CourseID"
dbParam_courseI D.Value = courseID
dbParam_courseI D.DbType = System.Data.DbT ype.Int32
dbCommand.Param eters.Add(dbPar am_courseID)

dbConnection.Op en
Dim dataReader As System.Data.IDa taReader =
dbCommand.Execu teReader(System .Data.CommandBe havior.CloseCon nection)

Return dataReader
End Function

Sub addButton_Click (sender As Object, e As EventArgs)
Response.Redire ct("selectPage. aspx")
End Sub

</script>
<html>
<head>
</head>
<body leftmargin="0" topmargin="0">
<form runat="server">
<asp:DropDownLi st id="fLessonID" runat="server"
DataValueField= "LessonID" DataSource="<%# GetLessons(IntC ourseID) %>"
DataTextField=" LessonTitle"></asp:DropDownLis t>
<asp:Button id="addButton" onclick="addBut ton_Click" runat="server"
Text="Next"></asp:Button>

</form>
</body>
</html>

Thanks for any help

--
Message posted via http://www.dotnetmonster.com

Nov 19 '05 #1

Subscribe Reply

4014

DotNetJerome

Hi Jim,

I understood your probleim in the following way after reading your code...

You have a Integer Variable (IntCourseID) in your code behind fi.e...and you
want to use that value in your .aspx page. Am I right...?

If I'm right....then solution for your problem is...

Have a hidden control...and assign your querystring value (CourseId) to the
value of the hidden control. Now you can use that control in your .aspx page
code, to bind with the ddl.

Cheers,

Jerome. M

"Jim via DotNetMonster.c om" wrote:

Hi,

I'm passing a variable to another page through a querystring. I then want
to use that variable to retrieve records from a database to poulate a
dropdownlist. I can read the variable from the querystring but I'm not sure
how to pass that value. I get the error that IntCourseID is not declared in:

<asp:DropDownLi st id="fLessonID" runat="server" DataValueField= "LessonID"
DataSource="<%# GetLessons(IntC ourseID) %>"

I tried moving the querystring outside the page load but that didn't work:

This is the code I have:

<%@ Page Language="VB" Debug="true" validaterequest ="false" %>

<script runat="server">

Sub Page_Load(sende r As Object, e As EventArgs)
If Page.IsPostBack = False Then
Dim IntCourseID as Integer
IntCourseID = Request.QuerySt ring( "CourseID" )

End If
End Sub
Function GetLessons(ByVa l courseID As Integer) As
System.Data.IDa taReader
Dim connectionStrin g As String = "server='(local )';
trusted_connect ion=true; database='xx'"
Dim dbConnection As System.Data.IDb Connection = New
System.Data.Sql Client.SqlConne ction(connectio nString)

Dim queryString As String = "SELECT [tblLesson].[LessonID],
[tblLesson].[LessonTitle] FROM [tblLesson] WHERE ("& _
"[tblLesson].[CourseID] = @CourseID)"
Dim dbCommand As System.Data.IDb Command = New
System.Data.Sql Client.SqlComma nd
dbCommand.Comma ndText = queryString
dbCommand.Conne ction = dbConnection

Dim dbParam_courseI D As System.Data.IDa taParameter = New
System.Data.Sql Client.SqlParam eter
dbParam_courseI D.ParameterName = "@CourseID"
dbParam_courseI D.Value = courseID
dbParam_courseI D.DbType = System.Data.DbT ype.Int32
dbCommand.Param eters.Add(dbPar am_courseID)

dbConnection.Op en
Dim dataReader As System.Data.IDa taReader =
dbCommand.Execu teReader(System .Data.CommandBe havior.CloseCon nection)

Return dataReader
End Function

Sub addButton_Click (sender As Object, e As EventArgs)
Response.Redire ct("selectPage. aspx")
End Sub

</script>
<html>
<head>
</head>
<body leftmargin="0" topmargin="0">
<form runat="server">
<asp:DropDownLi st id="fLessonID" runat="server"
DataValueField= "LessonID" DataSource="<%# GetLessons(IntC ourseID) %>"
DataTextField=" LessonTitle"></asp:DropDownLis t>
<asp:Button id="addButton" onclick="addBut ton_Click" runat="server"
Text="Next"></asp:Button>

</form>
</body>
</html>

Thanks for any help

--
Message posted via http://www.dotnetmonster.com

Nov 19 '05 #2

Malik Asif Joyia

Hello
Dear Jim!
First the problem with your code is that you are declaring a Variable in
pageload event "IntCourseI D" that will be destroyed when this event will
reach its end.
First Declare this variable in the GetLessons function
IntCourseID = Request.QuerySt ring( "CourseID" )
so that this variable with its value can be accessed.

Regards
Malik Asif
ASP.NET,VB.NET
"Jim via DotNetMonster.c om" <fo***@DotNetMo nster.com> wrote in message
news:85******** *************** *******@DotNetM onster.com...

Hi,

I'm passing a variable to another page through a querystring. I then want
to use that variable to retrieve records from a database to poulate a
dropdownlist. I can read the variable from the querystring but I'm not sure how to pass that value. I get the error that IntCourseID is not declared in:
<asp:DropDownLi st id="fLessonID" runat="server" DataValueField= "LessonID"
DataSource="<%# GetLessons(IntC ourseID) %>"

I tried moving the querystring outside the page load but that didn't work:

This is the code I have:

<%@ Page Language="VB" Debug="true" validaterequest ="false" %>

<script runat="server">

Sub Page_Load(sende r As Object, e As EventArgs)
If Page.IsPostBack = False Then
Dim IntCourseID as Integer
IntCourseID = Request.QuerySt ring( "CourseID" )

End If
End Sub
Function GetLessons(ByVa l courseID As Integer) As
System.Data.IDa taReader
Dim connectionStrin g As String = "server='(local )';
trusted_connect ion=true; database='xx'"
Dim dbConnection As System.Data.IDb Connection = New
System.Data.Sql Client.SqlConne ction(connectio nString)

Dim queryString As String = "SELECT [tblLesson].[LessonID],
[tblLesson].[LessonTitle] FROM [tblLesson] WHERE ("& _
"[tblLesson].[CourseID] = @CourseID)"
Dim dbCommand As System.Data.IDb Command = New
System.Data.Sql Client.SqlComma nd
dbCommand.Comma ndText = queryString
dbCommand.Conne ction = dbConnection

Dim dbParam_courseI D As System.Data.IDa taParameter = New
System.Data.Sql Client.SqlParam eter
dbParam_courseI D.ParameterName = "@CourseID"
dbParam_courseI D.Value = courseID
dbParam_courseI D.DbType = System.Data.DbT ype.Int32
dbCommand.Param eters.Add(dbPar am_courseID)

dbConnection.Op en
Dim dataReader As System.Data.IDa taReader =
dbCommand.Execu teReader(System .Data.CommandBe havior.CloseCon nection)

Return dataReader
End Function

Sub addButton_Click (sender As Object, e As EventArgs)
Response.Redire ct("selectPage. aspx")
End Sub

</script>
<html>
<head>
</head>
<body leftmargin="0" topmargin="0">
<form runat="server">
<asp:DropDownLi st id="fLessonID" runat="server"
DataValueField= "LessonID" DataSource="<%# GetLessons(IntC ourseID) %>"
DataTextField=" LessonTitle"></asp:DropDownLis t>
<asp:Button id="addButton" onclick="addBut ton_Click" runat="server" Text="Next"></asp:Button>

</form>
</body>
</html>

Thanks for any help

--
Message posted via http://www.dotnetmonster.com

Nov 19 '05 #3

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