problem with selectedvalue of dropdownlist

[Chris]

Hi,

When choosing a value in the dropdownlist, i try to put that selectedvalue
in the label, but i always get the first value 'a'.
EnableViewState is by default set to true, so ... what's wrong in my code?
Thanks
Chris

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load
Dim ddl As New DropDownList
Dim z As ListItem
Dim kz As String
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)

If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
z = New ListItem("c", "c")
ddl.Items.Add(z )
End If
End Sub
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" ></asp:Label>
</form>

[Lloyd Sheen]

"Chris" <ss*@qsd.dcwrot e in message
news:uT******** ******@TK2MSFTN GP05.phx.gbl...

Hi,

When choosing a value in the dropdownlist, i try to put that selectedvalue
in the label, but i always get the first value 'a'.
EnableViewState is by default set to true, so ... what's wrong in my code?
Thanks
Chris

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load
Dim ddl As New DropDownList
Dim z As ListItem
Dim kz As String
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)

If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
z = New ListItem("c", "c")
ddl.Items.Add(z )
End If
End Sub
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" ></asp:Label>
</form>

You are recreating the dropdownlist every time you select an item. Since
you have AutoPostBack on you should be using a SelectionChange d routine to
pull the information from. Why are you creating the dropdown in code?

LS

[Rain]

Put your label setting code in the pre-render event or the index select
changed event for the dropdown box.


"Chris" <ss*@qsd.dcwrot e in message
news:uT******** ******@TK2MSFTN GP05.phx.gbl...

Hi,

When choosing a value in the dropdownlist, i try to put that selectedvalue
in the label, but i always get the first value 'a'.
EnableViewState is by default set to true, so ... what's wrong in my code?
Thanks
Chris

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load
Dim ddl As New DropDownList
Dim z As ListItem
Dim kz As String
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)

If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
z = New ListItem("c", "c")
ddl.Items.Add(z )
End If
End Sub
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" ></asp:Label>
</form>

[Chris]

Thanks for replying.
I don't know in advance how many dropdownlists i need. This is coming from a
database, so i have to create them by code.
Doing like this, there is no SelectionChange d procedure available ...
"Lloyd Sheen" <[e-mail] in bericht
news:uV******** *****@TK2MSFTNG P02.phx.gbl...

>
"Chris" <ss*@qsd.dcwrot e in message
news:uT******** ******@TK2MSFTN GP05.phx.gbl...

>Hi,

When choosing a value in the dropdownlist, i try to put that
selectedvalu e in the label, but i always get the first value 'a'.
EnableViewStat e is by default set to true, so ... what's wrong in my
code?
Thanks
Chris

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventAr gs) Handles Me.Load
Dim ddl As New DropDownList
Dim z As ListItem
Dim kz As String
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)

If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
z = New ListItem("c", "c")
ddl.Items.Add(z )
End If
End Sub
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" ></asp:Label>
</form>

You are recreating the dropdownlist every time you select an item. Since
you have AutoPostBack on you should be using a SelectionChange d routine to
pull the information from. Why are you creating the dropdown in code?

LS

[Rain]

Yes there is

You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is the
C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDownLi st1.SelectedInd exChanged += new
System.EventHan dler(myFunction Name);

public void myFunctionName( object sender, System.EventArg s e )


"Chris" <ss*@qsd.dcwrot e in message
news:uM******** ******@TK2MSFTN GP02.phx.gbl...

Thanks for replying.
I don't know in advance how many dropdownlists i need. This is coming from
a database, so i have to create them by code.
Doing like this, there is no SelectionChange d procedure available ...
"Lloyd Sheen" <[e-mail] in bericht
news:uV******** *****@TK2MSFTNG P02.phx.gbl...

>>
"Chris" <ss*@qsd.dcwrot e in message
news:uT******* *******@TK2MSFT NGP05.phx.gbl.. .

>>Hi,

When choosing a value in the dropdownlist, i try to put that
selectedval ue in the label, but i always get the first value 'a'.
EnableViewSta te is by default set to true, so ... what's wrong in my
code?
Thanks
Chris

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventA rgs) Handles Me.Load
Dim ddl As New DropDownList
Dim z As ListItem
Dim kz As String
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)

If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
z = New ListItem("c", "c")
ddl.Items.Add(z )
End If
End Sub
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" ></asp:Label>
</form>

You are recreating the dropdownlist every time you select an item. Since
you have AutoPostBack on you should be using a SelectionChange d routine
to pull the information from. Why are you creating the dropdown in code?

LS

[Mark Rae [MVP]]

"Rain" <[e-mail] wrote in message
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..

You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is the
C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDownLi st1.SelectedInd exChanged += new
System.EventHan dler(myFunction Name);

Remember that dynamic controls which need to have events wired up need to be
created in Page_Init or Page_PreInit - Page_Load is usually too late in the
page cycle...
--
Mark Rae
ASP.NET MVP
http://www.markrae.net

[Chris]

I resolved my problem like this:
Partial Class test
Inherits System.Web.UI.P age
Friend ddl As New DropDownList
Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load

Dim z As ListItem
Dim kz As String
If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
End If
End Sub

Protected Sub Page_PreInit(By Val sender As Object, ByVal e As
System.EventArg s) Handles Me.PreInit
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)
End Sub
End Class
Protected Sub Page_PreInit(By Val sender As Object, ByVal e As
System.EventArg s) Handles Me.PreInit
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)
End Sub

But this generates a new problem to me: how can i program that in code?
Assume i need 5 dropdownlists: i can create dim ddl() and then redim
ddl(number needed). But how to do that with Friend, which must be outside
all sub? Or is there a better way to do this?


"Mark Rae [MVP]" <ma**@markNOSPA Mrae.netschreef in bericht
news:%2******** ********@TK2MSF TNGP03.phx.gbl. ..

"Rain" <[e-mail] wrote in message
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..

>You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is
the C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDownL ist1.SelectedIn dexChanged += new
System.EventHa ndler(myFunctio nName);

Remember that dynamic controls which need to have events wired up need to
be created in Page_Init or Page_PreInit - Page_Load is usually too late in
the page cycle...
--
Mark Rae
ASP.NET MVP
http://www.markrae.net

[Chris]

or maybe better, but still same problem: how to code all the Friend
variables i need ..

Partial Class test
Inherits System.Web.UI.P age
Friend ddl As New DropDownList

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load
Dim z As ListItem
If Not Page.IsPostBack Then
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
End If
End Sub

Protected Sub Page_PreInit(By Val sender As Object, ByVal e As
System.EventArg s) Handles Me.PreInit
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)
AddHandler ddl.SelectedInd exChanged, AddressOf selectddl
End Sub
Protected Sub selectddl(ByVal sender As Object, ByVal e As
System.EventArg s)
Dim kz As String
kz = ddl.SelectedVal ue
Label1.Text = kz
End Sub
End Class

"Chris" <ss*@qsd.dcschr eef in bericht
news:us******** ******@TK2MSFTN GP03.phx.gbl...

>I resolved my problem like this:
Partial Class test
Inherits System.Web.UI.P age
Friend ddl As New DropDownList
Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Load

Dim z As ListItem
Dim kz As String
If Page.IsPostBack Then
kz = ddl.SelectedVal ue
Label1.Text = kz
Else
z = New ListItem("a", "a")
ddl.Items.Add(z )
z = New ListItem("b", "b")
ddl.Items.Add(z )
End If
End Sub

Protected Sub Page_PreInit(By Val sender As Object, ByVal e As
System.EventArg s) Handles Me.PreInit
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)
End Sub
End Class
Protected Sub Page_PreInit(By Val sender As Object, ByVal e As
System.EventArg s) Handles Me.PreInit
ddl.AutoPostBac k = True
form1.Controls. Add(ddl)
End Sub

But this generates a new problem to me: how can i program that in code?
Assume i need 5 dropdownlists: i can create dim ddl() and then redim
ddl(number needed). But how to do that with Friend, which must be outside
all sub? Or is there a better way to do this?


"Mark Rae [MVP]" <ma**@markNOSPA Mrae.netschreef in bericht
news:%2******** ********@TK2MSF TNGP03.phx.gbl. ..

>"Rain" <[e-mail] wrote in message
news:%2******* *********@TK2MS FTNGP04.phx.gbl ...

>>You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is
the C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDown List1.SelectedI ndexChanged += new
System.EventH andler(myFuncti onName);

Remember that dynamic controls which need to have events wired up need to
be created in Page_Init or Page_PreInit - Page_Load is usually too late
in the page cycle...
--
Mark Rae
ASP.NET MVP
http://www.markrae.net

[Rain]

Where did I mention doing it in the Page_Load ?
"Mark Rae [MVP]" <ma**@markNOSPA Mrae.netwrote in message
news:%2******** ********@TK2MSF TNGP03.phx.gbl. ..

"Rain" <[e-mail] wrote in message
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..

>You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is
the C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDownL ist1.SelectedIn dexChanged += new
System.EventHa ndler(myFunctio nName);

Remember that dynamic controls which need to have events wired up need to
be created in Page_Init or Page_PreInit - Page_Load is usually too late in
the page cycle...
--
Mark Rae
ASP.NET MVP
http://www.markrae.net

[Chris]

I don't know ...
If you really want to help, please just tell me what's wrong
Thanks
"Rain" <[e-mail] schreef in bericht
news:%2******** ********@TK2MSF TNGP04.phx.gbl. ..

Where did I mention doing it in the Page_Load ?
"Mark Rae [MVP]" <ma**@markNOSPA Mrae.netwrote in message
news:%2******** ********@TK2MSF TNGP03.phx.gbl. ..

>"Rain" <[e-mail] wrote in message
news:%2******* *********@TK2MS FTNGP04.phx.gbl ...

>>You can create an event handler to service the event. Have a look in the
help for adding event handlers. Its a fairly simple one to do. This is
the C# equiv, ( For VB lookup the Addhandler in help ).

this.DropDown List1.SelectedI ndexChanged += new
System.EventH andler(myFuncti onName);

Remember that dynamic controls which need to have events wired up need to
be created in Page_Init or Page_PreInit - Page_Load is usually too late
in the page cycle...
--
Mark Rae
ASP.NET MVP
http://www.markrae.net