Listbox & Object Not Referenced

yop

All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object
reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text = stUsers.Selecte dItem.Text
Line 86:
Line 87: 'Get the user details and fill textboxes

Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI.W ebControls.List Control.OnSelec tedIndexChang
ed(EventArgs e)

System.Web.UI.W ebControls.List Box.System.Web. UI.IPostBackD
ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

Nov 17 '05 #1

Subscribe Reply

2252

Kevin Spencer

Unless an Item has been selected, this value will be null.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:0a******** *************** *****@phx.gbl.. .

All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object
reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text = stUsers.Selecte dItem.Text
Line 86:
Line 87: 'Get the user details and fill textboxes

Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI.W ebControls.List Control.OnSelec tedIndexChang
ed(EventArgs e)

System.Web.UI.W ebControls.List Box.System.Web. UI.IPostBackD
ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

Nov 17 '05 #2

yop

Kevin

I have an item selected alright, daft idea but could it
be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender As
Object, ByVal e As System.EventArg s) _
Handles lstUsers.Select edIndexChanged

'Need to bind the textboxes from the choice picked out
from the list
UserName.Text = lstUsers.Select edItem.Text
thanks

-----Original Message-----
Unless an Item has been selected, this value will be null.
--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:0a******* *************** ******@phx.gbl. ..
All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text = stUsers.Selecte dItem.Text Line 86:
Line 87: 'Get the user details and fill textboxes
Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI.W ebControls.List Control.OnSelec tedIndexChang ed(EventArgs e)

System.Web.UI.W ebControls.List Box.System.Web. UI.IPostBackD ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

.

Nov 17 '05 #3

Tapasvi

Try using .SelectedValue property.....

TextBox1.Text = ListBox1.Select edValue()

If it fails too, i would check whether it is selected the
first time user comes on the web page. If that is also
set, and it is not working, i will try to see
whether "value" property returns anything. If that fails,
i have no idea why its not working.....

Since it is going to "SelectedIndexC hanged" event i am
hoping that the "AutoPostBa ck" is set to true for your
control.

Thanks,

Tapasvi

-----Original Message-----
Kevin

I have an item selected alright, daft idea but could it
be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender As
Object, ByVal e As System.EventArg s) _
Handles lstUsers.Select edIndexChanged

'Need to bind the textboxes from the choice picked out
from the list
UserName.Tex t = lstUsers.Select edItem.Text
thanks
-----Original Message-----
Unless an Item has been selected, this value will be

null.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:0a****** *************** *******@phx.gbl ...
All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException:Object reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text =stUsers.Select edItem.Text Line 86:
Line 87: 'Get the user details and filltextboxes
Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI. WebControls.Lis tControl.OnSele ctedIndexChang ed(EventArgs e)

System.Web.UI. WebControls.Lis tBox.System.Web .UI.IPostBackD ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

.

.

Nov 17 '05 #4

Kevin Spencer

Is the ListBox's AutoPostBack property set to True?

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:04******** *************** *****@phx.gbl.. .

Kevin

I have an item selected alright, daft idea but could it
be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender As
Object, ByVal e As System.EventArg s) _
Handles lstUsers.Select edIndexChanged

'Need to bind the textboxes from the choice picked out
from the list
UserName.Text = lstUsers.Select edItem.Text
thanks
-----Original Message-----
Unless an Item has been selected, this value will be

null.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:0a******* *************** ******@phx.gbl. ..
All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text = stUsers.Selecte dItem.Text Line 86:
Line 87: 'Get the user details and fill textboxes
Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI.W ebControls.List Control.OnSelec tedIndexChang ed(EventArgs e)

System.Web.UI.W ebControls.List Box.System.Web. UI.IPostBackD ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

.

Nov 17 '05 #5

Kevin Spencer

Another possiblity: Is the ListBox dynamically added to the Page?

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:04******** *************** *****@phx.gbl.. .

Kevin

I have an item selected alright, daft idea but could it
be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender As
Object, ByVal e As System.EventArg s) _
Handles lstUsers.Select edIndexChanged

'Need to bind the textboxes from the choice picked out
from the list
UserName.Text = lstUsers.Select edItem.Text
thanks
-----Original Message-----
Unless an Item has been selected, this value will be

null.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:0a******* *************** ******@phx.gbl. ..
All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Select edItem
Line 85: UserName.Text = stUsers.Selecte dItem.Text Line 86:
Line 87: 'Get the user details and fill textboxes
Source File: C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
Register\AssetR egister\ViewUse rs.aspx.vb:85

System.Web.UI.W ebControls.List Control.OnSelec tedIndexChang ed(EventArgs e)

System.Web.UI.W ebControls.List Box.System.Web. UI.IPostBackD ataHandler.Rais ePostDataChange dEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

.

Nov 17 '05 #6

Tapasvi

Yes it is a property. Here is the code that works fine on
my machine.....

Code behind >>>>>

Private Sub ListBox1_Select edIndexChanged( ByVal sender As
System.Object, ByVal e As System.EventArg s)
Handles ListBox1.Select edIndexChanged
TextBox1.Text = ListBox1.Select edValue()
End Sub

ASPX code >>>>>

<HTML>
<HEAD>
<title>WebForm1 </title>
<meta name="GENERATOR " content="Micros oft
Visual Studio .NET 7.1">
<meta name="CODE_LANG UAGE" content="Visual
Basic .NET 7.1">
<meta name="vs_defaul tClientScript"
content="JavaSc ript">
<meta name="vs_target Schema"
content="http://schemas.microso ft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post"
runat="server">
<asp:ListBox id="ListBox1"
style="Z-INDEX: 101; LEFT: 288px; POSITION: absolute; TOP:
168px"
runat="server"
Width="160px" Height="168px" AutoPostBack="T rue">
<asp:ListItem
Value="Tapasvi" >Tapasvi</asp:ListItem>
<asp:ListItem Value="Tap
at Work">Tap at Work</asp:ListItem>
</asp:ListBox>
<asp:TextBox id="TextBox1"
style="Z-INDEX: 102; LEFT: 288px; POSITION: absolute; TOP:
120px"

runat="server"> </asp:TextBox>
</form>
</body>
</HTML>

Thanks,

Tap

-----Original Message-----
Aye it is set alright.

The SelectedValue is not a property of the listbox?
-----Original Message-----
Is the ListBox's AutoPostBack property set to True?

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:04****** *************** *******@phx.gbl ...
Kevin

I have an item selected alright, daft idea but could it
be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal senderAs Object, ByVal e As System.EventArg s) _
HandleslstUsers.Selec tedIndexChanged
'Need to bind the textboxes from the choice picked out
from the list
UserName.Text = lstUsers.Select edItem.Text
thanks

>-----Original Message-----
>Unless an Item has been selected, this value will be
null.
>
>--
>HTH,
>
>Kevin Spencer
>Microsoft MVP
>..Net Developer
>http://www.takempis.com
>The more I learn, the less I know.
>
>"yop" <yo*@oceanfree. net> wrote in message
>news:0a******* *************** ******@phx.gbl. ..
>> All
>>
>> When I try to get the text from my listbox I am getan >> error which is listed below.
>>
>> Any ideas?
>>
>> Thanks
>>
>> Object reference not set to an instance of anobject. >> Description: An unhandled exception occurred duringthe >> execution of the current web request. Please reviewthe >> stack trace for more information about the error and
>> where it originated in the code.
>>
>> Exception Details: System.NullRefe renceException:
Object
>> reference not set to an instance of an object.
>>
>> Source Error:
>>
>>
>> Line 83: 'Need to bind the textboxes fromthe >> choice picked out from the list
>> Line 84: ' Dim ListItem As ListItem =
>> lstUsers.Select edItem
>> Line 85: UserName.Text =
stUsers.Selecte dItem.Text
>> Line 86:
>> Line 87: 'Get the user details and fill
textboxes
>>
>> Source File: C:\Dev\Asset Register
>> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb Line: 85
>>
>> Stack Trace:
>>
>>
>> [NullReferenceEx ception: Object reference not setto an >> instance of an object.]
>>AssetRegister. ViewUser.lstUse rs_SelectedInde xChanged >> (Object sender, EventArgs e) in C:\Dev\AssetRegister >> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb:85
>>
>>
System.Web.UI. WebControls.Lis tControl.OnSele ctedIndexChang >> ed(EventArgs e)
>>
>>
System.Web.UI. WebControls.Lis tBox.System.Web .UI.IPostBackD >> ataHandler.Rais ePostDataChange dEvent()
>> System.Web.UI.P age.RaiseChange dEvents()
>> System.Web.UI.P age.ProcessRequ estMain()
>>
>>
>>
>>
>>
>
>
>.
>

.

.

Nov 17 '05 #7

yop

No the listbox is added at design time but the items are
added from the DB at run time. Maybe that is an issue.
Extremely frustating!! :(

Also the selectedvalue property is telling it is "not a
member of System.Web.UI.W ebControls.List box.

I am using Framework 1.1, there is an issue with using
the webcontrols and this version I think??

Would I be better of using a 3rd party list or data list
or something?

-----Original Message-----
Yes it is a property. Here is the code that works fine onmy machine.....

Code behind >>>>>

Private Sub ListBox1_Select edIndexChanged( ByVal sender As System.Object, ByVal e As System.EventArg s)
Handles ListBox1.Select edIndexChanged
TextBox1.Text = ListBox1.Select edValue()
End Sub

ASPX code >>>>>

<HTML>
<HEAD>
<title>WebForm1 </title>
<meta name="GENERATOR " content="Micros oft
Visual Studio .NET 7.1">
<meta name="CODE_LANG UAGE" content="VisualBasic .NET 7.1">
<meta name="vs_defaul tClientScript"
content="JavaS cript">
<meta name="vs_target Schema"
content="htt p://schemas.microso ft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post"
runat="server" >
<asp:ListBox id="ListBox1"
style="Z-INDEX: 101; LEFT: 288px; POSITION: absolute; TOP:168px"
runat="server"
Width="160px " Height="168px" AutoPostBack="T rue">
<asp:ListItem
Value="Tapasvi ">Tapasvi</asp:ListItem>
<asp:ListItem Value="Tap
at Work">Tap at Work</asp:ListItem>
</asp:ListBox>
<asp:TextBox id="TextBox1"
style="Z-INDEX: 102; LEFT: 288px; POSITION: absolute; TOP:120px"

runat="server"> </asp:TextBox>
</form>
</body>
</HTML>

Thanks,

Tap

-----Original Message-----
Aye it is set alright.

The SelectedValue is not a property of the listbox?
-----Original Message-----
Is the ListBox's AutoPostBack property set to True?

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:04***** *************** ********@phx.gb l...
Kevin

I have an item selected alright, daft idea but could it be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender
As
Object, ByVal e As System.EventArg s) _
Handles

lstUsers.Sele ctedIndexChange d

'Need to bind the textboxes from the choice picked
out from the list
UserName.Text = lstUsers.Select edItem.Text
thanks

>-----Original Message-----
>Unless an Item has been selected, this value will be
null.
>
>--
>HTH,
>
>Kevin Spencer
>Microsoft MVP
>..Net Developer
>http://www.takempis.com
>The more I learn, the less I know.
>
>"yop" <yo*@oceanfree. net> wrote in message
>news:0a******* *************** ******@phx.gbl. ..
>> All
>>
>> When I try to get the text from my listbox I am get
an
>> error which is listed below.
>>
>> Any ideas?
>>
>> Thanks
>>
>> Object reference not set to an instance of an

object.
>> Description: An unhandled exception occurred
duringthe
>> execution of the current web request. Please
reviewthe
>> stack trace for more information about the error

and >> where it originated in the code.
>>
>> Exception Details: System.NullRefe renceException:
Object
>> reference not set to an instance of an object.
>>
>> Source Error:
>>
>>
>> Line 83: 'Need to bind the textboxes from

the
>> choice picked out from the list
>> Line 84: ' Dim ListItem As ListItem =
>> lstUsers.Select edItem
>> Line 85: UserName.Text =
stUsers.Selecte dItem.Text
>> Line 86:
>> Line 87: 'Get the user details and fill
textboxes
>>
>> Source File: C:\Dev\Asset Register
>> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb Line: 85 >>
>> Stack Trace:
>>
>>
>> [NullReferenceEx ception: Object reference not set

to an
>> instance of an object.]
>>

AssetRegister .ViewUser.lstUs ers_SelectedInd exChanged
>> (Object sender, EventArgs e) in C:\Dev\Asset

Register
>> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb:85
>>
>>

System.Web.UI .WebControls.Li stControl.OnSel ectedIndexCha

ng
>> ed(EventArgs e)
>>
>>

System.Web.UI .WebControls.Li stBox.System.We b.UI.IPostBac kD
>> ataHandler.Rais ePostDataChange dEvent()
>> System.Web.UI.P age.RaiseChange dEvents()
>> System.Web.UI.P age.ProcessRequ estMain()
>>
>>
>>
>>
>>
>
>
>.
>
.

.

.

Nov 17 '05 #8

yop

-----Original Message-----
Yes it is a property. Here is the code that works fine onmy machine.....

Code behind >>>>>

Private Sub ListBox1_Select edIndexChanged( ByVal sender As System.Object, ByVal e As System.EventArg s)
Handles ListBox1.Select edIndexChanged
TextBox1.Text = ListBox1.Select edValue()
End Sub

ASPX code >>>>>

<HTML>
<HEAD>
<title>WebForm1 </title>
<meta name="GENERATOR " content="Micros oft
Visual Studio .NET 7.1">
<meta name="CODE_LANG UAGE" content="VisualBasic .NET 7.1">
<meta name="vs_defaul tClientScript"
content="JavaS cript">
<meta name="vs_target Schema"
content="htt p://schemas.microso ft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING= "GridLayout ">
<form id="Form1" method="post"
runat="server" >
<asp:ListBox id="ListBox1"
style="Z-INDEX: 101; LEFT: 288px; POSITION: absolute; TOP:168px"
runat="server"
Width="160px " Height="168px" AutoPostBack="T rue">
<asp:ListItem
Value="Tapasvi ">Tapasvi</asp:ListItem>
<asp:ListItem Value="Tap
at Work">Tap at Work</asp:ListItem>
</asp:ListBox>
<asp:TextBox id="TextBox1"
style="Z-INDEX: 102; LEFT: 288px; POSITION: absolute; TOP:120px"

runat="server"> </asp:TextBox>
</form>
</body>
</HTML>

Thanks,

Tap

-----Original Message-----
Aye it is set alright.

The SelectedValue is not a property of the listbox?
-----Original Message-----
Is the ListBox's AutoPostBack property set to True?

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
http://www.takempis.com
The more I learn, the less I know.

"yop" <yo*@oceanfree. net> wrote in message
news:04***** *************** ********@phx.gb l...
Kevin

I have an item selected alright, daft idea but could it be something to do with postback or something?

I click on the item and call the following:

Private Sub lstUsers_Select edIndexChanged( ByVal sender
As
Object, ByVal e As System.EventArg s) _
Handles

lstUsers.Sele ctedIndexChange d

'Need to bind the textboxes from the choice picked
out from the list
UserName.Text = lstUsers.Select edItem.Text
thanks

>-----Original Message-----
>Unless an Item has been selected, this value will be
null.
>
>--
>HTH,
>
>Kevin Spencer
>Microsoft MVP
>..Net Developer
>http://www.takempis.com
>The more I learn, the less I know.
>
>"yop" <yo*@oceanfree. net> wrote in message
>news:0a******* *************** ******@phx.gbl. ..
>> All
>>
>> When I try to get the text from my listbox I am get
an
>> error which is listed below.
>>
>> Any ideas?
>>
>> Thanks
>>
>> Object reference not set to an instance of an

object.
>> Description: An unhandled exception occurred
duringthe
>> execution of the current web request. Please
reviewthe
>> stack trace for more information about the error

and >> where it originated in the code.
>>
>> Exception Details: System.NullRefe renceException:
Object
>> reference not set to an instance of an object.
>>
>> Source Error:
>>
>>
>> Line 83: 'Need to bind the textboxes from

the
>> choice picked out from the list
>> Line 84: ' Dim ListItem As ListItem =
>> lstUsers.Select edItem
>> Line 85: UserName.Text =
stUsers.Selecte dItem.Text
>> Line 86:
>> Line 87: 'Get the user details and fill
textboxes
>>
>> Source File: C:\Dev\Asset Register
>> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb Line: 85 >>
>> Stack Trace:
>>
>>
>> [NullReferenceEx ception: Object reference not set

to an
>> instance of an object.]
>>

AssetRegister .ViewUser.lstUs ers_SelectedInd exChanged
>> (Object sender, EventArgs e) in C:\Dev\Asset

Register
>> SW\SourceCode\D otNet\ASP.NET\A SP.NET Asset
>> Register\AssetR egister\ViewUse rs.aspx.vb:85
>>
>>

System.Web.UI .WebControls.Li stControl.OnSel ectedIndexCha

ng
>> ed(EventArgs e)
>>
>>

System.Web.UI .WebControls.Li stBox.System.We b.UI.IPostBac kD
>> ataHandler.Rais ePostDataChange dEvent()
>> System.Web.UI.P age.RaiseChange dEvents()
>> System.Web.UI.P age.ProcessRequ estMain()
>>
>>
>>
>>
>>
>
>
>.
>
.

.

.

Nov 17 '05 #9

yop

eventually found the fix after trawling the forums!!

"I was loading the listbox dynamically on the page_load
event.
Eventually I discovered - that was too late,
The items showed on the page but weren't really
there..... (figure that one
out)
When I moved the list populate routine to the page_init
event everything
worked great."

Thanks for all your help

-----Original Message-----
All

When I try to get the text from my listbox I am get an
error which is listed below.

Any ideas?

Thanks

Object reference not set to an instance of an object.
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.NullRefe renceException: Object
reference not set to an instance of an object.

Source Error:
Line 83: 'Need to bind the textboxes from the
choice picked out from the list
Line 84: ' Dim ListItem As ListItem =
lstUsers.Selec tedItem
Line 85: UserName.Text = stUsers.Selecte dItem.TextLine 86:
Line 87: 'Get the user details and fill textboxes

Source File: C:\Dev\Asset Register
SW\SourceCode\ DotNet\ASP.NET\ ASP.NET Asset
Register\Asset Register\ViewUs ers.aspx.vb Line: 85

Stack Trace:
[NullReferenceEx ception: Object reference not set to an
instance of an object.]
AssetRegister.V iewUser.lstUser s_SelectedIndex Changed
(Object sender, EventArgs e) in C:\Dev\Asset Register
SW\SourceCode\ DotNet\ASP.NET\ ASP.NET Asset
Register\Asset Register\ViewUs ers.aspx.vb:85

System.Web.UI. WebControls.Lis tControl.OnSele ctedIndexChan ged(EventArgs e)

System.Web.UI. WebControls.Lis tBox.System.Web .UI.IPostBack DataHandler.Rai sePostDataChang edEvent()
System.Web.UI.P age.RaiseChange dEvents()
System.Web.UI.P age.ProcessRequ estMain()

.

Nov 17 '05 #10

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