Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
DataGrid1.DataBind()
End Sub
When I click the button, I would have thought that the datagrid would keep
increasing with the values "2,", "Jason", "1", but it doesn't.
I believe I have what is called a disconnected dataset, and I need the user
to work on a dataset before they post the final values to the server, hence
why I'm not using a SQL Adapter.
Can someone PLEASE explain why the above won't work, and how to work with
disconnected datasets.
TIA
5  1026 
J,
Every time you load your page the dataset is being recreated. You need to
either first save the new row to the database or only get the dataset the
first page load and then store it in memory (a session variable or the like)
between page views.
Since the web is a stateless environment (all objects are destroyed after
rendering a page) you have to take measures to store the objects you need to
remain between posts.
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at: www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message news:eg**************@tk2msftngp13.phx.gbl... Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
DataGrid1.DataBind()
End Sub
When I click the button, I would have thought that the datagrid would keep
increasing with the values "2,", "Jason", "1", but it doesn't.
I believe I have what is called a disconnected dataset, and I need the
user to work on a dataset before they post the final values to the server,
hence why I'm not using a SQL Adapter.
Can someone PLEASE explain why the above won't work, and how to work with
disconnected datasets.
TIA
A session variable!!
How would I store the dataset as a session variable?
Would it be simply session("Temp")=dsTest.tables("TestTable")
TIA
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:uU**************@tk2msftngp13.phx.gbl... J,
Every time you load your page the dataset is being recreated. You need to
either first save the new row to the database or only get the dataset the
first page load and then store it in memory (a session variable or the
like) between page views.
Since the web is a stateless environment (all objects are destroyed after
rendering a page) you have to take measures to store the objects you need
to remain between posts.
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at:
www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message
news:eg**************@tk2msftngp13.phx.gbl... Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
DataGrid1.DataBind()
End Sub
When I click the button, I would have thought that the datagrid would
keep increasing with the values "2,", "Jason", "1", but it doesn't.
I believe I have what is called a disconnected dataset, and I need the
user to work on a dataset before they post the final values to the server,
hence why I'm not using a SQL Adapter.
Can someone PLEASE explain why the above won't work, and how to work
with disconnected datasets.
TIA
J,
You have to both store the datatable in the session variable and get it out
again when you go to use it.
Change your code to this: (I've put '********* above the new lines of code.)
'Put user code to initialize the page here
ip() '*******Move this (It should only fire the first page load)
dsTest = Session("Temp") '***********Move this (It should only be done on
post back)
If Not IsPostBack Then
ip() '*******Moved here.
DataGrid1.DataBind()
Else
dsTest = Session("Temp")
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest '*********Add the datatable to the session
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at: www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message news:ew**************@TK2MSFTNGP10.phx.gbl... Well My code now looks like...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
dsTest = Session("Temp")
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
And I'm getting an error saying...
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.NullReferenceException: Object reference not set
to an instance of an object.
Source Error:
Line 74: Private Sub Button1_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Button1.Click
Line 75: Dim newrow As DataRow
Line 76: newrow = dsTest.Tables("TestTable").NewRow
Line 77: newrow(0) = "2"
Line 78: newrow(1) = "Jason"
Source File: c:\inetpub\wwwroot\hbitl_umc\test.aspx.vb Line: 76
Am I really doing this right?
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:#k**************@TK2MSFTNGP09.phx.gbl... Well, your code is storing just the table itself not the whole dataset
(I think that's all you need for your purposes here, but yes, that's it!
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at:
www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message
news:eO*************@tk2msftngp13.phx.gbl... A session variable!!
How would I store the dataset as a session variable?
Would it be simply session("Temp")=dsTest.tables("TestTable")
TIA
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:uU**************@tk2msftngp13.phx.gbl...
> J,
>
> Every time you load your page the dataset is being recreated. You
need to > either first save the new row to the database or only get the
dataset the > first page load and then store it in memory (a session variable or
the like)
> between page views.
>
> Since the web is a stateless environment (all objects are destroyed
after > rendering a page) you have to take measures to store the objects you
need to
> remain between posts.
>
> Sincerely,
>
> --
> S. Justin Gengo, MCP
> Web Developer
>
> Free code library at:
> www.aboutfortunate.com
>
> "Out of chaos comes order."
> Nietzche
>
>
> "J" <nospam> wrote in message
news:eg**************@tk2msftngp13.phx.gbl...
> > Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
> > System.EventArgs) Handles MyBase.Load
> >
> > 'Put user code to initialize the page here
> >
> > ip()
> >
> > If Not IsPostBack Then
> >
> > DataGrid1.DataBind()
> >
> > End If
> >
> > End Sub
> >
> > Sub ip()
> >
> > Dim newrow As DataRow
> >
> >
> >
> >
> >
> > SqlConnection1.Open()
> >
> > SqlCommand1.Parameters("@members").Value = "1007,4200,999"
> >
> > daTest.SelectCommand = SqlCommand1
> >
> > daTest.Fill(dsTest, "TestTable")
> >
> > Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
> > DataViewRowState.CurrentRows)
> >
> > DataGrid1.DataSource = dvTest
> >
> > newrow = dsTest.Tables("TestTable").NewRow
> >
> > newrow(0) = "1"
> >
> > newrow(1) = "Jason"
> >
> > newrow(2) = "1"
> >
> > dsTest.Tables("TestTable").Rows.Add(newrow)
> >
> > dsTest.AcceptChanges()
> >
> > End Sub
> >
> > Private Sub Button1_Click(ByVal sender As System.Object, ByVal e
As > > System.EventArgs) Handles Button1.Click
> >
> > Dim newrow As DataRow
> >
> > newrow = dsTest.Tables("TestTable").NewRow
> >
> > newrow(0) = "2"
> >
> > newrow(1) = "Jason"
> >
> > newrow(2) = "1"
> >
> > dsTest.Tables("TestTable").Rows.Add(newrow)
> >
> > dsTest.AcceptChanges()
> >
> > DataGrid1.DataBind()
> >
> > End Sub
> >
> >
> >
> > When I click the button, I would have thought that the datagrid
would keep
> > increasing with the values "2,", "Jason", "1", but it doesn't.
> >
> > I believe I have what is called a disconnected dataset, and I need the > user
> > to work on a dataset before they post the final values to the server, > hence
> > why I'm not using a SQL Adapter.
> >
> > Can someone PLEASE explain why the above won't work, and how to
work with
> > disconnected datasets.
> >
> > TIA
> >
> >
> >
> >
> >
>
>
Well, I've changed the code accordingly, it now looks like...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
If Not IsPostBack Then
ip()
DataGrid1.DataBind()
Else
dsTest = Session("Temp")
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,9999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
When I run, and click the button, the datagrid disappears.
When I click it a second time, I'm told ...
Specified cast is not valid.
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.InvalidCastException: Specified cast is not valid.
Source Error:
Line 49: DataGrid1.DataBind()
Line 50: Else
Line 51: dsTest = Session("Temp")
Line 52: End If
Line 53:
Source File: c:\inetpub\wwwroot\hbitl_umc\test.aspx.vb Line: 51
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:#E**************@TK2MSFTNGP10.phx.gbl... J,
You have to both store the datatable in the session variable and get it
out again when you go to use it.
Change your code to this: (I've put '********* above the new lines of
code.)
'Put user code to initialize the page here
ip() '*******Move this (It should only fire the first page load)
dsTest = Session("Temp") '***********Move this (It should only be done on
post back)
If Not IsPostBack Then
ip() '*******Moved here.
DataGrid1.DataBind()
Else
dsTest = Session("Temp")
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest '*********Add the datatable to the session
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at:
www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message
news:ew**************@TK2MSFTNGP10.phx.gbl... Well My code now looks like...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
dsTest = Session("Temp")
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
And I'm getting an error saying...
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.NullReferenceException: Object reference not
set to an instance of an object.
Source Error:
Line 74: Private Sub Button1_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Button1.Click
Line 75: Dim newrow As DataRow
Line 76: newrow = dsTest.Tables("TestTable").NewRow
Line 77: newrow(0) = "2"
Line 78: newrow(1) = "Jason"
Source File: c:\inetpub\wwwroot\hbitl_umc\test.aspx.vb Line: 76
Am I really doing this right?
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:#k**************@TK2MSFTNGP09.phx.gbl... Well, your code is storing just the table itself not the whole dataset (I think that's all you need for your purposes here, but yes, that's it!
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at:
www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message news:eO*************@tk2msftngp13.phx.gbl... > A session variable!!
>
> How would I store the dataset as a session variable?
>
> Would it be simply session("Temp")=dsTest.tables("TestTable")
>
> TIA
>
> "S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
> news:uU**************@tk2msftngp13.phx.gbl...
> > J,
> >
> > Every time you load your page the dataset is being recreated. You need to
> > either first save the new row to the database or only get the dataset the
> > first page load and then store it in memory (a session variable or the > like)
> > between page views.
> >
> > Since the web is a stateless environment (all objects are
destroyed after
> > rendering a page) you have to take measures to store the objects
you need
> to
> > remain between posts.
> >
> > Sincerely,
> >
> > --
> > S. Justin Gengo, MCP
> > Web Developer
> >
> > Free code library at:
> > www.aboutfortunate.com
> >
> > "Out of chaos comes order."
> > Nietzche
> >
> >
> > "J" <nospam> wrote in message
> news:eg**************@tk2msftngp13.phx.gbl...
> > > Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
> > > System.EventArgs) Handles MyBase.Load
> > >
> > > 'Put user code to initialize the page here
> > >
> > > ip()
> > >
> > > If Not IsPostBack Then
> > >
> > > DataGrid1.DataBind()
> > >
> > > End If
> > >
> > > End Sub
> > >
> > > Sub ip()
> > >
> > > Dim newrow As DataRow
> > >
> > >
> > >
> > >
> > >
> > > SqlConnection1.Open()
> > >
> > > SqlCommand1.Parameters("@members").Value = "1007,4200,999"
> > >
> > > daTest.SelectCommand = SqlCommand1
> > >
> > > daTest.Fill(dsTest, "TestTable")
> > >
> > > Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
> > > DataViewRowState.CurrentRows)
> > >
> > > DataGrid1.DataSource = dvTest
> > >
> > > newrow = dsTest.Tables("TestTable").NewRow
> > >
> > > newrow(0) = "1"
> > >
> > > newrow(1) = "Jason"
> > >
> > > newrow(2) = "1"
> > >
> > > dsTest.Tables("TestTable").Rows.Add(newrow)
> > >
> > > dsTest.AcceptChanges()
> > >
> > > End Sub
> > >
> > > Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As > > > System.EventArgs) Handles Button1.Click
> > >
> > > Dim newrow As DataRow
> > >
> > > newrow = dsTest.Tables("TestTable").NewRow
> > >
> > > newrow(0) = "2"
> > >
> > > newrow(1) = "Jason"
> > >
> > > newrow(2) = "1"
> > >
> > > dsTest.Tables("TestTable").Rows.Add(newrow)
> > >
> > > dsTest.AcceptChanges()
> > >
> > > DataGrid1.DataBind()
> > >
> > > End Sub
> > >
> > >
> > >
> > > When I click the button, I would have thought that the datagrid
would > keep
> > > increasing with the values "2,", "Jason", "1", but it doesn't.
> > >
> > > I believe I have what is called a disconnected dataset, and I
need the > > user
> > > to work on a dataset before they post the final values to the
server, > > hence
> > > why I'm not using a SQL Adapter.
> > >
> > > Can someone PLEASE explain why the above won't work, and how to
work > with
> > > disconnected datasets.
> > >
> > > TIA
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>
J,
It's because the datasource of your table is actually the dataview. Inside
of the button click's event handler you need to recreate the dataview and
set it as the datasource of the grid before you rebind the grid.
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at: www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message news:Oj**************@TK2MSFTNGP09.phx.gbl... Well, I've changed the code accordingly, it now looks like...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
If Not IsPostBack Then
ip()
DataGrid1.DataBind()
Else
dsTest = Session("Temp")
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,9999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
When I run, and click the button, the datagrid disappears.
When I click it a second time, I'm told ...
Specified cast is not valid.
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.InvalidCastException: Specified cast is not
valid.
Source Error:
Line 49: DataGrid1.DataBind()
Line 50: Else
Line 51: dsTest = Session("Temp")
Line 52: End If
Line 53:
Source File: c:\inetpub\wwwroot\hbitl_umc\test.aspx.vb Line: 51
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:#E**************@TK2MSFTNGP10.phx.gbl... J,
You have to both store the datatable in the session variable and get it
out again when you go to use it.
Change your code to this: (I've put '********* above the new lines of
code.)
'Put user code to initialize the page here
ip() '*******Move this (It should only fire the first page load)
dsTest = Session("Temp") '***********Move this (It should only be done
on post back)
If Not IsPostBack Then
ip() '*******Moved here.
DataGrid1.DataBind()
Else
dsTest = Session("Temp")
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest '*********Add the datatable to the session
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
Sincerely,
--
S. Justin Gengo, MCP
Web Developer
Free code library at:
www.aboutfortunate.com
"Out of chaos comes order."
Nietzche
"J" <nospam> wrote in message
news:ew**************@TK2MSFTNGP10.phx.gbl... Well My code now looks like...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
ip()
dsTest = Session("Temp")
If Not IsPostBack Then
DataGrid1.DataBind()
End If
End Sub
Sub ip()
Dim newrow As DataRow
SqlConnection1.Open()
SqlCommand1.Parameters("@members").Value = "1007,4200,999"
daTest.SelectCommand = SqlCommand1
daTest.Fill(dsTest, "TestTable")
Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
DataViewRowState.CurrentRows)
DataGrid1.DataSource = dvTest
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "1"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
Dim newrow As DataRow
newrow = dsTest.Tables("TestTable").NewRow
newrow(0) = "2"
newrow(1) = "Jason"
newrow(2) = "1"
dsTest.Tables("TestTable").Rows.Add(newrow)
dsTest.AcceptChanges()
Session("Temp") = dsTest.Tables("TestTable")
DataGrid1.DataBind()
End Sub
And I'm getting an error saying...
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.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
Line 74: Private Sub Button1_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Button1.Click
Line 75: Dim newrow As DataRow
Line 76: newrow = dsTest.Tables("TestTable").NewRow
Line 77: newrow(0) = "2"
Line 78: newrow(1) = "Jason"
Source File: c:\inetpub\wwwroot\hbitl_umc\test.aspx.vb Line: 76
Am I really doing this right?
"S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
news:#k**************@TK2MSFTNGP09.phx.gbl...
> Well, your code is storing just the table itself not the whole
dataset (I > think that's all you need for your purposes here, but yes, that's
it! >
> Sincerely,
>
> --
> S. Justin Gengo, MCP
> Web Developer
>
> Free code library at:
> www.aboutfortunate.com
>
> "Out of chaos comes order."
> Nietzche
>
>
> "J" <nospam> wrote in message
news:eO*************@tk2msftngp13.phx.gbl... > > A session variable!!
> >
> > How would I store the dataset as a session variable?
> >
> > Would it be simply session("Temp")=dsTest.tables("TestTable")
> >
> > TIA
> >
> > "S. Justin Gengo" <sj*****@aboutfortunate.com> wrote in message
> > news:uU**************@tk2msftngp13.phx.gbl...
> > > J,
> > >
> > > Every time you load your page the dataset is being recreated.
You need > to
> > > either first save the new row to the database or only get the
dataset > the
> > > first page load and then store it in memory (a session variable
or the > > like)
> > > between page views.
> > >
> > > Since the web is a stateless environment (all objects are destroyed > after
> > > rendering a page) you have to take measures to store the objects you > need
> > to
> > > remain between posts.
> > >
> > > Sincerely,
> > >
> > > --
> > > S. Justin Gengo, MCP
> > > Web Developer
> > >
> > > Free code library at:
> > > www.aboutfortunate.com
> > >
> > > "Out of chaos comes order."
> > > Nietzche
> > >
> > >
> > > "J" <nospam> wrote in message
> > news:eg**************@tk2msftngp13.phx.gbl...
> > > > Private Sub Page_Load(ByVal sender As System.Object, ByVal e
As > > > > System.EventArgs) Handles MyBase.Load
> > > >
> > > > 'Put user code to initialize the page here
> > > >
> > > > ip()
> > > >
> > > > If Not IsPostBack Then
> > > >
> > > > DataGrid1.DataBind()
> > > >
> > > > End If
> > > >
> > > > End Sub
> > > >
> > > > Sub ip()
> > > >
> > > > Dim newrow As DataRow
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > SqlConnection1.Open()
> > > >
> > > > SqlCommand1.Parameters("@members").Value = "1007,4200,999"
> > > >
> > > > daTest.SelectCommand = SqlCommand1
> > > >
> > > > daTest.Fill(dsTest, "TestTable")
> > > >
> > > > Dim dvTest As New DataView(dsTest.Tables("TestTable"), "", "",
> > > > DataViewRowState.CurrentRows)
> > > >
> > > > DataGrid1.DataSource = dvTest
> > > >
> > > > newrow = dsTest.Tables("TestTable").NewRow
> > > >
> > > > newrow(0) = "1"
> > > >
> > > > newrow(1) = "Jason"
> > > >
> > > > newrow(2) = "1"
> > > >
> > > > dsTest.Tables("TestTable").Rows.Add(newrow)
> > > >
> > > > dsTest.AcceptChanges()
> > > >
> > > > End Sub
> > > >
> > > > Private Sub Button1_Click(ByVal sender As System.Object, ByVal
e As > > > > System.EventArgs) Handles Button1.Click
> > > >
> > > > Dim newrow As DataRow
> > > >
> > > > newrow = dsTest.Tables("TestTable").NewRow
> > > >
> > > > newrow(0) = "2"
> > > >
> > > > newrow(1) = "Jason"
> > > >
> > > > newrow(2) = "1"
> > > >
> > > > dsTest.Tables("TestTable").Rows.Add(newrow)
> > > >
> > > > dsTest.AcceptChanges()
> > > >
> > > > DataGrid1.DataBind()
> > > >
> > > > End Sub
> > > >
> > > >
> > > >
> > > > When I click the button, I would have thought that the
datagrid would
> > keep
> > > > increasing with the values "2,", "Jason", "1", but it doesn't.
> > > >
> > > > I believe I have what is called a disconnected dataset, and I
need the
> > > user
> > > > to work on a dataset before they post the final values to the
server,
> > > hence
> > > > why I'm not using a SQL Adapter.
> > > >
> > > > Can someone PLEASE explain why the above won't work, and how
to work > > with
> > > > disconnected datasets.
> > > >
> > > > TIA
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
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