load a droplist in VB when the edit is clicked in a datagrid

[Stanley J Mroczek]

I am trying to load a droplist in VB when the edit is clicked in a datagrid.
I tried to use OnDataBinding and loading the droplist in subroutine "loaddd".
I get this error Object reference not set to an instance of an object.

Here is the code:

<asp:TemplateCo lumn runat="server" HeaderText="Id Type Option"
SortExpression= "IdTypeOpti on">
<itemtemplate >
<asp:label runat="server" Text='<%# DataBinder.Eval (Container.Data Item,
"TypeOption ") %>' />
<asp:label runat="server" ID="LlbTypeOpti on" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>'/>
</itemtemplate>
<EditItemTempla te>
<asp:dropdownli st id="deViews" OnDataBinding=" loaddd"
runat="server"> </asp:dropdownlis t>
<asp:label runat="server" ID="IdTypeOptio n" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>' />
</EditItemTemplat e>
</asp:TemplateCol umn>
Sub loaddd(ByVal sender As Object, ByVal e As System.EventArg s)

Dim myConnection As SqlConnection = New
SqlConnection(C onfigurationSet tings.AppSettin gs("ConnectionS tring"))
Dim myCommand As SqlCommand = New
SqlCommand("Get _All_TypeofOpti ons", myConnection)

Dim dtrControlOptio n As New DataTable
Dim dropRowOption As DataRow

dtrControlOptio n.Columns.Add( _
New DataColumn("Typ eOption", GetType(String) ))

dtrControlOptio n.Columns.Add( _
New DataColumn("IdT ypeOption", GetType(String) ))

myConnection.Op en()

Dim Optionfile As SqlDataReader =
myCommand.Execu teReader(Comman dBehavior.Close Connection)

While Optionfile.Read ()
dropRowOption = dtrControlOptio n.NewRow()
dropRowOption(" TypeOption") = Optionfile.Item ("TypeOption ")
dropRowOption(" IdTypeOption") = Optionfile.Item ("IdTypeOption" )
dtrControlOptio n.Rows.Add(drop RowOption)

End While

deViews.DataSou rce = dtrControlOptio n
deViews.DataTex tField = "TypeOption "
deViews.DataVal ueField = "IdTypeOpti on"
deViews.DataBin d()

myConnection.Cl ose()
BindOption()
Dim i As Integer
For i = 0 To deViews.Items.C ount - 1
Dim opchk As String = deViews.Items(i ).Value
Dim chk = deViews.DataVal ueField
If opchk = Session("typeof option") Then
deViews.Items(i ).Selected = True
End If
Next

End Sub

[pm]

On what line does the error occur?

"Stanley J Mroczek" wrote:

I am trying to load a droplist in VB when the edit is clicked in a datagrid.
I tried to use OnDataBinding and loading the droplist in subroutine "loaddd".
I get this error Object reference not set to an instance of an object.

Here is the code:

<asp:TemplateCo lumn runat="server" HeaderText="Id Type Option"
SortExpression= "IdTypeOpti on">
<itemtemplate >
<asp:label runat="server" Text='<%# DataBinder.Eval (Container.Data Item,
"TypeOption ") %>' />
<asp:label runat="server" ID="LlbTypeOpti on" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>'/>
</itemtemplate>
<EditItemTempla te>
<asp:dropdownli st id="deViews" OnDataBinding=" loaddd"
runat="server"> </asp:dropdownlis t>
<asp:label runat="server" ID="IdTypeOptio n" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>' />
</EditItemTemplat e>
</asp:TemplateCol umn>
Sub loaddd(ByVal sender As Object, ByVal e As System.EventArg s)

Dim myConnection As SqlConnection = New
SqlConnection(C onfigurationSet tings.AppSettin gs("ConnectionS tring"))
Dim myCommand As SqlCommand = New
SqlCommand("Get _All_TypeofOpti ons", myConnection)

Dim dtrControlOptio n As New DataTable
Dim dropRowOption As DataRow

dtrControlOptio n.Columns.Add( _
New DataColumn("Typ eOption", GetType(String) ))

dtrControlOptio n.Columns.Add( _
New DataColumn("IdT ypeOption", GetType(String) ))

myConnection.Op en()

Dim Optionfile As SqlDataReader =
myCommand.Execu teReader(Comman dBehavior.Close Connection)

While Optionfile.Read ()
dropRowOption = dtrControlOptio n.NewRow()
dropRowOption(" TypeOption") = Optionfile.Item ("TypeOption ")
dropRowOption(" IdTypeOption") = Optionfile.Item ("IdTypeOption" )
dtrControlOptio n.Rows.Add(drop RowOption)

End While

deViews.DataSou rce = dtrControlOptio n
deViews.DataTex tField = "TypeOption "
deViews.DataVal ueField = "IdTypeOpti on"
deViews.DataBin d()

myConnection.Cl ose()
BindOption()
Dim i As Integer
For i = 0 To deViews.Items.C ount - 1
Dim opchk As String = deViews.Items(i ).Value
Dim chk = deViews.DataVal ueField
If opchk = Session("typeof option") Then
deViews.Items(i ).Selected = True
End If
Next

End Sub

[Stanley J Mroczek]

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 211: End While
Line 212:
Line 213: deViews.DataSou rce = dtrControlOptio n
Line 214: deViews.DataTex tField = "TypeOption "
Line 215: deViews.DataVal ueField = "IdTypeOpti on"
Source File: C:\best\_Option Maint.ascx.vb Line: 213

"pm" wrote:

On what line does the error occur?

"Stanley J Mroczek" wrote:

I am trying to load a droplist in VB when the edit is clicked in a datagrid.
I tried to use OnDataBinding and loading the droplist in subroutine "loaddd".
I get this error Object reference not set to an instance of an object.

Here is the code:

<asp:TemplateCo lumn runat="server" HeaderText="Id Type Option"
SortExpression= "IdTypeOpti on">
<itemtemplate >
<asp:label runat="server" Text='<%# DataBinder.Eval (Container.Data Item,
"TypeOption ") %>' />
<asp:label runat="server" ID="LlbTypeOpti on" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>'/>
</itemtemplate>
<EditItemTempla te>
<asp:dropdownli st id="deViews" OnDataBinding=" loaddd"
runat="server"> </asp:dropdownlis t>
<asp:label runat="server" ID="IdTypeOptio n" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>' />
</EditItemTemplat e>
</asp:TemplateCol umn>
Sub loaddd(ByVal sender As Object, ByVal e As System.EventArg s)

Dim myConnection As SqlConnection = New
SqlConnection(C onfigurationSet tings.AppSettin gs("ConnectionS tring"))
Dim myCommand As SqlCommand = New
SqlCommand("Get _All_TypeofOpti ons", myConnection)

Dim dtrControlOptio n As New DataTable
Dim dropRowOption As DataRow

dtrControlOptio n.Columns.Add( _
New DataColumn("Typ eOption", GetType(String) ))

dtrControlOptio n.Columns.Add( _
New DataColumn("IdT ypeOption", GetType(String) ))

myConnection.Op en()

Dim Optionfile As SqlDataReader =
myCommand.Execu teReader(Comman dBehavior.Close Connection)

While Optionfile.Read ()
dropRowOption = dtrControlOptio n.NewRow()
dropRowOption(" TypeOption") = Optionfile.Item ("TypeOption ")
dropRowOption(" IdTypeOption") = Optionfile.Item ("IdTypeOption" )
dtrControlOptio n.Rows.Add(drop RowOption)

End While

deViews.DataSou rce = dtrControlOptio n
deViews.DataTex tField = "TypeOption "
deViews.DataVal ueField = "IdTypeOpti on"
deViews.DataBin d()

myConnection.Cl ose()
BindOption()
Dim i As Integer
For i = 0 To deViews.Items.C ount - 1
Dim opchk As String = deViews.Items(i ).Value
Dim chk = deViews.DataVal ueField
If opchk = Session("typeof option") Then
deViews.Items(i ).Selected = True
End If
Next

End Sub

[pm]

Once a control is in a grid you can't address it using its id but have to get
a reference to it using FindControl.

This is close to what you need to do but you will have to play around with
it a bit (its in C# sorry.

DropDownList tmpDDL = new DropDownList();
tmpDDL = e.Item.FindCont rol("deViews");
if (tmpDDL!=null) //here for testing mostly
{
.. . . manipulate the dataview
}

Don't forget that at the beginning of your load event you want to check if
you are on an Item or Alternating Item (hence the if (tmpDDL!=null). You
won't be able to find the DropDownList on the Header and the Footer. There
is an enum for ItemTypes you can use.
Let me know how it goes.

"Stanley J Mroczek" wrote:

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 211: End While
Line 212:
Line 213: deViews.DataSou rce = dtrControlOptio n
Line 214: deViews.DataTex tField = "TypeOption "
Line 215: deViews.DataVal ueField = "IdTypeOpti on"
Source File: C:\best\_Option Maint.ascx.vb Line: 213

"pm" wrote:

On what line does the error occur?

"Stanley J Mroczek" wrote:

I am trying to load a droplist in VB when the edit is clicked in a datagrid.
I tried to use OnDataBinding and loading the droplist in subroutine "loaddd".
I get this error Object reference not set to an instance of an object.

Here is the code:

<asp:TemplateCo lumn runat="server" HeaderText="Id Type Option"
SortExpression= "IdTypeOpti on">
<itemtemplate >
<asp:label runat="server" Text='<%# DataBinder.Eval (Container.Data Item,
"TypeOption ") %>' />
<asp:label runat="server" ID="LlbTypeOpti on" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>'/>
</itemtemplate>
<EditItemTempla te>
<asp:dropdownli st id="deViews" OnDataBinding=" loaddd"
runat="server"> </asp:dropdownlis t>
<asp:label runat="server" ID="IdTypeOptio n" Visible=False Text='<%#
DataBinder.Eval (Container.Data Item, "IdTypeOpti on") %>' />
</EditItemTemplat e>
</asp:TemplateCol umn>
Sub loaddd(ByVal sender As Object, ByVal e As System.EventArg s)

Dim myConnection As SqlConnection = New
SqlConnection(C onfigurationSet tings.AppSettin gs("ConnectionS tring"))
Dim myCommand As SqlCommand = New
SqlCommand("Get _All_TypeofOpti ons", myConnection)

Dim dtrControlOptio n As New DataTable
Dim dropRowOption As DataRow

dtrControlOptio n.Columns.Add( _
New DataColumn("Typ eOption", GetType(String) ))

dtrControlOptio n.Columns.Add( _
New DataColumn("IdT ypeOption", GetType(String) ))

myConnection.Op en()

Dim Optionfile As SqlDataReader =
myCommand.Execu teReader(Comman dBehavior.Close Connection)

While Optionfile.Read ()
dropRowOption = dtrControlOptio n.NewRow()
dropRowOption(" TypeOption") = Optionfile.Item ("TypeOption ")
dropRowOption(" IdTypeOption") = Optionfile.Item ("IdTypeOption" )
dtrControlOptio n.Rows.Add(drop RowOption)

End While

deViews.DataSou rce = dtrControlOptio n
deViews.DataTex tField = "TypeOption "
deViews.DataVal ueField = "IdTypeOpti on"
deViews.DataBin d()

myConnection.Cl ose()
BindOption()
Dim i As Integer
For i = 0 To deViews.Items.C ount - 1
Dim opchk As String = deViews.Items(i ).Value
Dim chk = deViews.DataVal ueField
If opchk = Session("typeof option") Then
deViews.Items(i ).Selected = True
End If
Next

End Sub