Hi,
I dont see any line of code with an error. What i would suggest
is to place a break point in the start of each procedure in the columnstyle.
Step through the code line by line until you find the error.
Ken
----------------
"Ron L" <ro**@bogus.Address.com> wrote in message
news:%2****************@TK2MSFTNGP15.phx.gbl...
Ken
Thanks for the response. I forgot to mention that this is the code from
Ken Shepard's
www.syncfusion.com site, the data grid bound combo box column.
Here it is.
Ron L
' DataGridComboBoxColumn.vb - From George Shepard's
www.syncfusion.com site.
(The bound
' data grid combo box example.)
Option Strict Off
Option Explicit On
Imports Microsoft.VisualBasic
Imports System
Imports System.ComponentModel
Imports System.Data
Imports System.Data.Common
Imports System.Data.OleDb
Imports System.Drawing
Imports System.Windows.Forms
' Step 1. Derive a custom column style from DataGridTextBoxColumn
' a) add a ComboBox member
' b) track when the combobox has focus in Enter and Leave events
' c) override Edit to allow the ComboBox to replace the TextBox
' d) override Commit to save the changed data
Public Class DataGridComboBoxColumn
Inherits DataGridTextBoxColumn
Public ColumnComboBox As NoKeyUpCombo
Private _source As System.Windows.Forms.CurrencyManager
Private _rowNum As Integer
Private _isEditing As Boolean
Public Shared _RowCount As Integer
Public Sub New()
_source = Nothing
_isEditing = False
_RowCount = -1
ColumnComboBox = New NoKeyUpCombo()
ColumnComboBox.DropDownStyle = ComboBoxStyle.DropDownList
AddHandler ColumnComboBox.Leave, AddressOf LeaveComboBox
AddHandler ColumnComboBox.SelectionChangeCommitted, AddressOf
ComboStartEditing
End Sub 'New
Private Sub HandleScroll(ByVal sender As Object, ByVal e As
EventArgs)
If ColumnComboBox.Visible Then
ColumnComboBox.Hide()
End If
End Sub 'HandleScroll
Private Sub ComboStartEditing(ByVal sender As Object, ByVal e As
EventArgs)
_isEditing = True
MyBase.ColumnStartedEditing(sender)
End Sub 'ComboMadeCurrent
Private Sub LeaveComboBox(ByVal sender As Object, ByVal e As
EventArgs)
If _isEditing Then
SetColumnValueAtRow(_source, _rowNum, ColumnComboBox.Text)
_isEditing = False
Invalidate()
End If
ColumnComboBox.Hide()
AddHandler Me.DataGridTableStyle.DataGrid.Scroll, New
EventHandler(AddressOf HandleScroll)
End Sub 'LeaveComboBox
Protected Overloads Overrides Sub Edit(ByVal [source] As
System.Windows.Forms.CurrencyManager, ByVal rowNum As Integer, ByVal bounds
As System.Drawing.Rectangle, ByVal [readOnly] As Boolean, ByVal instantText
As String, ByVal cellIsVisible As Boolean)
MyBase.Edit([source], rowNum, bounds, [readOnly], instantText,
cellIsVisible)
_rowNum = rowNum
_source = [source]
ColumnComboBox.Parent = Me.TextBox.Parent
ColumnComboBox.Location = Me.TextBox.Location
ColumnComboBox.Size = New Size(Me.TextBox.Size.Width,
ColumnComboBox.Size.Height)
ColumnComboBox.SelectedIndex =
ColumnComboBox.FindStringExact(Me.TextBox.Text)
ColumnComboBox.Text = Me.TextBox.Text
Me.TextBox.Visible = False
ColumnComboBox.Visible = True
AddHandler Me.DataGridTableStyle.DataGrid.Scroll, AddressOf
HandleScroll
ColumnComboBox.BringToFront()
ColumnComboBox.Focus()
End Sub 'Edit
Protected Overrides Function Commit(ByVal dataSource As
System.Windows.Forms.CurrencyManager, ByVal rowNum As Integer) As Boolean
If _isEditing Then
_isEditing = False
SetColumnValueAtRow(dataSource, rowNum, ColumnComboBox.Text)
End If
Return True
End Function 'Commit
Protected Overrides Sub ConcedeFocus()
Console.WriteLine("ConcedeFocus")
MyBase.ConcedeFocus()
End Sub 'ConcedeFocus
Protected Overrides Function GetColumnValueAtRow(ByVal [source] As
System.Windows.Forms.CurrencyManager, ByVal rowNum As Integer) As Object
Dim s As Object = MyBase.GetColumnValueAtRow([source], rowNum)
Dim dv As DataView = CType(Me.ColumnComboBox.DataSource,
DataView)
Dim rowCount As Integer = dv.Count
Dim i As Integer = 0
Dim s1 As Object
'if things are slow, you could order your dataview
'& use binary search instead of this linear one
While i < rowCount
s1 = dv(i)(Me.ColumnComboBox.ValueMember)
If (Not s1 Is DBNull.Value) AndAlso _
(Not s Is DBNull.Value) AndAlso _
s = s1 Then
Exit While
End If
i = i + 1
End While
If i < rowCount Then
Return dv(i)(Me.ColumnComboBox.DisplayMember)
End If
Return DBNull.Value
End Function 'GetColumnValueAtRow
Protected Overrides Sub SetColumnValueAtRow(ByVal [source] As
System.Windows.Forms.CurrencyManager, ByVal rowNum As Integer, ByVal value
As Object)
Dim s As Object = value
Dim dv As DataView = CType(Me.ColumnComboBox.DataSource,
DataView)
Dim rowCount As Integer = dv.Count
Dim i As Integer = 0
Dim s1 As Object
'if things are slow, you could order your dataview
'& use binary search instead of this linear one
While i < rowCount
s1 = dv(i)(Me.ColumnComboBox.DisplayMember)
If (Not s1 Is DBNull.Value) AndAlso _
s = s1 Then
Exit While
End If
i = i + 1
End While
If i < rowCount Then
s = dv(i)(Me.ColumnComboBox.ValueMember)
Else
s = DBNull.Value
End If
MyBase.SetColumnValueAtRow([source], rowNum, s)
End Sub 'SetColumnValueAtRow
End Class 'DataGridComboBoxColumn
"Ken Tucker [MVP]" <vb***@bellsouth.net> wrote in message
news:ut**************@tk2msftngp13.phx.gbl...
Hi,
Post the code for the column style
Ken
----------------
"Ron L" <ro**@bogus.Address.com> wrote in message
news:uk*************@TK2MSFTNGP10.phx.gbl...
I have a dataset whose source is a SQL 2k stored procedure that I am
trying
to display in a datagrid. This datasource has 4 columns that I am
interested in here, a text column and 3 value columns corresponding to
permissions to certain data classes. I want to put the permission values
in
combo boxes in the grid and instead of displaying the numeric values, have
the combo box display a string that corresponds to the numeric value (i.e.
No Access for 0, Read for 1, Create for 3, and Edit for 7). I have
written
the code below to try to implement this, but it throws an error on
rendering. The error is:
An unhandled exception of type 'System.InvalidCastException'
occurred in system.windows.forms.dll
Additional information: Specified cast is not valid.
I suspect, but can't be sure, that the cast error has to do with the
binding
of the dataset to the pulldown. The column names that I am trying to bind
to are "TSL", "HCT", and "MCT"
Can anyone tell me what I am doing wrong here?
TIA,
Ron L
The code:
' Setup the permissions grid
' Setup the list of Display/Value pairs for the combo
boxes
Dim permsList As DataTable
permsList = New DataTable
permsList.Columns.Add(New DataColumn("Display", GetType(String)))
permsList.Columns.Add(New DataColumn("Id", GetType(Integer)))
permsList.Rows.Add(permsList.NewRow())
permsList.Rows.Add(permsList.NewRow())
permsList.Rows.Add(permsList.NewRow())
permsList.Rows.Add(permsList.NewRow())
permsList.Rows(0)(0) = "No Access"
permsList.Rows(0)(1) = 0
permsList.Rows(1)(0) = "Read"
permsList.Rows(1)(1) = 1
permsList.Rows(2)(0) = "Create"
permsList.Rows(2)(1) = 3
permsList.Rows(3)(0) = "Edit"
permsList.Rows(3)(1) = 7
' Fill the DataTable from the user data dataset (includes user
permissions)
Dim dt As DataTable = dsUserData.Tables(0)
Dim tableStyle As New DataGridTableStyle
tableStyle.GridColumnStyles.Clear()
tableStyle.MappingName = "Table"
tableStyle.MappingName = dt.TableName.ToString
' Setup the Subsystems column
Dim TextCol As New DataGridTextBoxColumn
TextCol.MappingName = dt.Columns(15).ColumnName
TextCol.HeaderText = dt.Columns(15).ColumnName
tableStyle.GridColumnStyles.Add(TextCol)
' Setup the permissions columns
Dim i As Integer
For i = 2 To 4
'Dim textcol2 As New DataGridTextBoxColumn
'textcol2.MappingName = dt.Columns(i).ColumnName
'textcol2.HeaderText = dt.Columns(i).ColumnName
'tableStyle.GridColumnStyles.Add(textcol2)
Dim ComboTextCol As New DataGridComboBoxColumn
ComboTextCol.MappingName = dt.Columns(i).ColumnName
ComboTextCol.HeaderText = dt.Columns(i).ColumnName
ComboTextCol.Width = 120
ComboTextCol.ColumnComboBox.Items.Clear()
ComboTextCol.ColumnComboBox.DataSource = permsList
ComboTextCol.ColumnComboBox.DisplayMember = "Display"
ComboTextCol.ColumnComboBox.ValueMember =
dt.Columns(i).ColumnName
' for the above line I have also tried setting it equal to "Id"
tableStyle.PreferredRowHeight =
ComboTextCol.ColumnComboBox.Height + 2
tableStyle.GridColumnStyles.Add(ComboTextCol)
Next
grdPermissions.TableStyles.Clear()
grdPermissions.TableStyles.Add(tableStyle)
grdPermissions.DataSource = dt
Dim grdStyle As DataGridTableStyle
'no adding of new rows thru dataview...
Dim cm As CurrencyManager
cm = CType(Me.BindingContext(grdPermissions.DataSource,
grdPermissions.DataMember), CurrencyManager)
CType(cm.List, DataView).AllowNew = False
