Invalid Cast from string with ComboBox in datagrid
Chris
datagrid is a databound combobox. I followed the instructions
according to the following site:
http://www.syncfusion.com/FAQ/WindowsForms/FAQ_c44c.aspx#q480q
When the form loads I get an error message stating: Cast from string
"7.7% Notes due 5/19/2010" to type 'Double' is not valid. The "7.7%
Notes due 5/19/2010" is the first row in my combobox. I cant seem to
find where the code is trying to convert this to double. Pieces of my
code are below:
Here is the code that adds the combobox to my datagrid:
'Combo box section
Dim ComboTextCol As New DataGridComboBoxColumn
ComboTextCol.MappingName = "SecurityType" 'must be from the
grid table...
ComboTextCol.HeaderText = "Security Type"
ComboTextCol.Width = 150
Dim dv As New
DataView(dsSecurityTypesListing.Tables("SecurityTypes"), "",
"SecurityTypeID", DataViewRowState.CurrentRows)
ComboTextCol.ColumnComboBox.DataSource =
dsSecurityTypesListing.Tables("SecurityTypes").DefaultView 'dv;
ComboTextCol.ColumnComboBox.DisplayMember = "SecurityType"
ComboTextCol.ColumnComboBox.ValueMember = "SecurityTypeID"
'tableStyleClassTypeStart.PreferredRowHeight =
ComboTextCol.ColumnComboBox.Height + 1
tableStyleClassTypeStart.GridColumnStyles.Add(ComboTextCol)
Here is the code that creates the DatagridComboBox
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
'NameSpace DataGridTextBoxCombo
' 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
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
'End Namespace