Custom DataGRidComboBoxStyle DataSource Problems

**Ken Tucker [MVP]** · Mar 1 '06, 11:05 PM

Re: Custom DataGRidComboBo xStyle DataSource Problems

Hi,

http://www.vb-tips.com/default.aspx?ID=e51432cb-e517-4bae-bc26-7320e41e6d05

Ken
------------------
"Richard Ryerson" <rjryerson@xyzn eo.rr.com> wrote in message
news:PhnNf.1126 23$tK4.42444@to rnado.ohiordc.r r.com...[color=blue]
>I have a general DataGridComboBo xColumn that I built using the Example in
> the .NET 2003 Combined Collection help file (that was a data time picker).
>
> I am able to assign a data source and display / value members so the
> ComboBox is data bound and that works, to a point. What generally works is
> the ComboBox get's populated and the ComboBox shows itself when the
> appropriate column/row is selected. When the ComboBoxColumn isn't selected
> it displays the correct text value (not the related key id value). Alls
> cool, until I bind with a DataSet that contains multiple tables related
> with
> DataRelations.
>
> If there are multiple rows, The last row selected properly displays it's
> combobox values / or data values. The other rows display blanks. (I set
> the
> comboboxcolumn to display blanks when it can't find the correct value in
> the
> dataset/table/relation.)
>
>
> I believe this is because of the DataRelation. There is relational data
> between on column and another, I.e. a customer ship to location applies to
> a
> single customer. When the last selected row is customer Ford, then the
> Chrysler records display blanks in the customer ship to .
>
> Because of the DataRelation it is limiting the data that each combo box is
> privy to. And every combo box (shipto's) shares the data source, I
> believe.
>
> Anyone have any good ideas on how to 'fix' this anomoly? Any help is
> greatly
> appreciated.
>
> Best Regards,
>
> Rick
>
>[/color]

**Richard Ryerson** · Mar 2 '06, 03:55 AM

Re: Custom DataGRidComboBo xStyle DataSource Problems

Yeah, I am able to display the "words" but state is being lost when selected
"row" changes in the datagrid, due to the relation performing it's job. I
need a viable way to save previous states and call upon that.

"Ken Tucker [MVP]" <vb2ae@bellsout h.net> wrote in message
news:eOoB2IYPGH A.3856@TK2MSFTN GP12.phx.gbl...[color=blue]
> Hi,
>
>[/color]
http://www.vb-tips.com/default.aspx?...6-7320e41e6d05[color=blue]
>
> Ken
> ------------------
> "Richard Ryerson" <rjryerson@xyzn eo.rr.com> wrote in message
> news:PhnNf.1126 23$tK4.42444@to rnado.ohiordc.r r.com...[color=green]
> >I have a general DataGridComboBo xColumn that I built using the Example in
> > the .NET 2003 Combined Collection help file (that was a data time[/color][/color]
picker).[color=blue][color=green]
> >
> > I am able to assign a data source and display / value members so the
> > ComboBox is data bound and that works, to a point. What generally works[/color][/color]
is[color=blue][color=green]
> > the ComboBox get's populated and the ComboBox shows itself when the
> > appropriate column/row is selected. When the ComboBoxColumn isn't[/color][/color]
selected[color=blue][color=green]
> > it displays the correct text value (not the related key id value). Alls
> > cool, until I bind with a DataSet that contains multiple tables related
> > with
> > DataRelations.
> >
> > If there are multiple rows, The last row selected properly displays it's
> > combobox values / or data values. The other rows display blanks. (I set
> > the
> > comboboxcolumn to display blanks when it can't find the correct value in
> > the
> > dataset/table/relation.)
> >
> >
> > I believe this is because of the DataRelation. There is relational data
> > between on column and another, I.e. a customer ship to location applies[/color][/color]
to[color=blue][color=green]
> > a
> > single customer. When the last selected row is customer Ford, then the
> > Chrysler records display blanks in the customer ship to .
> >
> > Because of the DataRelation it is limiting the data that each combo box[/color][/color]
is[color=blue][color=green]
> > privy to. And every combo box (shipto's) shares the data source, I
> > believe.
> >
> > Anyone have any good ideas on how to 'fix' this anomoly? Any help is
> > greatly
> > appreciated.
> >
> > Best Regards,
> >
> > Rick
> >
> >[/color]
>
>[/color]

**Richard Ryerson** · Mar 2 '06, 04:15 AM

Re: Custom DataGRidComboBo xStyle DataSource Problems

Here is the scenario.

Customers (Id, Name)
-------------
1, Ford
2, Chrysler

ShipTos (Id, CustId, Location)
---------
1, 1, XYZ
2, 1, PDQ
3, 2, FAQ
4, 2, ROF

There is a relation between Customers and ShipTos (Customers.Id ->
ShipTos.CustId)

Now main DataTable (Releases) contains info pertaining to Customers and
ShipTos

Releases (Id, CustId, ShipToId, Qty)
----------
1, 1, 1, 5000 (1, Ford, XYZ, 5000)
2, 2, 4, 2500 (2, Chrysler, ROF, 2500)

When the data grid first displays, it only displays complete information for
the second row, because this is the last row in the grid, and therefore the
last DataRelation view set i'll call it. The First record does not display
correctly because it's data is violating the DataRelation constraints.
(ShipTo XYZ does not relate to Chrysler). So, that column gets displayed as
a blank, because to display the 'word' you must traverse or find the 'word'
by the key (1) in the current view.

It appears that each ComboBox 'shares' it's properties / data whatever
regardless of the row. I need a way to search the correct Relation or
remember (bad code) the previous data relation information. I've tried
storing the data/state in a hashtable, but it seems to not work.

Here is the code for the ComboBoxColumn. It needs to be as extendable /
useful as possible. Meaning I can't design this comboboxstyle to work ONLY
in this situation.

Best regards,

Rick

Imports System.Componen tModel

Public Class DataGridComboBo xColumn

Inherits DataGridColumnS tyle

Private _isEditing As Boolean = False

Private WithEvents _comboBox As ComboBox

Private _dataSource As Object

Private _dataMember As String

Private _valueMember As String

Private _displayMember As String

Private _lists As Hashtable

Protected Sub OnPropertyChang ed(ByVal e As PropertyChanged EventArgs)

Select Case e.PropertyName

Case "DataSource "

_comboBox.DataS ource = _dataSource

Case "ValueMembe r"

If _dataMember Is Nothing Then

_comboBox.Value Member = _valueMember

Else

_comboBox.Value Member = String.Format(" {0}.{1}", _dataMember, _valueMember)

End If

Case "DisplayMem ber"

If _dataMember Is Nothing Then

_comboBox.Displ ayMember = _displayMember

Else

_comboBox.Displ ayMember = String.Format(" {0}.{1}", _dataMember,
_displayMember)

End If

End Select

Invalidate()

End Sub

Public ReadOnly Property DataBindings() As ControlBindings Collection

Get

Return _comboBox.DataB indings

End Get

End Property

Public Property DataSource() As Object

Get

Return _dataSource

End Get

Set(ByVal Value As Object)

_dataSource = Value

OnPropertyChang ed(New PropertyChanged EventArgs("Data Source"))

End Set

End Property

Public Property ValueMember() As String

Get

Return _valueMember

End Get

Set(ByVal Value As String)

_valueMember = Value

OnPropertyChang ed(New PropertyChanged EventArgs("Valu eMember"))

End Set

End Property

Public Property DisplayMember() As String

Get

Return _displayMember

End Get

Set(ByVal Value As String)

_displayMember = Value

OnPropertyChang ed(New PropertyChanged EventArgs("Disp layMember"))

End Set

End Property

Public Property DataMember() As String

Get

Return _dataMember

End Get

Set(ByVal Value As String)

_dataMember = Value

OnPropertyChang ed(New PropertyChanged EventArgs("Data Member"))

End Set

End Property

Public Sub New()

_comboBox = New ComboBox

_lists = New Hashtable

_comboBox.Visib le = False

End Sub

Protected Overrides Sub Abort(ByVal rowNum As Integer)

_isEditing = False

DataGridTableSt yle.DataGrid.In validate(_combo Box.Bounds)

End Sub

Protected Overrides Function Commit(ByVal dataSource As
System.Windows. Forms.CurrencyM anager, ByVal rowNum As Integer) As Boolean

_comboBox.Bound s = Rectangle.Empty

If Not _isEditing Then

Return True

End If

_isEditing = False

Try

Dim value As Object

value = _comboBox.Selec tedValue

If NullText.Equals (value) Then

value = System.Convert. DBNull

End If

SetColumnValueA tRow(dataSource , rowNum, value)

Catch ex As Exception

End Try

DataGridTableSt yle.DataGrid.In validate(_combo Box.Bounds)

Return True

End Function

Protected Overloads Overrides Sub Edit(ByVal source As
System.Windows. Forms.CurrencyM anager, ByVal rowNum As Integer, ByVal bounds
As System.Drawing. Rectangle, ByVal [readOnly] As Boolean, ByVal instantText
As String, ByVal cellIsVisible As Boolean)

Dim value As Object = GetText(GetColu mnValueAtRow(so urce, rowNum))

If cellIsVisible Then

_comboBox.Bound s = New Rectangle(bound s.X + 2, bounds.Y + 2, bounds.Width -
4, bounds.Height - 4)

_comboBox.Visib le = True

Else

_comboBox.Visib le = False

End If

If _comboBox.Visib le Then

DataGridTableSt yle.DataGrid.In validate(bounds )

End If

End Sub

Protected Overrides Function GetMinimumHeigh t() As Integer

Return _comboBox.Prefe rredHeight + 4

End Function

Protected Overrides Function GetPreferredHei ght(ByVal g As
System.Drawing. Graphics, ByVal value As Object) As Integer

Return _comboBox.Prefe rredHeight + 4

End Function

Protected Overrides Function GetPreferredSiz e(ByVal g As
System.Drawing. Graphics, ByVal value As Object) As System.Drawing. Size

Return New Size(_comboBox. Width + 4, _comboBox.Prefe rredHeight + 4)

End Function

Protected Overloads Overrides Sub Paint(ByVal g As System.Drawing. Graphics,
ByVal bounds As System.Drawing. Rectangle, ByVal source As
System.Windows. Forms.CurrencyM anager, ByVal rowNum As Integer)

Paint(g, bounds, [source], rowNum, False)

End Sub

Protected Overloads Overrides Sub Paint(ByVal g As System.Drawing. Graphics,
ByVal bounds As System.Drawing. Rectangle, ByVal source As
System.Windows. Forms.CurrencyM anager, ByVal rowNum As Integer, ByVal
alignToRight As Boolean)

Paint(g, bounds, [source], rowNum, Brushes.Red, Brushes.Blue, alignToRight)

End Sub

Protected Overloads Overrides Sub Paint(ByVal g As Graphics, ByVal bounds As
Rectangle, ByVal [source] As CurrencyManager , ByVal rowNum As Integer, ByVal
backBrush As Brush, ByVal foreBrush As Brush, ByVal alignToRight As Boolean)

Dim value As Object = GetColumnValueA tRow([source], rowNum)

Dim rect As Rectangle = bounds

Dim s As String = Nothing

Dim displayMem As String

Dim valueMem As String

If _lists(rowNum) Is Nothing Then

Dim col(_comboBox.I tems.Count - 1) As Object

_comboBox.Items .CopyTo(col, 0)

_lists.Add(rowN um, col)

End If

'loop through the items of the combo box

'this items collection seems to be shared

'between all the instances of the same

'column of combo boxes.

Dim col2() As Object = _lists(rowNum)

For Each drv As DataRowView In _comboBox.Items

If _valueMember.In dexOf(_dataMemb er) > -1 Then

'remove the Parent.Relation . from the value member

valueMem = _valueMember.Re place(_dataMemb er, "").Remove( 0, 1)

Else

valueMem = _valueMember

End If

If _displayMember. IndexOf(_dataMe mber) > -1 Then

'remove the Parent.Relation . from the display member

displayMem = _displayMember. Replace(_dataMe mber, "").Remove( 0, 1)

Else

displayMem = _displayMember

End If

'make sure it's not a added row

If Not value Is Nothing AndAlso Not value Is System.DBNull.V alue Then

If drv(valueMem) = value Then

Try

s = drv(displayMem)

Catch ex As Exception

s = value

End Try

Exit For

End If

Else

s = Me.NullText

Exit For

End If

Next

g.FillRectangle (backBrush, rect)

rect.Offset(0, 2)

rect.Height -= 2

If Not s Is Nothing Then

If value Is Nothing Then

s = NullText

End If

Try

g.DrawString(s. ToString, Me.DataGridTabl eStyle.DataGrid .Font, foreBrush,
RectangleF.From LTRB(rect.X, rect.Y, rect.Right, rect.Bottom))

Catch ex As Exception

Debug.WriteLine (ex.ToString)

End Try

End If

End Sub

Protected Overrides Sub SetDataGridInCo lumn(ByVal value As DataGrid)

MyBase.SetDataG ridInColumn(val ue)

If Not (_comboBox.Pare nt Is Nothing) Then

_comboBox.Paren t.Controls.Remo ve(_comboBox)

End If

If Not (value Is Nothing) Then

value.Controls. Add(_comboBox)

End If

End Sub

Public Overrides Property Width() As Integer

Get

Return MyBase.Width

End Get

Set(ByVal Value As Integer)

MyBase.Width = Value

_comboBox.Width = Value - 4

End Set

End Property

Private Function GetText(ByVal value As Object) As String

If value Is System.DBNull.V alue Then

Return Me.NullText

Else

If Not value Is Nothing Then

Return value.ToString

Else

Return String.Empty

End If

End If

End Function

Private Sub _comboBox_Selec tedIndexChanged (ByVal sender As Object, ByVal e
As System.EventArg s) Handles _comboBox.Selec tedIndexChanged

_isEditing = True

MyBase.ColumnSt artedEditing(_c omboBox)

End Sub

End Class

Best regards,

Rick

Custom DataGRidComboBoxStyle DataSource Problems

Custom DataGRidComboBoxStyle DataSource Problems

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