------------------ X-class code X ---------------------
Option Strict on
Option Explicit on
Imports system.collections
Imports system.componentmodel
Imports system.drawing
Imports System.Windows.Forms
Imports system.data
Public Class DataGridComboBox
'Similarly to the DataGridTextBox class, define a ComboBox used in the drop-down box class.
Inherits ComboBox
Public Sub New ()
Mybase.new ()
End Sub
Public isineditornaVigateMode as boolean = true
END CLASS
Public Class DataGridComboBOXCOLUMN
Inherits DataGridColumnStyle
'Related variables related to user interface
Private xmargin as integer = 2
Private ymargin as integer = 1
Private Combo As DataGridComboBox
Private _displaymember as string
Private _valuemember as string
'Variables used to track editing state changes
Private OldVal as string = string.empty
Private INEDIT AS BOOLEAN = FALSE
'Constructor - the displaymember of the instance, the valueMEMber value is the value of the Integer type from the parent class.
Public Sub New (Byref Datasource As DataTable, _
Byval Displaymember as integer, _
BYVAL VALUEMEMBER AS INTEGER)
Combo = new dataGridcombox ()
_Displaymember = datasource.columns.Item (index: = displaymember) .tostring
_Valuemember = DataSource.columns.Item (index: = valuemember) .tostring
With Combo
.Visible = false
.Datasource = DataSource
.Displaymember = _displaymember
.Valuemember = _Valuemember
End with
End Sub
'Constructor - DisplayMember, valuemember is the value of string type
Public Sub New (Byref Datasource As DataTable, _
Byval Displaymember As String, _
Byval valuemember as string)
Combo = new dataGridcombox ()
With Combo
.Visible = false
.Datasource = DataSource
.Displaymember = Displaymember
.Valuemember = valuemember
End with
End Sub
'------------------------------------- -----
Method in inheriting from the DataGridColumnStyle class' --------------------------------------- -------------
'Change of the focus leaves the change after ComboBox
Protected Overloads Overrides Sub Abort (BYVAL ROWNUM AS INTEGER)
Debug.writeline ("Abort ()")
Rollback ()
HidecomboBOX ()
Endedit ()
End Sub
'Accept changes
Protected Overloads Overrides Function Commit (Byval DataSource As CurrencyManager, _
BYVAL ROWNUM AS INTEGER AS BOOLEAN
HidecomboBOX ()
IF not inendit
Return True
END IF
Try
DIM Value as object = como.selectedValue
If NullText.equals (Value) THEN
Value = convert.dbnull
END IF
SetColumnValueatrow (Datasource, Rownum, Value)
Catch e as exception
Rollback ()
Return False
END TRY
Endedit ()
Return True
END FUNCTION
'Remove the focus
Protected overloads overrides sub concedefocus ()
Combo.visible = false
End Sub
'Edit cell
Protected Overloads Overrides Sub Edit (Byval Source As CurrencyManager, _
Byval rownum as integer, _
Byval Bounds as Rectangle, _
BYVAL [Readonly] as boolean, _
Byval InstantText As String, _
BYVAL CELLISVISible as boolean)
Combo.Text = String.empty
Dim OriginalBounds as Rectangle = Bounds
Oldval = Combo.Text
IF Cellisvisible Then
Bounds.offset (xmargin, ymargin)
Bounds.width - = xmargin * 2
Bounds.height - = ymargin
Combo.Bounds = Bounds
Combo.visible = true
Else
Combo.Bounds = OriginalBounds
Combo.visible = false
END IF
Combo.selectedValue = GetText (GetColumnValueatrow (Source, Rownum))
IF not instanttext is nothing then
Combo.selectedValue = InstantText
END IF
Combo.righttoleft = me.datagridtablestyle.DataGrid.rightToleft
Combo.focus ()
IF instanttext is nothing thein
Combo.selectall ()
Else
DIM [end] as integer = como.text.lengthcombo.Select ([end], 0)
END IF
IF combo.visible kil
DataGridtablestyle.DataGrid.invalidate (OriginalBounds)
END IF
INEDIT = TRUE
End Sub
Protected overloads overrides function getminimumheight () AS integer
'Set the minimum height of ComboBox
Return Combo.PreferredHeight Ymargin
END FUNCTION
Protected Overloads Overrides Function GetPreferredheight (Byval g as graphics, _
BYVAL VALUE As Object) AS INTEGER
Debug.writeline ("getPreferredHeight ()")
DIM newlineindex as integer = 0
DIM newlines as integer = 0
Dim valueString as string = me.gettext (value)
DO
While NewLineIndex <> -1
NewLineIndex = Valuestring.indexof ("R / N", NewLineIndex 1)
NewLines = 1
End while
Loop
Return Fontheight * NewLines Ymargin
END FUNCTION
Protected Overloads Overrides Function GetPreferredSize (Byvalg as graphics, _
BYVAL VALUE As Object) As size
DIM EXTENTS as size = size.ceiling (g.measureString (gettext (value), _
Me.DataGridtableStyle.DataGrid.font)))
Extents.width = xmargin * 2 DataGridTableGridLineWidth
Extents.height = ymargin
Return Extents
END FUNCTION
Protected Overloads Overrides Sub Paint (Byvalg As Graphics, _
Byval Bounds as Rectangle, _
Byval Source as currencymanager, _
BYVAL ROWNUM AS INTEGER
Paint (G, Bounds, Source, Rownum, False)
End Sub
Protected Overloads Overrides Sub Paint (Byvalg As Graphics, _
Byval Bounds as Rectangle, _
Byval Source as currencymanager, _
Byval rownum as integer, _
Byval aligntoright as boolean)
DIM text as string = getText (getColumnValueatrow (Source, Rownum))
PaintText (G, Bounds, Text, Aligntoright)
End Sub
Protected Overloads Sub Paint (Byvalg 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 text as string = getText (getColumnValueatrow (Source, Rownum))
PaintText (G, Bounds, Text, Backbrush, Forebrush, Aligntoright)
End Sub
Protected Overloads overrides sub setDataGridincolumn (Byval Value As DataGrid)
Mybase.setdataGridincolumn (Value)
IF not (combo.parent is value).
If not (como.parent is nothing ") THEN
Combo.Parent.Controls.Remove (Combo)
END IF
END IF
IF not (value is nothing) Then value.controls.add (Combo)
End Sub
Protected overloads overrides sub Updateui (Byval Source As CurrencyManager, _
Val rownum as integer, byval instanttext as string
Combo.Text = GetText (GetColumnValueatrow (Source, Rownum))
IF not (InstantText is nothing "
Combo.text = instanttext
END IF
End Sub
--- Und finished, see (3) Use the code one ---------
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