"fiaolle" <fiao***@telia.com> schreef in bericht
news:ZbOtg.9057$E02.2865@newsb.telia.net...
> Hi
> The first set of source code is the class for a combobox in a grid,
> hopefully. In the second set of code we try to use the combobox class, but
> the grid is empty.
> I don't understand how this works. The first set of code I downloaded from
> internet and when i tried it, it worked fine. But when I changed the
> second
> part of the code it started to give me trouble. Before I changed the code
> they used Datacolumns,Datarows and Datatables and added them to the
> Dataset
> which they used to the Datagrid and it worked fine. I don't understand
> what
> is wrong know that I'm using a table I haven't "made" myself but a table I
> got from a connection. As the third set of code showing, when using
> comboboxes you can set the Datasource to a table you have connected to
> with
> a connection and it works fine, so I think the second part of code should
> work, but the grid is empty when the program starts.
>
> If there is anyone who understand my problem and have a solution, please
> give me an answer.
>
> Thanks
>
> Fia
>
>
> 'The MyComboColumn class
> Imports System.Data
> Imports System.Drawing
> Imports System.Collections
> Imports System.Windows.Forms
> Namespace ComboBoxTest
> Public Class MyComboColumn
> Inherits System.Windows.Forms.DataGridTextBoxColumn
> Private _cboColumn As ComboBox
> Private _objSource As Object
> Private _strMember As String
> Private _strValue As String
> Private _bIsComboBound As Boolean = False
> Private _backBrush As Brush = Nothing
> Private _foreBrush As Brush = Nothing
> Private _iRowNum As Integer
> Private _cmSource As CurrencyManager
> Public Sub New(ByVal objSource As DataSet, ByVal strMember As String,
> ByVal
> strValue As String, ByVal bUseDropDownList As Boolean)
> '_objSource = objSource
> _strMember = strMember
> _strValue = strValue
> _cboColumn = New ComboBox
> _cboColumn.DataSource = objSource.Tables(0)
> _cboColumn.DisplayMember = _strMember
> _cboColumn.ValueMember = _strValue
> If bUseDropDownList = True Then
> _cboColumn.DropDownStyle = ComboBoxStyle.DropDownList
> Me.ReadOnly = True
> Else
> 'AddHandler _cboColumn.KeyPress, AddressOf _cboColumn_KeyPress
> AddHandler _cboColumn.KeyUp, AddressOf _cboColumn_KeyUp
> End If
> AddHandler _cboColumn.Leave, AddressOf cboColumn_Leave
> _cboColumn.Visible = False
> End Sub
> Private Sub _cboColumn_KeyPress(ByVal sender As Object, ByVal e As
> KeyPressEventArgs)
> e.Handled = True
> End Sub
> Private Shadows Sub _cboColumn_KeyUp(ByVal sender As Object, _
> ByVal e As System.Windows.Forms.KeyEventArgs)
> Dim index As Integer
> Dim actual As String
> Dim found As String
> ' Do nothing for certain keys such as navigation keys
> If ((e.KeyCode = Keys.Back) Or _
> (e.KeyCode = Keys.Left) Or _
> (e.KeyCode = Keys.Right) Or _
> (e.KeyCode = Keys.Up) Or _
> (e.KeyCode = Keys.Delete) Or _
> (e.KeyCode = Keys.Down) Or _
> (e.KeyCode = Keys.PageUp) Or _
> (e.KeyCode = Keys.PageDown) Or _
> (e.KeyCode = Keys.Home) Or _
> (e.KeyCode = Keys.ShiftKey) Or _
> (e.KeyCode = Keys.End)) Then
> Return
> End If
> ' Store the actual text that has been typed
> actual = _cboColumn.Text
> ' Find the first match for the typed value
> index = _cboColumn.FindString(actual)
> ' Get the text of the first match
> If (index > -1) Then
> found = _cboColumn.Items(index).ToString()
> ' Select this item from the list
> _cboColumn.SelectedIndex = index
> ' Select the portion of the text that was automatically
> ' added so further typing will replace it
> _cboColumn.SelectionStart = actual.Length
> _cboColumn.SelectionLength = found.Length
> End If
> End Sub
> 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)
> If _bIsComboBound = False Then
> _bIsComboBound = True
> Me.DataGridTableStyle.DataGrid.Controls.Add(_cboColumn)
> End If
> _iRowNum = rowNum
> _cmSource = source
> _cboColumn.Font = Me.TextBox.Font
> Dim anObj As Object = Me.GetColumnValueAtRow(source, rowNum)
> _cboColumn.Bounds = bounds
> _cboColumn.BeginUpdate()
> _cboColumn.Visible = True
> If Not (anObj.GetType Is System.DBNull.Value) Then
> 'TextObject Is System.DBNull.Value
> _cboColumn.SelectedValue = anObj
> Else
> _cboColumn.SelectedIndex = 0
> End If
> _cboColumn.EndUpdate()
> _cboColumn.Focus()
> End Sub
> Public Sub cboColumn_Leave(ByVal sender As Object, ByVal e As EventArgs)
> Dim objValue As Object = _cboColumn.SelectedValue
> If objValue Is Nothing Then
> objValue = DBNull.Value
> Else
> Me.SetColumnValueAtRow(_cmSource, _iRowNum, objValue)
> End If
> _cboColumn.Visible = False
> 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 strCountry As String = "Huh?"
> Dim aRowA As DataRow()
> Dim anObj As Object = Me.GetColumnValueAtRow(source, rowNum)
> Dim aType As Type = anObj.GetType
> If Not (aType.GetType Is System.DBNull.Value) Then
> aRowA = CType(_objSource, DataTable).Select(_strValue + " = " +
> anObj.ToString)
> Else
> aRowA = CType(_objSource, DataTable).Select
> End If
> If aRowA.Length > 0 Then
> strCountry = aRowA(0)(_strMember).ToString
> End If
> Dim rect As Rectangle = bounds
> Dim rectF As RectangleF = rectF.op_Implicit(rect) ' Convert to
> If Me._backBrush Is Nothing Then
> g.FillRectangle(backBrush, rect)
> Else
> g.FillRectangle(_backBrush, rect)
> End If
> rect.Y += 2
> If Me._foreBrush Is Nothing Then
> 'g.DrawString(Text, Me.DataGridTableStyle.DataGrid.Font, ForeBrush, RectF,
> Format)
> g.DrawString(strCountry, Me.TextBox.Font, foreBrush, rectF)
> Else
> g.DrawString(strCountry, Me.TextBox.Font, _foreBrush, rectF)
> End If
> End Sub
> Public WriteOnly Property backgroundColour() As System.Drawing.Color
> Set(ByVal Value As System.Drawing.Color)
> If Value.Equals(System.Drawing.Color.Transparent) Then
> Me._backBrush = Nothing
> Else
> Me._backBrush = New SolidBrush(Value)
> End If
> End Set
> End Property
> Public WriteOnly Property foregroundColour() As System.Drawing.Color
> Set(ByVal Value As System.Drawing.Color)
> If Value.Equals(System.Drawing.Color.Transparent) Then
> Me._foreBrush = Nothing
> Else
> Me._foreBrush = New SolidBrush(Value)
> End If
> End Set
> End Property
> End Class
> End Namespace
>
> ----------------------------------------------------------------------------
> ----------------------------------------------------------------------------
> ------------------------------------
> 'The Form's class
> Imports System
> Imports System.Data
> Imports System.Data.SqlClient
> Imports System.Drawing
> Imports System.ComponentModel
> Imports System.Windows.Forms
> Imports ReceptNet.ComboBoxTest
> Public Class DataGridSample
> Inherits Form
> Private ds As DataSet
> Private myGrid As DataGrid
> Shared Sub Main()
> Application.Run(New DataGridSample)
> End Sub
>
> Private Sub ConnectToData()
> Dim AppPath As String = Replace(Replace(Application.ExecutablePath,
> Application.ProductName + ".exe", ""), Application.ProductName + ".exe",
> "")
> & "Recept.mdb"
> Dim cString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &
> AppPath
> Dim cn As System.Data.OleDb.OleDbConnection = New
> System.Data.OleDb.OleDbConnection(cString)
> Dim adpTables As System.Data.OleDb.OleDbDataAdapter = New
> System.Data.OleDb.OleDbDataAdapter
> adpTables.TableMappings.Add("Table", "Kött")
> cn.Open()
> Dim cmdTable As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM
> Kryddor", cn)
> cmdTable.CommandType = CommandType.Text
> adpTables.SelectCommand = cmdTable
> ds = New DataSet("Customers")
> adpTables.Fill(ds)
> cn.Close()
> Dim GridTableStyle As DataGridTableStyle = New DataGridTableStyle
> GridTableStyle.MappingName = "Kött"
> Me.myGrid.TableStyles.Add(GridTableStyle)
> AddStyle(myGrid,ds)
> End Sub
> Private Sub AddStyle(ByVal grdSrc As DataGrid, ByVal dataS As DataSet)
> Dim aCboCol As MyComboColumn = New MyComboColumn(dataS, "KöttID", "",
> False)
> aCboCol.Width = 129
> aCboCol.MappingName = "KöttID"
> aCboCol.HeaderText = "Kött"
> myGrid.TableStyles("Kött").GridColumnStyles.Add(aCboCol)
> End Sub
> Private Sub DataGridSample_Load(ByVal sender As Object, ByVal e As
> System.EventArgs) Handles MyBase.Load
> ConnectToData()
> End Sub
> End Class
>
>----------------------------------------------------------------------------
> ----------------------------------------------------------------------------
> ------------------------------------
>
> Me.cboDatum.DataSource = ds.Tables(1)
> cboDatum.DisplayMember = "KöttID"
> cboDatum.ValueMember = ""
>
>