Visual Basic

'When the following button Click,the Report will showout.
 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim objRpt As New FrmCrystalRpt
        objRpt.strRptName = New CachedCrystalReport1
        
        objRpt.Show()

    End Sub

'The below is my ReportViewer WinForm
Public Class FrmCrystalRpt
    Public strRptName As Object
    Public strRptFilter As String

    Private Sub FrmCrystalRpt_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If strRptFilter <> "" Then
            crptVW.SelectionFormula = strRptFilter
        End If
        crptVW.ReportSource = strRptName
        crptVW.Show()

    End Sub
End Class

Dim SQL4 As String
        selectmonth = ComboBox2.SelectedItem

        SQL4 = "SELECT * FROM lorry_commission WHERE Lorry_No='" & ComboBox1.SelectedItem & "' AND MONTH(Date)='" & selectmonth & "';"
       
        Try
            ObjMyConn.Open()
            ObjAdapter = New MySqlDataAdapter(SQL, ObjMyConn)
            ObjAdapter.Fill(ds, "Salary44")
        Catch ex As Exception
            MsgBox("Error: " & ex.Source & ": " & ex.Message, MsgBoxStyle.OkOnly)
        Finally
            ObjMyConn.Close()
        End Try

Private Sub DGV1_CellFormatting(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles DGV1.CellFormatting
Try
	If e.RowIndex >= -1 And e.RowIndex <= DGV1.RowCount Then 'Basic index validation
		If Not ((DGV1 Is Nothing) OrElse (DGV1.Rows(e.RowIndex) Is Nothing) OrElse (DGV1.Rows(e.RowIndex).DataBoundItem Is Nothing)) Then


			Dim dgvRowState As DataRowState = DirectCast(DGV1.Rows(e.RowIndex).DataBoundItem, DataRowView).Row.RowState
			
			'The idea here is to check that it is only for Non Added/Detatched rows where the Effective From Date is smaller than today
			If Not (dgvRowState = DataRowState.Added OrElse dgvRowState = DataRowState.Detached) _
			   AndAlso e.ColumnIndex = EffectFromDataGridViewTextBoxColumn.Index AndAlso CDate(e.Value).Date < Date.Now.Date Then
				e.CellStyle.BackColor = My.Settings.ReadOnlyColor
				DGV1.Rows(e.RowIndex).Cells(e.ColumnIndex).ReadOnly = True
				DGV1.Rows(e.RowIndex).Cells(Field1.Index).ReadOnly = True
				DGV1.Rows(e.RowIndex).Cells(Field2.Index).ReadOnly = True				

				DGV1.Rows(e.RowIndex).Cells(Field1.Index).Style.BackColor = My.Settings.ReadOnlyColor                            
				DGV1.Rows(e.RowIndex).Cells(Field2.Index).Style.BackColor = My.Settings.ReadOnlyColor
				DGV1.Rows(e.RowIndex).Cells(e.ColumnIndex).Style.BackColor = My.Settings.ReadOnlyColor
				
			End If
		End If
	End If
Catch ex As IndexOutOfRangeException
	Exit Sub 'Exception added to aviod the following behaviour... When the user adds a new line enters a value and use the mouse to
	' navigate to another line, the current new row will be cleared and the cellEndEdit event will be fired. inwhich case the DGV contains
	' a blank row that is not dirty. The row  "DGV1.Rows(RowIndex).DataBoundItem" part gives an exception for this row
End Try

Dim internetExplorer As New SHDocVw.InternetExplorerClass()
        Dim webBrowser As SHDocVw.IWebBrowser2 = CType(internetExplorer, SHDocVw.IWebBrowser2)
        'Make the web browser visible
        webBrowser.Visible = False
        'Display empty page so we have something to manipulate.            
        Dim noValue As Object = System.Reflection.Missing.Value
        webBrowser.Navigate("file://" + fileName, noValue, noValue, noValue, noValue)
        While webBrowser.Busy
            Threading.Thread.Sleep(500)
        End While
        'Get access to the webbrowser's document.
        internetExplorer.ExecWB(SHDocVw.OLECMDID.OLECMDID_PRINT, SHDocVw.OLECMDEXECOPT.OLECMDEXECOPT_DONTPROMPTUSER, noValue, noValue)
        'CType(internetExplorer.Document, mshtml.IHTMLDocument2).close()        
        Marshal.ReleaseComObject(internetExplorer)
        Marshal.ReleaseComObject(webBrowser)

Public Class Contact

    Dim _contactID As zyp_ContactID

    Public Sub New()

    End Sub

    Public Property ContactID() As Guid
        Get
            Return _contactID.value
        End Get
        Set(ByVal value As Guid)
            _contactID.value = value
        End Set
    End Property


    Public Class zyp_ContactID

        Protected Friend Sub New()

        End Sub

        Dim _contactID As Guid

        Public Property value() As Guid
            Get
                Return _contactID
            End Get
            Set(ByVal value As Guid)
                _contactID = value
            End Set
        End Property


    End Class

End Class
br mode="hold" />
In my previous work I've always just had public properties and used Refelection to hydrate from the database.  This allowed me to have a Services class that handled all the hydration through a DatabaseHelper class.  There was only one class for each business object that handled hydrating and only one class for the whole program which interfaced to the database.  Switching to a different database or even to XML or Web Services was just a one-class change (at least as far as the application code was concerned).

I've run into some real limitations with Properties and creating subclasses appears to be the solution.

I previously used code from Chris Rock, <a href="http://www.rocksthoughts.com/blog/archive/2008/04/24/creating-a-datarow-to-customer-object-mapper.aspx">http://www.rocksthoughts.com/blog/archive/2008/04/24/creating-a-datarow-to-customer-object-mapper.aspx</a>, to map from a database to a custom business object.  So long as I used the attribute it has worked perfectly.

So now I need help with the following:

For each property in the class

1. Is the property a class ?
2. If so, does the class have a property of "value" ?
3. If so, can we write to the property "value" ?
4. If so, write to the property "value".

Any hints are greatly appreciated...I'm stuck on this and hate the idea of not being able to use a generic mapper class.

As an alternative, is there a way to pass a reference to a function to a sub so that the sub can call the function referenced.  This is a backup option if I can't get the generic mapper class to work.