public class XDField : XField

Public Class XDField
	Inherits XField

Imports System
Imports BioloMICS.BioCallback
Imports BioloMICS.SharedClasses

Public Class Program

    <STAThread()>
    Shared Sub Main()

        Dim program As New Program
        program.ChangeField()
    End Sub

    '    Write sub functions here
    Public Sub ChangeField()
        '    get the current connection
        Dim SqlCo As XConnection = Run.GetCurrentConnection()
        If SqlCo Is Nothing Then
            Return
        End If

        '    get a table from its User name
        Dim TableDef As XTableDef = SqlCo.GetTableDefByUserNameEng("Your_Table_Name")
        If TableDef Is Nothing Then   '    may happen if that table doesn't exist
            Return
        End If
        '    load a D-Field from that table
        Dim FieldDefMap As New XFieldDefMap
        Dim FieldDef As XFieldDef = SqlCo.GetFieldByUserNameEng("Your_D_Field_name", TableDef.Key)
        If FieldDef Is Nothing Then   '    that field doesn't exist
            Return
        End If
        FieldDefMap.Add(FieldDef)

        '    load all records
        Dim Where As XWhere = XWhere.All

        Dim RecordMap As XRecordMap = Run.LoadRecords(TableDef.Key, FieldDefMap, Where)
        If RecordMap.Count() = 0 Then
            Return   '    no record loaded: nothing else to do
        End If
        For Each Record As XRecord In RecordMap
            Dim Field As XDField = TryCast(Record.Fields(FieldDef.Key), XDField)
            If Field Is Nothing Then   '    this field doesn't exist or is not a D-Field
                Continue For
            End If
            '    *****    D Field    meaning *****
            '    possible values        in Memory        UserInterface
            '    - a real value:    1.25            1.25
            '    - Not a Number:    Double.NaN        "?"

            '    change the field value: replace NaN by 0.0
            If Double.IsNaN(Field.Value) Then      '    NaN
                Field.Value = 0.0             '    = 0.0
            End If

            Record.Save(False)
        Next
    End Sub
End Class