DataBindingController.vb

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Windows.Forms

Namespace RichEditCustomInsertMergeFieldMenu

    Public Class DataBindingController

        Private Shared bindingContext As BindingContext = New BindingContext()

        Private dataSource As Object

        Private dataMember As String

        Private bindingManager As BindingManagerBase = Nothing

        Private itemProperties As PropertyDescriptorCollection = Nothing

        Public Sub New(ByVal dataSource As Object, ByVal dataMember As String)
            Me.dataSource = dataSource
            Me.dataMember = dataMember
            InitializeBindingManagerAndItemProperties()
        End Sub

        Private Sub InitializeBindingManagerAndItemProperties()
            If dataSource IsNot Nothing Then
                If dataMember.Length > 0 Then
                    bindingManager = bindingContext(dataSource, dataMember)
                Else
                    bindingManager = bindingContext(dataSource)
                End If
            End If

            If bindingManager IsNot Nothing Then itemProperties = bindingManager.GetItemProperties()
        End Sub

        Public ReadOnly Property ItemsCount As Integer
            Get
                Return If(bindingManager IsNot Nothing, bindingManager.Count, 0)
            End Get
        End Property

        Public ReadOnly Property ColumnNames As List(Of String)
            Get
                Dim list As List(Of String) = New List(Of String)()
                If itemProperties IsNot Nothing Then
                    Dim count As Integer = itemProperties.Count
                    For i As Integer = 0 To count - 1
                        list.Add(itemProperties(i).Name)
                    Next
                End If

                Return list
            End Get
        End Property

        Public Function GetColumnInfo(ByVal columnName As String) As PropertyDescriptor
            If itemProperties IsNot Nothing Then
                Dim prop As PropertyDescriptor = itemProperties.Find(columnName, False)
                If prop Is Nothing Then Throw New ArgumentException(String.Format("'{0}' column does not exist", columnName))
                Return If(itemProperties IsNot Nothing, itemProperties(columnName), Nothing)
            End If

            Return Nothing
        End Function

        Public Function GetRowValue(ByVal columnName As String, ByVal rowIndex As Integer) As Object
            If bindingManager IsNot Nothing AndAlso itemProperties IsNot Nothing Then
                Dim prop As PropertyDescriptor = itemProperties.Find(columnName, False)
                If prop Is Nothing Then Throw New ArgumentException(String.Format("'{0}' column does not exist", columnName))
                If TypeOf bindingManager Is CurrencyManager Then
                    Return prop.GetValue(CType(bindingManager, CurrencyManager).List(rowIndex))
                Else
                    If rowIndex <> 0 Then Throw New ArgumentOutOfRangeException("rowIndex")
                    Return prop.GetValue(CType(bindingManager, PropertyManager).Current)
                End If
            End If

            Return Nothing
        End Function
    End Class
End Namespace