Implementing the IAutoComplete2 Interface in Vb.Net

[dynamic_sysop]

Ive been teaching myself a bit about Interfaces for a little while and decided to try to create a vb.net version of the IAutoComplete2 interface.
you can see info on this for C++ on msdn.
this example implements autocomplete on an given array of strings ( eg: in a listbox , combobox etc... )

    Private autoComp As AutoComplete

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        /// add autocomlete to an array of strings, in this case a listbox
        autoComp = New AutoComplete(TextBox1.Handle, ArrayList.Adapter(ListBox1.Items))
        /// enable autocomplete
        autoComp.Enable()

    End Sub
End Class

#Region " AutoComplete Class "

Public Class AutoComplete
    Implements IDisposable

    Private autoComp As Type
    Private objAutoComp As IAutoComplete

    Public Sub New(ByVal hwndEdit As IntPtr, ByVal strList As ArrayList, Optional ByVal pwszRegKeyPath As String = Nothing, Optional ByVal pwszQuickComplete As String = Nothing)
        Dim iEnumList As New EnumString()
        iEnumList.strArray = strList

        autoComp = Type.GetTypeFromCLSID(New Guid("{00BB2763-6A77-11D0-A535-00C04FD7D062}"))
        objAutoComp = DirectCast(Activator.CreateInstance(autoComp), IAutoComplete)

        /// initialize IAutoComplete
        objAutoComp.Init(hwndEdit, iEnumList, pwszRegKeyPath, pwszQuickComplete)
        /// set IAutoComplete Options
        objAutoComp.SetOptions(Convert.ToUInt32(ShowOptions.ACO_AUTOSUGGEST Or ShowOptions.ACF_UPDOWNKEYDROPSLIST Or ShowOptions.ACO_AUTOAPPEND))
        /// Enable IAutoComplete
        objAutoComp.Enable(True)

    End Sub

    Public Sub Dispose() Implements System.IDisposable.Dispose
        Me.ReleaseComObject = Marshal.ReleaseComObject(objAutoComp)
    End Sub

    Private WriteOnly Property ReleaseComObject()
        Set(ByVal Value)
            Me.ReleaseComObject = Value
        End Set
    End Property

    Public Sub Disable()
        objAutoComp.SetOptions(Convert.ToUInt32(ShowOptions.ACO_NONE))
    End Sub

    Public Sub Enable()
        objAutoComp.SetOptions(Convert.ToUInt32(ShowOptions.ACO_AUTOSUGGEST Or ShowOptions.ACF_UPDOWNKEYDROPSLIST Or ShowOptions.ACO_AUTOAPPEND))
    End Sub

End Class

#End Region


#Region " IAutoComplete2 Interface "

<ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("EAC04BC0-3791-11D2-BB95-0060977B464C")> _
Public Interface IAutoComplete

    Function Init(ByVal hwndEdit As IntPtr, <MarshalAs(UnmanagedType.IUnknown)> ByVal punkACL As Object, ByVal pwszRegKeyPath As String, ByVal pwszQuickComplete As String) As Int32
    /// we must use <PreserveSig()> _ otherwise after using autocomplete , fields will not return the next time
    <PreserveSig()> _
    Function Enable(<[In]()> ByVal fEnable As Boolean) As Boolean
    <PreserveSig()> _
    Function SetOptions(<[In]()> ByVal dwFlag As UInt32) As Integer
    <PreserveSig()> _
    Function GetOptions(<Out()> ByRef pdwFlag As UInt32) As Integer

End Interface

#End Region

#Region " IEnumString Interface "
/// HKEY_CLASSES_ROOT\Interface\{00000101-0000-0000-C000-000000000046}\IEnumString
<ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00000101-0000-0000-C000-000000000046")> _
Public Interface IEnumString

    Function [Next](ByVal celt As Integer, ByVal rgelt() As String, ByRef pceltFetched As Integer) As Integer
    Function Skip(ByVal celt As Integer) As Integer
    Function Reset() As Integer
    Sub Clone(ByRef ppenum As IEnumString)

End Interface

#End Region

#Region " IEnumString Class "

Public Class EnumString
    /// UCOMIEnumString is the same as the IEnumString interface
    /// see more at Msdn on [url]http://msdn.microsoft.com/library/default.asp?url=/library/en-us/com/htm/cmi_d2l_89uv.asp[/url]
    Implements UCOMIEnumString

    Public strArray As ArrayList
    Private Pos As Integer = 0

    Public Function [Next](ByVal celt As Integer, ByVal rgelt As String(), ByRef pceltFetched As Integer) As Integer Implements UCOMIEnumString.Next
        Dim retval As Integer = 1
        pceltFetched = 0
        While Not Pos = strArray.Count AndAlso Not pceltFetched = celt
            rgelt(pceltFetched) = strArray(Pos)
            pceltFetched += 1
            Pos += 1
        End While

        If Not pceltFetched.CompareTo(celt) = -1 Then
            retval = 0
        End If

        Return retval

    End Function

    Public Function Skip(ByVal celt As Integer) As Integer Implements UCOMIEnumString.Skip
        Dim retval As Integer = 1
        Pos += celt

        If Not Pos = strArray.Count Then
            retval = 0
        End If

        Return retval
    End Function

    Public Function Reset() As Integer Implements UCOMIEnumString.Reset
        Pos = 0
        Return Pos
    End Function


    Public Sub Clone(ByRef ppenum As UCOMIEnumString) Implements UCOMIEnumString.Clone
        /// create a Clone of this Class
        ppenum = DirectCast(Me, EnumString)
    End Sub

End Class

#End Region

#Region " AutoComplete Show Options Enums "

Public Enum ShowOptions
    ACO_NONE = 0
    ACO_AUTOSUGGEST = &H1
    ACO_AUTOAPPEND = &H2
    ACO_SEARCH = &H4
    ACO_FILTERPREFIXES = &H8
    ACO_USETAB = &H10
    ACF_UPDOWNKEYDROPSLIST = &H20
    ACO_RTLREADING = &H40
End Enum

#End Region

included as always a sample project...

 

[Derek Stone]

Good stuff!

 

[dynamic_sysop]

thanks for the compliment Derek