URLのオートコンプリート機能を付ける

''' <summary>
''' オートコンプリート機能を持ったコンボボックス
''' </summary>
Public Class AutoCompleteComboBox

    Inherits System.Windows.Forms.ComboBox

    <DllImport("user32.dll")> _
    Private Shared Function FindWindowEx( _
        ByVal hWndParent As IntPtr, _
        ByVal hwndChildAfter As IntPtr, _
        ByVal lpszClass As String, _
        ByVal lpszWindow As String) _
        As IntPtr
    End Function

    <DllImport("shlwapi.dll")> _
    Private Shared Function SHAutoComplete( _
        ByVal hwndEdit As IntPtr, _
        ByVal dwFlags As SHAutoCompleteFlags) _
        As Integer
    End Function

    <Flags()> _
    Private Enum SHAutoCompleteFlags As Integer

        SHACF_DEFAULT = &H0
        SHACF_FILESYSTEM = &H1
        SHACF_URLALL = SHACF_URLHISTORY Or SHACF_URLMRU
        SHACF_URLHISTORY = &H2
        SHACF_URLMRU = &H4
        SHACF_USETAB = &H8
        SHACF_FILESYS_ONLY = &H10
        SHACF_AUTOSUGGEST_FORCE_ON = &H10000000
        SHACF_AUTOSUGGEST_FORCE_OFF = &H20000000
        SHACF_AUTOAPPEND_FORCE_ON = &H40000000
        SHACF_AUTOAPPEND_FORCE_OFF = &H80000000

    End Enum

    Protected Overrides Sub OnHandleCreated(ByVal e As EventArgs)

        Dim hWndEdit As IntPtr = FindWindowEx(Me.Handle, IntPtr.Zero, "EDIT", Nothing)

        ' オートコンプリートを有効にする
        If Not IntPtr.Zero.Equals(hWndEdit) Then SHAutoComplete(hWndEdit, SHAutoCompleteFlags.SHACF_URLALL)

        MyBase.OnHandleCreated(e)

    End Sub

End Class