在窗体中加入一个 Listbox、Combox、Textbox 控件。
在Textbox中逐步输入字符，会快速地选择并定位最接近的项。

Public Class Form1

    Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, <Runtime.InteropServices.MarshalAs(Runtime.InteropServices.UnmanagedType.AsAny)> ByVal lParam As Object) As Int32
    'Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Int32, ByVal wMsg As Message) As Int32
    Const WM_SETTEXT = &HC
    Const CB_ADDSTRING = &H143
    Const LB_FINDSTRING = &H18F
    Const CB_FINDSTRING = &H14C
    Const LB_SETHORIZONTALEXTENT = &H194
    Const CB_SETHORIZONTALEXTENT = &H15E

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ListBox1.Items.Add("a")
        ListBox1.Items.Add("ab")
        ListBox1.Items.Add("ac")
        ListBox1.Items.Add("abd")
        ListBox1.Items.Add("abc")
        ListBox1.Items.Add("bc")
        ListBox1.Items.Add("bs")
        ListBox1.Items.Add("bcd")

        For Each s As String In ListBox1.Items
            ComboBox1.Items.Add(s)
        Next

        SendMessage(ListBox1.Handle, LB_SETHORIZONTALEXTENT, 250, 0)
        SendMessage(ComboBox1.Handle, CB_SETHORIZONTALEXTENT, 250, 0)
    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        ListBox1.SelectedIndex = SendMessage(ListBox1.Handle, LB_FINDSTRING, -1, TextBox1.Text)
        ComboBox1.SelectedIndex = SendMessage(ComboBox1.Handle, CB_FINDSTRING, -1, TextBox1.Text)

    End Sub
End Class