textchanged事件

If e.Sender.text > "" Then
    systemready = False
    Dim idx As Integer = e.Sender.SelectionStart
    Dim fdr As DataRow = DataTables("表A").find("第一列 like \'" & e.sender.Text.SubString(0,idx) & "%\'")
    If fdr IsNot Nothing Then
        e.sender.text = fdr("第一列")
        e.Sender.SelectionStart = idx
        e.Sender.SelectionLength = e.Sender.Text.length-idx
    End If
    systemready = True
End If

keydown事件

If e.KeyCode = keys.delete Then
    Dim idx As Integer = e.sender.SelectionStart
    Dim str = left(e.sender.text, idx)
    str &= right(e.sender.text, e.sender.text.length-idx-e.Sender.SelectionLength)
    Systemready = False
    e.sender.text = str
    e.sender.SelectionStart = idx
    Systemready = True
ElseIf e.KeyCode = Keys.Back Then
    If e.sender.SelectionLength > 0 Then
        Dim idx As Integer = e.sender.SelectionStart
        Dim str = left(e.sender.text, idx-1)
        str &= right(e.sender.text, e.sender.text.length-idx-e.Sender.SelectionLength)
        Systemready = False
        e.sender.text = str
        If e.sender.text > "" Then
            e.sender.SelectionStart = idx
            Dim fdr As DataRow = DataTables("表A").find("第一列 like \'" & e.sender.Text & "%\'")
            If fdr IsNot Nothing Then
                e.sender.text = fdr("第一列")
                e.Sender.SelectionStart = str.length
                e.Sender.SelectionLength = e.Sender.Text.length-str.length
            End If
        End If
        systemready = True
        e.cancel = True
    End If
End If