主题：如何解决TextBox复制输入时很慢的问题

mark TextBox慢

你在keydown事件处理一下就好了

If e.Control = True AndAlso e.KeyCode = keys.V Then
    Dim txt As WinForm.TextBox = e.sender
    Dim pstr As String = txt.text.SubString(0, txt.SelectionStart)
    Dim lstr As String = txt.text.SubString(txt.SelectionStart)
    txt.text = pstr & ClipBoard.GetText & lstr
    txt.SelectionStart = pstr.Length + ClipBoard.GetText.length
    e.cancel = True
End If