C# 用按键控制 TextBox 的滚动条

[DllImport("user32.dll", EntryPoint = "SendMessage")] public static extern int SendMessage( int hwnd, int wMsg, int wParam, int lParam ); const int EM_LINESCROLL = 0xB6; private void textBox_ChpText_KeyDown(object sender, KeyEventArgs e) { if (e.KeyValue == 38) //上 { // textBox_ChpText.ScrollToCaret(); int lParam=-1; SendMessage( (int)textBox_ChpText.Handle, EM_LINESCROLL, 0, lParam); e.Handled = true; } if (e.KeyValue == 40) //下 { int lParam = 1; SendMessage( (int)textBox_ChpText.Handle, EM_LINESCROLL, 0, lParam); e.Handled = true; } }