控制文本框的滚动

来源：互联网发布：西安爱知中学招聘编辑：程序博客网时间：2024/05/03 01:04

   [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern bool UpdateWindow(IntPtr hWnd);     //   handle   to   window

        private const int WM_VSCROLL = 0x115;
        private const int SB_LINEUP = 0;
        private const int SB_LINELEFT = 0;
        private const int SB_LINEDOWN = 1;
        private const int SB_LINERIGHT = 1;
        private const int SB_PAGEUP = 2;
        private const int SB_PAGELEFT = 2;
        private const int SB_PAGEDOWN = 3;
        private const int SB_PAGERIGHT = 3;
        private const int SB_THUMBPOSITION = 4;
        private const int SB_THUMBTRACK = 5;
        private const int SB_TOP = 6;
        private const int SB_LEFT = 6;
        private const int SB_BOTTOM = 7;
        private const int SB_RIGHT = 7;
        private const int SB_ENDSCROLL = 8;
        private const int WM_PAINT = 0x000F;

        private void SelfSrcoll(IntPtr handle, int length)
        {
            if (length != 0)
            {
                SendMessage(handle, WM_VSCROLL, SB_LINEUP, 0);
                UpdateWindow(handle);
            }
            else
            {
                SendMessage(handle, WM_VSCROLL, SB_BOTTOM, 0);
                UpdateWindow(handle);
            }
        }

        private void vScrollBar1_Scroll(object sender, ScrollEventArgs e)
        {
            int lines = e.NewValue - e.OldValue;
            if (lines > 0)
            {
                for (int i = 0; i < lines; i++)
                {
                    SendMessage(this.textBox1.Handle, WM_VSCROLL, SB_LINEUP, 0);
                    UpdateWindow(this.textBox1.Handle);
                }
            }
            else
            {
                for (int i = 0; i > lines; i--)
                {
                    SendMessage(this.textBox1.Handle, WM_VSCROLL, SB_LINEDOWN, 0);
                    UpdateWindow(this.textBox1.Handle);
                }
            }

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            vScrollBar1.Maximum = textBox1.Lines.Length;
        }