Save panel as picture in Winfrom

private void Button1_Click (object sender, EventArgs e)
{
Point scrollmaxinfo = Getscrollpoint (Panel1);
Size controlmaxsize = getcontrolsize (Panel1, scrollmaxinfo);

Bitmap controlimage = new Bitmap (controlmaxsize.width, controlmaxsize.height);
Graphics maingraphics = Graphics.fromimage (controlimage);
Bitmap tempimage = new Bitmap (Panel1. Width-16, Panel1. HEIGHT-16);

int stepwidth = Getscrollnumb (Panel1. Width-16, scrollmaxinfo.x);
int stepheight = Getscrollnumb (Panel1. Height-16, SCROLLMAXINFO.Y);

int logwidth = 0;
int logheigh = 0;
Movebar (0, 0, Panel1);

for (int i = 0; I! = Stepwidth; i++)
{
Movebar (1, 0, Panel1);
Logheigh = 0;
for (int z = 0; Z! = stepheight; z++)
{
Panel1. DrawToBitmap (Tempimage, New Rectangle (0, 0, Panel1. Width-16, Panel1. HEIGHT-16));
Maingraphics.drawimage (Tempimage, Logwidth, Logheigh);
Movebar (1, Panel1. Height-16 + Logheigh, panel1);
Logheigh = Getscrollpoint (1, Panel1);
}
Movebar (0, Panel1. Width-16 + logwidth, panel1);
Logwidth = Getscrollpoint (0, Panel1);
}
Maingraphics.dispose ();
Tempimage.dispose ();
Controlimage.save (System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase + "123.png");
}

#region API
[StructLayout (layoutkind.sequential, CharSet = CharSet.Auto)]
public struct SCROLLINFO
{
public UINT cbsize;
public UINT Fmask;
public int nMin;
public int nMax;
public UINT Npage;
public int nPos;
public int ntrackpos;
}
public enum Scrollbarinfoflags
{
Sif_range = 0x0001,
Sif_page = 0x0002,
Sif_pos = 0x0004,
Sif_disablenoscroll = 0x0008,
Sif_trackpos = 0x0010,
Sif_all = (Sif_range | Sif_page | Sif_pos | Sif_trackpos)
}
public enum Scrollbarrequests
{
Sb_lineup = 0,
Sb_lineleft = 0,
Sb_linedown = 1,
Sb_lineright = 1,
Sb_pageup = 2,
Sb_pageleft = 2,
Sb_pagedown = 3,
Sb_pageright = 3,
Sb_thumbposition = 4,
Sb_thumbtrack = 5,
Sb_top = 6,
Sb_left = 6,
Sb_bottom = 7,
Sb_right = 7,
Sb_endscroll = 8
}
[DllImport ("user32.dll", CharSet = CharSet.Auto)]
public static extern int Getscrollinfo (INTPTR hwnd, int bar, ref SCROLLINFO SI);
[DllImport ("user32")]
public static extern int SetScrollPos (IntPtr hWnd, int nBar, int nPos, bool Rush);
[DllImport ("user32.dll", CharSet = CharSet.Auto)]
public static extern int SendMessage (IntPtr hWnd, int msg, int wParam, int lParam);
#endregion

<summary>
Get current scroll bar position
</summary>
<param name= "Bar" ></param>
<param name= "MyControl" ></param>
<returns></returns>
public static int Getscrollpoint (int Bar, Control mycontrol)
{
SCROLLINFO SCROLLINFO = new SCROLLINFO ();
Scrollinfo.cbsize = (UINT) System.Runtime.InteropServices.Marshal.SizeOf (ScrollInfo);
Scrollinfo.fmask = (UINT) Scrollbarinfoflags.sif_all;

Getscrollinfo (Mycontrol.handle, Bar, ref ScrollInfo);

return scrollinfo.npos;
}
<summary>
Get the loop several times to get the graph
</summary>
<returns></returns>
private static int Getscrollnumb (int mycontrolnumb, int scrollmaxinfonumb)
{
Double Step = (double) scrollmaxinfonumb/(double) mycontrolnumb;
step++;

if ((int) Step = = Step)
{
return (int) Step;
}
Else
{
return (int) Step + 1;
}
}
<summary>
Get control does not need scroll bar width and height (final graphics size)
</summary>
<param name= "MyControl" ></param>
<param name= "Scrollmaxinfo" ></param>
<returns></returns>
private static Size Getcontrolsize (Control mycontrol, point Scrollmaxinfo)
{
return new Size (MyControl.Size.Width + scrollmaxinfo.x-16, MyControl.Size.Height + scrollmaxinfo.y-16);
}
<summary>
Get scroll bar data
</summary>
<param name= "MyControl" ></param>
<param name= "Scrollsize" ></param>
<returns></returns>
private static Point Getscrollpoint (Control mycontrol)
{
Point maxscroll = new Point ();

SCROLLINFO SCROLLINFO = new SCROLLINFO ();
Scrollinfo.cbsize = (UINT) System.Runtime.InteropServices.Marshal.SizeOf (ScrollInfo);
Scrollinfo.fmask = (UINT) Scrollbarinfoflags.sif_all;

Getscrollinfo (Mycontrol.handle, 1, ref ScrollInfo);
MAXSCROLL.Y = Scrollinfo.nmax-(int) scrollinfo.npage;
if ((int) Scrollinfo.npage = = 0) maxscroll.y = 0;
Getscrollinfo (mycontrol.handle, 0, ref ScrollInfo);
maxscroll.x = Scrollinfo.nmax-(int) scrollinfo.npage;
if ((int) Scrollinfo.npage = = 0) maxscroll.x = 0;
return maxscroll;
}
<summary>
Move control scroll bar position
</summary>
<param name= "Bar" ></param>
<param name= "Point" ></param>
<param name= "MyControl" ></param>
private static void Movebar (int Bar, int point, Control mycontrol)
{
if (Bar = = 0)
{
SetScrollPos (mycontrol.handle, 0, point, true);
SendMessage (Mycontrol.handle, (int) 0x0114, (int) scrollbarrequests.sb_thumbposition, 0);
}
Else
{
SetScrollPos (Mycontrol.handle, 1, point, true);
SendMessage (Mycontrol.handle, (int) 0x0115, (int) scrollbarrequests.sb_thumbposition, 0);
}
}

Save panel as picture in Winfrom