protected override void WndProc(ref Message msg)
{
if (msg.Msg == Win32.WM_HSCROLL)
{
// Store the handle for use in Invalidate()
_hScrollbarHandle = msg.HWnd;
// Collect info about the position of the horizontal scrollbar
Win32.ScrollInfo si = new Win32.ScrollInfo();
si.fMask = (int)Win32.ScrollInfoMask.SIF_ALL;
si.cbSize = (uint)Marshal.SizeOf(si);
Win32.GetScrollInfo(msg.HWnd, 0, ref si);
if ((msg.WParam.ToInt32() & 0xFF) == Win32.SB_THUMBTRACK)
{
// If the user is in the middle of dragging the scrollbar, we're interested in
// the 'track' position
_scrollLeft = si.nTrackPos;
}
else
{
// Otherwise just the regular scrollbar position
_scrollLeft = si.nPos;
}
// Force repaint
base.Invalidate();
}
if (!CancelWndProc(msg))
{
base.WndProc(ref msg);
}
}
private int ScrollInfo(Win32.ScrollBarConstants fnBar)
{
Win32.ScrollInfo si = new Win32.ScrollInfo();
si.cbSize = (uint)Marshal.SizeOf(si);
si.fMask = (int)Win32.ScrollInfoMask.SIF_POS;
if (!Win32.GetScrollInfo(Handle, (int)fnBar, ref si))
{
return(0);
}
return(si.nPos);
}
protected override void WndProc(ref Message m)
{
int msg = m.Msg;
if (msg != 256)
{
switch (msg)
{
case 276:
case 277:
base.WndProc(ref m);
this.OnScroll();
return;
default:
if (msg == 8270)
{
switch (((Win32.NMHDR)m.GetLParam(typeof(Win32.NMHDR))).code)
{
case -181:
case -180:
base.WndProc(ref m);
this.OnScroll();
return;
default:
base.WndProc(ref m);
return;
}
}
else
{
base.WndProc(ref m);
}
break;
}
}
else
{
Win32.ScrollInfo scrollInfo = new Win32.ScrollInfo();
scrollInfo.fMask = 31;
Win32.GetScrollInfo(base.Handle, 1, scrollInfo);
int nPos = scrollInfo.nPos;
base.WndProc(ref m);
Win32.GetScrollInfo(base.Handle, 1, scrollInfo);
int nPos2 = scrollInfo.nPos;
if (nPos != nPos2)
{
this.OnScroll();
return;
}
}
}
public new void Invalidate()
{
if (_hScrollbarHandle != IntPtr.Zero)
{
// If we've been invalidated, update our drawing code to the new horizontal scrollbar
// position (which is sometimes spontaneously reset to zero and can't be programmatically
// set to its former value) - see CA-11405.
Win32.ScrollInfo si = new Win32.ScrollInfo();
si.fMask = (int)Win32.ScrollInfoMask.SIF_ALL;
si.cbSize = (uint)Marshal.SizeOf(si);
Win32.GetScrollInfo(_hScrollbarHandle, 0, ref si);
_scrollLeft = si.nTrackPos; // often zero
}
base.Invalidate();
}
protected override void WndProc(ref Message m)
{
int msg = m.Msg;
if (msg != 256)
{
switch (msg)
{
case 276:
case 277:
base.WndProc(ref m);
this.OnScroll();
return;
default:
if (msg == 8270)
{
switch (((Win32.NMHDR)m.GetLParam(typeof(Win32.NMHDR))).code)
{
case -181:
case -180:
base.WndProc(ref m);
this.OnScroll();
return;
default:
base.WndProc(ref m);
return;
}
}
else
{
base.WndProc(ref m);
}
break;
}
}
else
{
Win32.ScrollInfo scrollInfo = new Win32.ScrollInfo();
scrollInfo.fMask = 31;
Win32.GetScrollInfo(base.Handle, 1, scrollInfo);
int nPos = scrollInfo.nPos;
base.WndProc(ref m);
Win32.GetScrollInfo(base.Handle, 1, scrollInfo);
int nPos2 = scrollInfo.nPos;
if (nPos != nPos2)
{
this.OnScroll();
return;
}
}
}
