private bool InspectScrollBarAndTriggerEventIfNeeded()
{
bool ret = false;
NativeMethods.Scrollinfo scrollinfo = new NativeMethods.Scrollinfo
{
Size = (uint)Marshal.SizeOf(typeof(NativeMethods.Scrollinfo)),
Mask = (uint)Convert.ToInt32(ScrollInfoMask.SIF_ALL)
};
bool success = NativeMethods.GetScrollInfo(Handle, SB_VERT, ref scrollinfo);
if (!success)
{
return(false);
}
if (ScrollInfoChanged(scrollinfo))
{
OnScrollValueChanged(scrollinfo);
}
if (scrollinfo.Position == 0)
{
OnScrollLimit(ScrollLimit.FirstLine);
ret = true;
}
if (scrollinfo.Position + scrollinfo.Page - 1 == scrollinfo.Max)
{
OnScrollLimit(ScrollLimit.LastLine);
ret = true;
}
lastScrollinfo = scrollinfo;
return(ret);
}
private void OnScrollValueChanged(NativeMethods.Scrollinfo scrollinfo)
{
if (ScrollValueChanged == null)
{
return;
}
var value = new ScrollValueEventArgs(scrollinfo.Min, scrollinfo.Max, scrollinfo.Position);
ScrollValueChanged(this, value);
}
private bool ScrollInfoChanged(NativeMethods.Scrollinfo scrollinfo)
{
if (lastScrollinfo.HasValue == false)
{
return(true);
}
if (scrollinfo.Position != lastScrollinfo.Value.Position)
{
return(true);
}
return(false);
}
private void SetScrollBar()
{
int sizeOfFile = 10000000;
int positionInFile = sizeOfFile / 2;
NativeMethods.Scrollinfo scrollinfo = new NativeMethods.Scrollinfo();
scrollinfo.Size = (uint)Marshal.SizeOf(typeof(NativeMethods.Scrollinfo));
scrollinfo.Mask = (uint)Convert.ToInt32(ScrollInfoMask.SIF_ALL);
scrollinfo.Min = 0;
scrollinfo.Max = sizeOfFile; // for example the number of items in the control
scrollinfo.Position = positionInFile;
scrollinfo.Page = 1;
bool redraw = true;
int scrollBoxPosition = NativeMethods.SetScrollInfo(Handle, SB_VERT, ref scrollinfo, redraw);//The return value is the current position of the scroll box.
}
