how to avoid uitableview cell refresh flicker when reload cell - uitableview

Question

I used the monotouch.dialog to develop one PrivateMsg talk screen. But when I reload the cell , the cell flicker, how to avoid it ?
add new pm msg accross 2 step: 1. append a element cell: State.Insert(msg is sending)=> 2. reload the element cell status: State.Updated(msg send sucessced)
Pls find the attachment:screen recording file and the source code:
void HandleOnPMChanged(object sender, PMChangedEventArgs e)
{
if (e.PMSID != this.mPMSession.PMSID)
return;
this.BeginInvokeOnMainThread(() =>
{
if (e. State == State.Insert) //step1
{
element = this.GetNewPMElement(itemData);
pmSection.Add(element);
this.ScrollToBottomRow();
} else if (e.State == State.Update && e.PM != null) //step2
{
var element = FindElement(e.PM.Guid.GetHashCode());
if (element != null)
{
var indexPaths = new NSIndexPath [] { element.IndexPath };
this.TableView.ReloadRows(indexPaths, UITableViewRowAnimation.None); //this line will flicker
//remark: this.ScrollToBottomRow();
}
}
else if (e. State == State.Insert)
{
element = this.GetNewPMElement(itemData);
pmSection.Add(element);
this.ScrollToBottomRow(); //step1
}
});
}
public void ScrollToBottomRow()
{
try
{
if (pmSection.Count < 1)
return;
NSIndexPath ndxPath = pmSection[pmSection.Count - 1].IndexPath;
if (ndxPath != null)
this.TableView.ScrollToRow(ndxPath, UITableViewScrollPosition.Bottom, false); //Bottom, false);
}
catch (Exception ex)
{
Util.ReportMsg("PMDVC ScrollToBottomRow Exception:", ex.Message);
}
}

Answer 1

issue has been fixed.
EstimatedHeight return bigger than actual value.