Try something like this
if (e.Row.RowType == DataControlRowType.DataRow)
{
YourClass object = (YourClass)e.Row.DataItem;
LinkButton lnkbtn= (LinkButton)e.Row.FindControl("Lnk");
lnkbtn.Visible = !Convert.ToBoolean(object.Value);
}
Well, This will do the job for you as per your current implementation. use a
Not ( ! ) Operator
<br />
Visible=<%# !(Convert.ToBoolean(Eval("IsNewRow"))) %>
Let me know if it work.