public CostHistory Compare(Share x, Share y)
{
if (ReferenceEquals(x, y))
{
return(null);
}
if (ReferenceEquals(x, null))
{
return(null);
}
if (ReferenceEquals(y, null))
{
return(null);
}
if (x.GetType() != y.GetType())
{
return(null);
}
return(new CostHistory((Math.Round(double.Parse(x.CheckTime)
- double.Parse(y.CheckTime)), 2).ToString(), x.Cost,
(Math.Round(double.Parse(x.Cost) - double.Parse(y.Cost)), 2).ToString()));
}