public static XLDate operator -(XLDate d, TimeSpan t)
{
XLDate date = new XLDate(d);
d.AddMilliseconds(-t.TotalMilliseconds);
return(date);
}
public XLDate(XLDate xlDate)
{
_xlDate = xlDate._xlDate;
}
public static object ConvertTo(this object vt, Type toType)
{
if (vt == null)
{
return(GetDefault(toType));
}
Type fromType = vt.GetType();
if (fromType == typeof(DBNull))
{
return(GetDefault(toType));
}
if (fromType == typeof(ExcelDna.Integration.ExcelEmpty) || fromType == typeof(ExcelDna.Integration.ExcelError) || fromType == typeof(ExcelDna.Integration.ExcelMissing))
{
return(GetDefault(toType));
}
if (fromType == typeof(ExcelReference))
{
ExcelReference r = (ExcelReference)vt;
object val = r.GetValue();
return(ConvertTo(val, toType));
}
//acount for nullable types
toType = Nullable.GetUnderlyingType(toType) ?? toType;
if (toType == typeof(DateTime))
{
DateTime dt = DateTime.FromOADate(0.0);
if (fromType == typeof(DateTime))
{
dt = (DateTime)vt;
}
else if (fromType == typeof(double))
{
dt = DateTime.FromOADate((double)vt);
}
else if (fromType == typeof(string))
{
DateTime result;
if (DateTime.TryParse((string)vt, out result))
{
dt = result;
}
}
return(Convert.ChangeType(dt, toType));
}
else if (toType == typeof(XLDate))
{
XLDate dt = 0.0;
if (fromType == typeof(DateTime))
{
dt = (DateTime)vt;
}
else if (fromType == typeof(double))
{
dt = (double)vt;
}
else if (fromType == typeof(string))
{
DateTime result;
if (DateTime.TryParse((string)vt, out result))
{
dt = result;
}
else
{
dt = 0.0;
}
}
else
{
dt = (double)Convert.ChangeType(vt, typeof(double));
}
return(Convert.ChangeType(dt, toType));
}
else if (toType == typeof(double))
{
double dt = 0.0;
if (fromType == typeof(double))
{
dt = (double)vt;
}
else if (fromType == typeof(DateTime))
{
dt = ((DateTime)vt).ToOADate();
}
else if (fromType == typeof(string))
{
double.TryParse((string)vt, out dt);
}
else
{
dt = (double)Convert.ChangeType(vt, typeof(double));
}
return(Convert.ChangeType(dt, toType));
}
else if (toType.IsEnum)
{
try
{
return(Enum.Parse(toType, vt.ToString(), true));
}
catch (Exception)
{
return(GetDefault(toType));
}
}
else
{
return(Convert.ChangeType(vt, toType));
}
}