null 值不能分配给 System.DateTime 类型的成员，该类型是不可为空的值类型

Question

var Ceremony = dc.GetOneCeremony(IdCeremony);

when run the top line show this error:

The null value cannot be assigned to a member with type System.DateTime which is a non-nullable value type.

Answer 1

if you have a property Ceremony class that has DateTime type change it to DateTime? it seems GetOneCeremony returns an object that has null datetime field

Answer 2

you're probably assigning a null value from a datareader to a datatime datatype.
something like:

DateTime dt = (DateTime)yourDataReader["YourDateTimeColumnWhichIsNull"].Value