AcceptChanges无法继续，因为对象的键值与ObjectStateManager中的另一个对象冲突

The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges.The changes to the database were committed succ