如何使 DateTime 不需要？

Question

I have this model for an app that tracks our migration status for users. If they haven't been migrated, there's no migration date. So, how can they leave that field blank? It's not annotated as required, yet validation fails as if it is required. I cannot seem to set it to null either. How does one get around this problem?

[Display(Name = "Migrated?")]
public bool migrated { get; set; }

[Display(Name = "Date Migrated")]
public DateTime migrationdate { get; set; }

Answer 1

Use a nullable type

[Display(Name = "Migrated?")]
public bool migrated { get; set; }

[Display(Name = "Date Migrated")]
public DateTime? migrationdate { get; set; }