RE：MVC5 C＃当前日期时间查询

Question

I'm trying to get my posts to have a preset datetime field but when I go to edit my posts they are set to 01/01/2015 00:00 whereas i'd rather have them be automated to be like 14/07/2015 13:53 (or whatever the current datetime is). I thought adding a line above my datetime property like [DateTime.current] or something along those lines might work but I've not been successful yet.

public class Post
{
    public int PostID { get; set; }
    public Guid UserID { get; set; }
    public int ThreadID { get; set; }
    public string PostTitle { get; set; }
    public DateTime PostDateTime { get; set; }
    public string PostBody { get; set; }
}

Answer 1

If this is your model, you could use the default constructor.

public class Post
{
    public int PostID { get; set; }
    public Guid UserID { get; set; }
    public int ThreadID { get; set; }
    public string PostTitle { get; set; }
    public DateTime PostDateTime { get; set; }
    public string PostBody { get; set; }

    public Post()
    {
       PostDateTime = DateTime.Now;
    }
}

Model binding occurs after the model has been created, so it won't affect MVC.

Answer 2

Why not add a constructor to your Post class and pass the initial value you want your post to be initialized with ?

public class Post
{
    public int PostID { get; set; }
    public Guid UserID { get; set; }
    public int ThreadID { get; set; }
    public string PostTitle { get; set; }
    public DateTime PostDateTime { get; set; }
    public string PostBody { get; set; }

    public Post( DateTime initialValue)
    {
         PostDateTime = initialValue;
    }
}

Answer 3

Set the default DateTime that you would like in the constructor

public class Post
{
    public Post()
    {
        PostDateTime = DateTime.Now;
    }

    public int PostID { get; set; }
    public Guid UserID { get; set; }
    public int ThreadID { get; set; }
    public string PostTitle { get; set; }
    public DateTime PostDateTime { get; set; }
    public string PostBody { get; set; }
}

When this model is bound on the server side from values submitted by the client side, a Post instance will be created with a PostDateTime value as set in the constructor, but then this value will be overridden by the model binding process and set to the value submitted by the client, since PostDateTime is a property with a public setter.