Exclude certain fields when returning as json

问题

I have an asp.net web api application.

For now lets say that the application consists of a User entity and a Post entity. A post is written by a user, so every post entity contains a reference to the user entity.

class Post {

    public int Id { get; set; }

    public string Title  { get; set; }

    public string Content { get; set; }

    public User User { get; set; } // Reference to the user that wrote the post
} 

The problem is when i want to return a list of posts as Json. I don't want to include the writers of the posts inside the list, in other words, i want to exclude the User field from the list of posts.

Example:

[
    {
        "Id": 1,
        "Title": "Post A",
        "Content": "..."
    },
    {
        "Id": 2,
        "Title": "Post B",
        "Content": "..."
    }
]

I know that i can do it easily by creating a new class called JsonPost without the User field and then converting the list of Post's to a list of JsonPost's with linq, but i want to solve it without creating a new class.

Thanks, Arik

回答1:

Just mark Post's User property with [JsonIgnore] attribute from Newtonsoft.Json namespace and it won't be serialized

using Newtonsoft.Json;
class Post {

    public int Id { get; set; }

    public string Title  { get; set; }

    public string Content { get; set; }

    [JsonIgnore]
    public User User { get; set; } // This property won't be serialized
} 

回答2:

Since you don't want to create a view model another way would be by using projection. Or creating a dynamic object.

来源：https://stackoverflow.com/questions/32037555/exclude-certain-fields-when-returning-as-json