C＃父子列表添加ID

Question

I have a parent child list which I get as JSON

public class Item
{
    public Item()
    {
       this.Items = new List<Item>();
    }

    public string Name { get; set; }
    public DateTime Created { get; set; }
    public string Content { get; set; }
    public string UserId { get; set; }
    List<Item> Items { get; set; }
}

Now imagine I get a JSON that I will deserialize into

 string json = "json in here"

 List<Item> listItems = JsonConvert.Dezerialize<List<Item>>(json);

My question: how can I parse the List<Item> and add dynamically ID's to it so it will be something like this?

public class Item
{
    public Item()
    {
       this.Items = new List<Item>();
    }

    public string Id { get; set; }
    public string ParentId { get; set; }
    public string Name { get; set; }
    public DateTime Created { get; set; }
    public string Content { get; set; }
    public string UserId { get; set; }
    List<Item> Items { get; set; }
}

The Id is the item Id (can be Guid for example) and ParentId is the Id of the parent for the item. If Item has no parent then ParentId is null. If ParentId is null Item is then top item. There can be more then one parent items.

Answer 1

can be Guid for example

That makes this a lot easier, since you don't have to keep track of which IDs have been used. Now it's a simple job for recursion:

void SetIDs(Item item, string parentId)
{
    item.ParentId = parentId;
    item.Id = Guid.NewGuid().ToString();
    foreach (var i in item.Items)
        SetIDs(i, item.Id);
}

Then just call it with an initial empty ID for the top-level item (per your requirement that the top-level has a null parent ID):

SetIDs(someItem, null);

(If you did have to track the IDs, such as with an int for example, then you'd likely either be looking at a higher-scoped variable which can be tricky or out parameters or something of that nature which can be ugly.)