I am trying to simulate a foreign key behaviour using JSON.Net but I can't seem to find a way to have the real references.
Let's say I have this simple example:
private static void Main(string[] args)
{
var g1 = new Group {Name = "g1"};
var g2 = new Group {Name = "g2"};
var users = new[]
{
new User{ Username = "truc", Group = g1 },
new User{ Username = "machin", Group = g2 },
new User{ Username = "dom", Group = g2 },
new User{ Username = "boum", Group = g2 }
};
string json = JsonConvert.SerializeObject(users);
var jsonUsers = JsonConvert.DeserializeObject<User[]>(json);
Console.WriteLine(jsonUsers[2].Group == jsonUsers[3].Group);
Console.ReadLine();
}
the problem here is that Console.WriteLine(jsonUsers[2].Group == jsonUsers[3].Group);
is always false.
The only way I found that would make it work would be to store a list of users, then a list of group and having a GroupId proprety Inside of users. Then after everything is deserialized, I manually insert references of groups Inside of users. It's hackish.
What would be the best way to approach this problem ?
You are making the instance-comparison. you should override Equals
and GetHashcode
in Group
class. Operator overloading would also be good since you use ==
operator in Console.WriteLine
Otherwise;
new Group() { Name = "a" } == new Group() { Name = "a" }
or
new Group() { Name = "a" }.Equals(new Group() { Name = "a" })
would always return false
.
public class Group
{
public string Name;
public int i;
public static bool operator ==(Group a, Group b)
{
return a.Equals(b);
}
public static bool operator !=(Group a, Group b)
{
return !(a.Name == b.Name);
}
public override bool Equals(object obj)
{
var g = obj as Group;
if (ReferenceEquals(this,g)) return true;
return g.Name.Equals(Name);
}
public override int GetHashCode()
{
return Name.GetHashCode();
}
}
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