在C＃中将json文件反序列化为静态类

Question

I have a static class with static fields and a json.

I can deserialize the json into a dynamic object, so I have all the fields and they match exactly the static fields in the class.

How can I use reflection to enumerate the fields and copy the values from the dynamic class into the static class fields?

I can't change the architecture, make it a singleton, etc; it's shared code and the class is going to remain static since it's globally shared settings object used by a shared library.

The solution needs to use reflection since the class evolves over time with new members. Otherwise I could have written a custom deserializer.

---

Adding more details, but there is really not much:

I have this static class:

static class A
{
    static int I;
    static string S;
}

and a json matching the fields exactly:

{
    "I" : 3,
    "S" : "hello"
}

var Data = JsonConvert.Deserialize<dynamic>(...);

I would like to initialize the static fields of class A with the values I deserialized from the json, into a dynamic object.

---

Another edit:

I came up with something similar to what David wrote, but this is less efficient since I use the deserializer to convert types, so David's solution is better.

here's what I came up with:

foreach (var Destination in typeof(Settings).GetProperties())
{
    var Name = Destination.Name;
    var T = Destination.PropertyType;
    var Value = JsonConvert.DeserializeObject("\"" + JT[Name] + "\"", T);
    Destination.SetValue(null, Value);
}

Answer 1

You can do this quite easily by having a matching non-static class, getting the properties of source and destination and looping through each one. For example, assuming we have two classes:

public static class A
{
    public static int I { get; set; }
    public static string S { get; set; }
}

public class B
{
    public int I { get; set; }
    public string S { get; set; }
}

We can now do this:

public void MapToStaticClass(B source)
{
    var sourceProperties = source.GetType().GetProperties();

    //Key thing here is to specify we want the static properties only
    var destinationProperties = typeof(A)
        .GetProperties(BindingFlags.Public | BindingFlags.Static);

    foreach (var prop in sourceProperties)
    {
        //Find matching property by name
        var destinationProp = destinationProperties
            .Single(p => p.Name == prop.Name);

        //Set the static property value
        destinationProp.SetValue(null, prop.GetValue(source));
    }
}

Another option is to deserialise to JToken and use that combined with reflection:

var source = JsonConvert.DeserializeObject<JToken>(json);

And then:

public void MapJTokenToStaticClass(JToken source)
{
    var destinationProperties = typeof(A)
        .GetProperties(BindingFlags.Public | BindingFlags.Static);

    foreach (JProperty prop in source)
    {
        var destinationProp = destinationProperties
            .SingleOrDefault(p => p.Name.Equals(prop.Name, StringComparison.OrdinalIgnoreCase));
        var value = ((JValue)prop.Value).Value;

        //The ChangeType is required because JSON.Net will deserialise
        //numbers as long by default
        destinationProp.SetValue(null, Convert.ChangeType(value, destinationProp.PropertyType));
    }
}