How can I convert a class into Dictionary<string,string>?

This is the recipe: 1 reflection, 1 LINQ-to-Objects!

 someObject.GetType()
     .GetProperties(BindingFlags.Instance | BindingFlags.Public)
          .ToDictionary(prop => prop.Name, prop => (string)prop.GetValue(someObject, null))

Since I published this answer I've checked that many people found it useful. I invite everyone looking for this simple solution to check another Q&A where I generalized it into an extension method: Mapping object to dictionary and vice versa

Here a example with reflection without LINQ:

    Location local = new Location();
    local.city = "Lisbon";
    local.country = "Portugal";
    local.state = "None";

    PropertyInfo[] infos = local.GetType().GetProperties();

    Dictionary<string,string> dix = new Dictionary<string,string> ();

    foreach (PropertyInfo info in infos)
    {
        dix.Add(info.Name, info.GetValue(local, null).ToString());
    }

    foreach (string key in dix.Keys)
    {
        Console.WriteLine("nameProperty: {0}; value: {1}", key, dix[key]);
    }

    Console.Read();

I would like to add an alternative to reflection, using JToken. You will need to check the benchmark difference between the two to see which has better performance.

var location = new Location() { City = "London" };
var locationToken = JToken.FromObject(location);
var locationObject = locationObject.Value<JObject>();
var locationPropertyList = locationObject.Properties()
    .Select(x => new KeyValuePair<string, string>(x.Name, x.Value.ToString()));

Note this method is best for a flat class structure.

public static Dictionary<string, object> ToDictionary(object model)
    {
        var serializedModel = JsonModelSerializer.Serialize(model);
        return JsonModelSerializer.Deserialize<Dictionary<string, object>>(serializedModel);
    }

I have used the above code. As simplified as possible and it works without reflection and the model could be nested and still work. (Change your code to not use Newtonsoft if you are using Json.net)

Give this a try.

This uses reflection to retrieve the object type, then all of the properties of the supplied object (PropertyInfo prop in obj.GetType().GetProperties(), see https://docs.microsoft.com/en-us/dotnet/api/system.type.getproperties?view=netcore-3.1). It then adds the property name as a key in the dictionary and, if a value exists, it adds the value, otherwise it adds null.

    public static Dictionary<string, object> ObjectToDictionary(object obj)
    {
        Dictionary<string, object> ret = new Dictionary<string, object>();

        foreach (PropertyInfo prop in obj.GetType().GetProperties())
        {
            string propName = prop.Name;
            var val = obj.GetType().GetProperty(propName).GetValue(obj, null);
            if (val != null)
            {
                ret.Add(propName, val);
            }
            else
            {
                ret.Add(propName, null);
            }
        }

        return ret;
    }