[转][C#]Json.Net 设置项

1、忽略 Null

JsonSerializerSettings jsetting=new JsonSerializerSettings();
 jsetting.NullValueHandling = NullValueHandling.Ignore;

2、将 Null 输出为 string.Empty

var settings = new JsonSerializerSettings() { ContractResolver= new NullToEmptyStringResolver() };
var str = JsonConvert.SerializeObject(yourObj, settings);

public class NullToEmptyStringResolver : Newtonsoft.Json.Serialization.DefaultContractResolver
{
    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        return type.GetProperties()
                .Select(p=>{
                    var jp = base.CreateProperty(p, memberSerialization);
                    jp.ValueProvider = new NullToEmptyStringValueProvider(p);
                    return jp;
                }).ToList();
    }
}

public class NullToEmptyStringValueProvider : IValueProvider
{
    PropertyInfo _MemberInfo;
    public NullToEmptyStringValueProvider(PropertyInfo memberInfo)
    {
        _MemberInfo = memberInfo;
    }

    public object GetValue(object target)
    {
        object result =  _MemberInfo.GetValue(target);
        if (_MemberInfo.PropertyType == typeof(string) && result == null) result = "";
        return result;

    }

    public void SetValue(object target, object value)
    {
        _MemberInfo.SetValue(target, value);
    }
}

网上看到有全局设置如下，也能通过编译，但貌似没有效果：

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;