你可以使用[ScriptIgnore]:

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    [ScriptIgnore]
    public bool IsComplete
    {
        get { return Id > 0 && !string.IsNullOrEmpty(Name); }
    }
}

在这种情况下，Id和名称只会被序列化

抱歉，我决定再写一个答案，因为其他答案都不能复制粘贴。

如果你不想用一些属性装饰属性，或者如果你无法访问类，或者如果你想决定在运行时序列化什么，等等，等等，这里是你如何在Newtonsoft做它。Json

//short helper class to ignore some properties from serialization
public class IgnorePropertiesResolver : DefaultContractResolver
{
    private readonly HashSet<string> ignoreProps;
    public IgnorePropertiesResolver(IEnumerable<string> propNamesToIgnore)
    {
        this.ignoreProps = new HashSet<string>(propNamesToIgnore);
    }

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        JsonProperty property = base.CreateProperty(member, memberSerialization);
        if (this.ignoreProps.Contains(property.PropertyName))
        {
            property.ShouldSerialize = _ => false;
        }
        return property;
    }
}

使用

JsonConvert.SerializeObject(YourObject, new JsonSerializerSettings()
        { ContractResolver = new IgnorePropertiesResolver(new[] { "Prop1", "Prop2" }) });

注意:如果您决定使用这个答案，请确保缓存ContractResolver对象，否则性能可能会受到影响。

我在这里发布了代码，以防有人想要添加任何东西

https://github.com/jitbit/JsonIgnoreProps

如果你不像我一样热衷于用属性装饰代码，尤其是当你不能在编译时告诉你会发生什么，这是我的解决方案。

使用Javascript序列化器

public static class JsonSerializerExtensions
{
    public static string ToJsonString(this object target,bool ignoreNulls = true)
    {
        var javaScriptSerializer = new JavaScriptSerializer();
        if(ignoreNulls)
        {
            javaScriptSerializer.RegisterConverters(new[] { new PropertyExclusionConverter(target.GetType(), true) });
        }

        return javaScriptSerializer.Serialize(target);
    }
        
    public static string ToJsonString(this object target, Dictionary<Type, List<string>> ignore, bool ignoreNulls = true)
    {
        var javaScriptSerializer = new JavaScriptSerializer();
        foreach (var key in ignore.Keys)
        {
            javaScriptSerializer.RegisterConverters(new[] { new PropertyExclusionConverter(key, ignore[key], ignoreNulls) });
        }
        return javaScriptSerializer.Serialize(target);
    }
 }
    
    
public class PropertyExclusionConverter : JavaScriptConverter
{
    private readonly List<string> propertiesToIgnore;
    private readonly Type type;
    private readonly bool ignoreNulls;
    
    public PropertyExclusionConverter(Type type, List<string> propertiesToIgnore, bool ignoreNulls)
    {
        this.ignoreNulls = ignoreNulls;
        this.type = type;
        this.propertiesToIgnore = propertiesToIgnore ?? new List<string>();
    }
    
    public PropertyExclusionConverter(Type type, bool ignoreNulls)
        : this(type, null, ignoreNulls){}
    
    public override IEnumerable<Type> SupportedTypes
    {
        get { return new ReadOnlyCollection<Type>(new List<Type>(new[] { this.type })); }
    }
    
    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
       var result = new Dictionary<string, object>();
       if (obj == null)
       {
           return result;
       }
       var properties = obj.GetType().GetProperties();
       foreach (var propertyInfo in properties)
       {
           if (!this.propertiesToIgnore.Contains(propertyInfo.Name))
           {
               if(this.ignoreNulls && propertyInfo.GetValue(obj, null) == null)
               {
                     continue;
               }
               result.Add(propertyInfo.Name, propertyInfo.GetValue(obj, null));
           }
        }
        return result;
    }
    
    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        throw new NotImplementedException(); //Converter is currently only used for ignoring properties on serialization
    }
}

你可以使用[ScriptIgnore]:

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    [ScriptIgnore]
    public bool IsComplete
    {
        get { return Id > 0 && !string.IsNullOrEmpty(Name); }
    }
}

在这种情况下，Id和名称只会被序列化

您也可以使用[NonSerialized]属性

[Serializable]
public struct MySerializableStruct
{
    [NonSerialized]
    public string hiddenField;
    public string normalField;
}

来自微软文档:

指示可序列化类的字段不应被序列化。这个类不能被继承。

例如，如果你使用Unity(这不仅仅适用于Unity)，那么这适用于UnityEngine。JsonUtility

using UnityEngine;

MySerializableStruct mss = new MySerializableStruct 
{ 
    hiddenField = "foo", 
    normalField = "bar" 
};
Debug.Log(JsonUtility.ToJson(mss)); // result: {"normalField":"bar"}

对于c# 9的记录，它是[property: JsonIgnore]

using System.Text.Json.Serialization;

public record R(
   string Text2
   [property: JsonIgnore] string Text2)

对于经典样式，它仍然只是[JsonIgnore]。

using System.Text.Json.Serialization;

public record R
{
   public string Text {get; init; }

   [JsonIgnore] 
   public string Text2 { get; init; }
}