public class DynamicContractResolver : DefaultContractResolver
{
private readonly char _startingWithChar;
public DynamicContractResolver(char startingWithChar)
{
_startingWithChar = startingWithChar;
}

protected override IList<JsonProperty> CreateProperties(JsonObjectContract contract)
{
IList<JsonProperty> properties = base.CreateProperties(contract);

// only serializer properties that start with the specified character
properties =
properties.Where(p => p.PropertyName.StartsWith(_startingWithChar.ToString())).ToList();

return properties;
}
}

public class Book
{
public string BookName { get; set; }
public decimal BookPrice { get; set; }
public string AuthorName { get; set; }
public int AuthorAge { get; set; }
public string AuthorCountry { get; set; }
}

测试:

Book book = new Book
{
BookName = "The Gathering Storm",
BookPrice = 16.19m,
AuthorName = "Brandon Sanderson",
AuthorAge = 34,
AuthorCountry = "United States of America"
};

string startingWithA = JsonConvert.SerializeObject(book, Formatting.Indented,
new JsonSerializerSettings { ContractResolver = new DynamicContractResolver('A') });
Console.WriteLine(startingWithA);
// {
// "AuthorName": "Brandon Sanderson",
// "AuthorAge": 34,
// "AuthorCountry": "United States of America"
// }

string startingWithB = JsonConvert.SerializeObject(book, Formatting.Indented,
new JsonSerializerSettings { ContractResolver = new DynamicContractResolver('B') });
Console.WriteLine(startingWithA);
// {
// "BookName": "The Gathering Storm",
// "BookPrice": 16.19
// }