[程式開發技巧,] ASP.NET Core 動態忽略JSON物件屬性 | JSON.NET

這篇簡單分享在JSON轉換中
如何動態忽略物件的屬性

[ Resolver類別 ]

public class IgnorePeopertiesResolver : CamelCasePropertyNamesContractResolver
{
    public static List<string> PropertyNames { get; } = new List<string>();

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        JsonProperty p = base.CreateProperty(member, memberSerialization);
        foreach (string name in PropertyNames)
        {
            if (p.PropertyName.ToLower() == name.ToLower())
            {
                p.Ignored = true;
            }
        }
        return p;
    }
}

[  Extension類別 ]

public static class JsonIgnorePropertyExtension
{
    public static void AddIgnoreProperties<T>(this T[] arr, Func<T, string[]> callback)
    {
        IgnorePeopertiesResolver.PropertyNames.Clear();
        if (arr.Length > 0)
        {
            IgnorePeopertiesResolver.PropertyNames.AddRange(callback(arr[0]));
        }
    }

    public static void AddIgnoreProperties<T>(this T obj, params string[] names)
    {
        IgnorePeopertiesResolver.PropertyNames.Clear();
        IgnorePeopertiesResolver.PropertyNames.AddRange(names);
    }
}

[ Services DI ]

services.AddControllers().AddNewtonsoftJson(setup => 
{
    setup.SerializerSettings.ContractResolver = new IgnorePeopertiesResolver();
});

[ 使用示範 ]

someArray.AddIgnoreProperties(data => { return new string[] { nameof(data.Account) }; });
return Ok(someArray);

someObject.AddIgnoreProperties(nameof(someObject.Password));
return Ok(someObject);

主要是透過static與extension完成整個流程

在回傳ActionResult之前呼叫AddIgnoreProperties方法

JSON在序列化時就會判斷哪些屬性名稱是要忽略的