優化可重復的匿名委托 C#

Question

我注冊授權策略。 聲明options它是站點上的一系列能力用戶['cm', 'wtm', 'um'] 。 借助 RequireAssertion 檢查可用性所需的能力。 我如何優化這個可重復的代碼？ 謝謝！

    policyBuilder.AddPolicy("UmPolicy", policy =>
    {
        policy.RequireAssertion(context =>
        {
            var optionsSerializedArray = context.User.FindFirstValue(ClaimType.Options);

            if (optionsSerializedArray == null)
            {
                return false;
            }

            var deserializedOptionsUser = JsonSerializer.Deserialize<string[]>(optionsSerializedArray);
            var option = deserializedOptionsUser?.SingleOrDefault(value => value == "um");

            return option != null;
        });
    });

    policyBuilder.AddPolicy("CmPolicy", policy =>
    {
        policy.RequireAssertion(context =>
        {
            var optionsSerializedArray = context.User.FindFirstValue(ClaimType.Options);

            if (optionsSerializedArray == null)
            {
                return false;
            }

            var deserializedOptionsUser = JsonSerializer.Deserialize<string[]>(optionsSerializedArray);
            var option = deserializedOptionsUser?.SingleOrDefault(value => value == "cm");

            return option != null;
        });

        policyBuilder.AddPolicy("WtmPolicy", policy =>
        {
            policy.RequireAssertion(context =>
            {
                var optionsSerializedArray = context.User.FindFirstValue(ClaimType.Options);

                if (optionsSerializedArray == null)
                {
                    return false;
                }

                var deserializedOptionsUser = JsonSerializer.Deserialize<string[]>(optionsSerializedArray);
                var option = deserializedOptionsUser?.SingleOrDefault(value => value == "wtm");

                return option != null;
            });
        });

Answer 1

您可以使用字典來存儲所有策略名稱，並在字典項的循環中編寫代碼。

Dictionary<string, string> policies = new() { { "UmPolicy", "um" }, { "CmPolicy", "cm" }, { "WtmPolicy", "wtm" } };

foreach(var item in policies)
{
    policyBuilder.AddPolicy(item.Key, policy =>
    {
        policy.RequireAssertion(context =>
        {
            var optionsSerializedArray = context.User.FindFirstValue(ClaimType.Options);

            if (optionsSerializedArray == null)
            {
                return false;
            }

            var deserializedOptionsUser = JsonSerializer.Deserialize<string[]>(optionsSerializedArray);
            var option = deserializedOptionsUser?.SingleOrDefault(value => value == item.Value);

            return option != null;
        });
    });
}