在 .NET Core 使用 Feature Flag (Feature Toggle) - 自訂邏輯
Feature Flag 是否開啟，也可以透過自訂的類別來撰寫，可以透過IFeatureFilter來實現，以下範例以取得使用者 User-Agent 為例 實作IFeatureFilter，新增一個 BrowserFeatureFilter.cs 檔案 [FilterAlias("Browser")] public class BrowserFeatureFilter : IFeatureFilter { private readonly IHttpContextAccessor _httpContextAccessor; public BrowserFeatureFilter(IHttpContextAccessor httpContextAccessor) { _httpContextAccessor = httpContextAccessor; } public Task<bool> EvaluateAsync(FeatureFilterEvaluationContext context) { // 取得Request的瀏覽器類型 var agent = _httpContextAccessor.HttpContext.Request.Headers["User-Agent"].ToString(); // 取得 appSettings.json的設定 var settings = context.Parameters.Get<BrowserFilterSettings>(); // TODO: 這邊就可以撰寫邏輯驗證是否針對該瀏覽器開此功能 return Task.FromResult<bool>(false); } } public class BrowserFilterSettings { public string[] Allowed { get; set; } } appsettings.json (允許Edge瀏覽器開啟FeatureA功能) "FeatureManagement": { "FeatureA": { "EnabledFor": [ { "Name": "Browser", "Parameters": { "Allowed": [ "Edg" ] } } ] } } startup 注入 services....