Question

仅当主体可以访问这些组件（无论是角色还是基于策略）时，我才想显示导航树的组件。

我对MVC核心并不是特别熟悉，但到目前为止的阅读表明我可以建立一个列表，列出将应用于某个动作的授权过滤器：

    public NavigationNodePermissionResolver(ApplicationModel appModel)
    {
        foreach (var controllerModel in appModel.Controllers)
        {
            var contextFilters = controllerModel.Filters.OfType<IAsyncAuthorizationFilter>().ToList();
            foreach (ActionModel action in controllerModel.Actions)//todo restrain to HttpGet
            {
                var actionFilters = action.Filters.OfType<IAsyncAuthorizationFilter>().ToList();
            }
        }

如何将应用程序模型的实例注入NavigationNodePermissionResolver的实例化器？

NavigationNodePermissionResolver本身将注入：

services.TryAddSingleton<INavigationNodePermissionResolver, NavigationNodePermissionResolver>();

修改

关于这个问题的后续内容 - 当我有一个IAsyncAuthorizationFilters列表是in this so question时该怎么办。

作为后续信息，ApplicationModel是我在this SO answer中发现的ApplicationModelProviderContext的一个属性 - 它似乎与我所追求的大致相同，但它可能是我用来获取的方法然后执行授权过滤器是完全错误的

Answer 1

我发现我可以实例化并注入实现2个接口的同一个实例。我最终在Startup.ConfigureServices：

中

var customAppModelProvider = new CustomApplicationModelProvider();
services.AddSingleton<IApplicationModelProvider>(customAppModelProvider);
services.AddSingleton<IActionFilterMap>(customAppModelProvider);

实施：

public interface IActionFilterMap
{
    IEnumerable<IAsyncAuthorizationFilter> GetFilters(string area, string controller, string action);
}
public class CustomApplicationModelProvider : IApplicationModelProvider, IActionFilterMap
{
    //It will be executed after AuthorizationApplicationModelProvider, which has order -990
    public int Order => 0;

    private ReadOnlyDictionary<ActionKey, IEnumerable<IAsyncAuthorizationFilter>> _authDictionary;

    public IEnumerable<IAsyncAuthorizationFilter> GetFilters(string area, string controller, string action)
    {
        var key = new ActionKey(area, controller, action);
        if (_authDictionary.TryGetValue(key, out IEnumerable<IAsyncAuthorizationFilter> returnVar))
        {
            return returnVar;
        }
        return null;//returning null rather than Enumerable.Empty so consuming method can detect if action found and has no Authorization, or action not found

    }

    public void OnProvidersExecuted(ApplicationModelProviderContext context)
    {
        var returnVar = new Dictionary<ActionKey, IEnumerable<IAsyncAuthorizationFilter>>();
        foreach (var controllerModel in context.Result.Controllers)
        {
            var controllerFilters = controllerModel.Filters.OfType<IAsyncAuthorizationFilter>().ToList();
            string area = controllerModel.Attributes.OfType<AreaAttribute>().FirstOrDefault()?.RouteValue;
            foreach (ActionModel action in controllerModel.Actions)//todo restrain to get
            {
                var method = action.Attributes.OfType<HttpMethodAttribute>().FirstOrDefault();
                if (method == null || method.HttpMethods.Contains("GET"))
                {
                    var key = new ActionKey(area, controllerModel.ControllerName, action.ActionName);
                    if (action.Filters.OfType<AllowAnonymousFilter>().Any())
                    {
                        returnVar.Add(key, Enumerable.Empty<IAsyncAuthorizationFilter>());
                    }
                    else
                    {
                        var filters = controllerFilters.Concat(action.Filters.OfType<IAsyncAuthorizationFilter>()).ToArray();
                        returnVar.Add(key, filters);
                    }
                }
            }
            _authDictionary = new ReadOnlyDictionary<ActionKey, IEnumerable<IAsyncAuthorizationFilter>>(returnVar);
        }
    }

    public void OnProvidersExecuting(ApplicationModelProviderContext context)
    {
        //empty
    }

    private class ActionKey : Tuple<string, string, string>
    {
        public ActionKey(string area, string controller, string action) : base(area ?? string.Empty, controller, action)
        {
            _hashCode = base.GetHashCode();
        }

        int _hashCode;
        public override int GetHashCode()
        {
            return _hashCode;
        }
    }
}

将ApplicationModel的实例注入到MVC服务中，该服务本身就是一个单例

1 个答案: