我正在尝试创建一个自定义RoleValidator对象,以验证我的自定义IdentityRole.我创建了一个继承自RoleValidator的ApplicaitonRoleValidator类,并将其设置为我的ApplicationRoleManager类中的RoleValidator.但是,当我创建新角色时,永远不会调用验证函数ValidateAsync.

我试过看实现UserValidator的类似问题,如How can customize Asp.net Identity 2 username already taken validation message?
而这个ASP.NET Identity – setting UserValidator does nothing却无法正常工作.

/// <summary>
/// Custom role validator, used to validate new instances of ApplicationRole that are added to the system.
/// </summary>
/// <typeparam name="TRole">The type of the role.</typeparam>
public class ApplicationRoleValidator<TRole> : RoleValidator<TRole> where TRole : ApplicationRole
{
    private RoleManager<TRole, string> Manager { get; set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="ApplicationRoleValidator" /> class.
    /// </summary>
    /// <param name="manager">The manager.</param>
    public ApplicationRoleValidator(RoleManager<TRole, string> manager) : base(manager)
    {
        Manager = manager;
    }

    /// <summary>
    /// Validates a role before saving.
    /// </summary>
    /// <param name="item"></param>
    /// <returns></returns>
    /// <exception cref="System.ArgumentNullException">item</exception>
    public override async Task<IdentityResult> ValidateAsync(TRole item)
    {
        if (item == null)//<= break point here never reached.
        {
            throw new ArgumentNullException(nameof(item));
        }

        var rslt = base.ValidateAsync(item);
        if (rslt.Result.Errors.Any())
        {//return error if found
            return IdentityResult.Failed(rslt.Result.Errors.ToArray());
        }

        var errors = new List<string>();
        //validate the min num of members
        if (role.MinimumNumberOfMembers < 0)
        {
            errors.Add(string.Format(CultureInfo.CurrentCulture, "最小数は0以上でなければなりません."));
        }

        return errors.Count > 0 ? IdentityResult.Failed(errors.ToArray()) : IdentityResult.Success;
    }
}

在创建过程中设置自定义RoleValidator的ApplicationRoleManager.我可以在那条线上中断,这样我就知道它正在被调用.

public class ApplicationRoleManager : RoleManager<ApplicationRole, string>
{
    /// <summary>
    /// Initializes a new instance of the <see cref="ApplicationRoleManager"/> class.
    /// </summary>
    /// <param name="store"></param>
    public ApplicationRoleManager(IRoleStore<ApplicationRole, string> store)
        : base(store)
    {
    }
    /// <summary>
    /// Creates the specified options.
    /// </summary>
    /// <param name="options">The options.</param>
    /// <param name="context">The context.</param>
    /// <returns></returns>
    public static ApplicationRoleManager Create(IdentityFactoryOptions<ApplicationRoleManager> options, IOwinContext context)
    {
        var manager = new ApplicationRoleManager(new ApplicationRoleStore(context.Get<MyContext>()));
        manager.RoleValidator = new ApplicationRoleValidator<ApplicationRole>(manager);
        return manager;
    }
}
public class ApplicationRole : IdentityRole<string, ApplicationUserRole>
{
    public bool IsSystemGroup { get; set; }
    public string Description { get; set; } = "";
    public int MinimumNumberOfMembers { get; set; }
}

public class ApplicationRoleStore : RoleStore<ApplicationRole, string, ApplicationUserRole>
{
    public ApplicationRoleStore(MyContext context)
        : base(context)
    {
    }
}

通过在ApplicationRoleManager上调用Create来创建角色

var store = new ApplicationRoleStore(new MyContext());
var manager = new ApplicationRoleManager(store);
manager.Create(group);

解决方法:

您正在ApplicationRoleManager的Create方法中将ApplicationRoleValidator设置为ApplicationRoleManager的RoleValidator.在发布的最后3行代码中,您正在更新ApplicationRoleManager的实例. ApplicationRoleManager的此实例获取默认的RoleValidator.

如果要新建ApplicationRoleManager的实例,则必须将该逻辑放入构造函数中

public ApplicationRoleManager(IRoleStore<ApplicationRole, string> store) : base(store)
{
     RoleValidator = new ApplicationRoleValidator<ApplicationRole>(this);
}