c# - 删除用户的声明

Question

我将 ASP.NET Identity (v2) 与 Entity Framework 结合使用。我正在构建一个包含多个复选框的页面，每个复选框代表一个声明。单击按钮(在我的示例中为 SavePrivileges 函数)我想根据复选框的状态调整给定用户的声明，即删除未选中的声明，并添加声明，这已检查。

添加声明工作正常。但是，我似乎无法删除用户的声明。在调用 manager.RemoveClaim 时，我得到一个 InvalidOperationException 说集合已经改变。即使我不修改 user.Claims 集合，我实际上也会遇到此异常。

这是我简化的示例场景:

    protected void SavePrivileges(string userId)
    {
        const string claim1Type = "...";
        const string claim2Type = "...";
        const string claim1Value = "...";
        const string claim2Value = "...";

        var store = new UserStore<IdentityUser>();
        var manager = new UserManager<IdentityUser>(store);
        var user = manager.FindById(userId);

        // Lists to keep track of changes
        var removed = new List<Claim>();
        var added = new List<Claim>();

        bool claim1Checked = CheckBox1.Checked;
        bool claim2Checked = CheckBox2.Checked;

        bool claim1Possesed = user.Claims.FirstOrDefault(claim => claim.ClaimValue == claim1Value &&
                                                                  claim.ClaimType  == claim1Type) != null;
        bool claim2Possesed = user.Claims.FirstOrDefault(claim => claim.ClaimValue == claim2Value &&
                                                                  claim.ClaimType  == claim2Type) != null;

        if (claim1Checked && !claim1Possesed)
        {
            added.Add(new Claim(claim1Type, claim1Value));
        }
        else if (!claim1Checked && claim1Possesed)
        {
            removed.Add(new Claim(claim1Type, claim1Value));
        }
        // + The same for claim2...

        // Remove extra claims
        foreach (Claim claim in removed)
        {
            manager.RemoveClaim(user.Id, claim);
        }
        // Add new claims
        foreach (Claim claim in added)
        {
            IdentityUserClaim identityUserClaim = new IdentityUserClaim { ClaimType = claim.Type, ClaimValue = claim.Value };
            user.Claims.Add(identityUserClaim);
        }

        // Save the result
        var result = manager.Update(user);
        if (result.Succeeded)
        {
            store.Context.SaveChanges();
        }
    }

感谢您的帮助。

Answer 1

我最终找到了一个解决方案，但是，它在任何方面都不优雅。如果有人提出更好的解决方案，我仍然会很高兴看到它。

foreach (Claim claim in removed) {
    var claimCollection = store.Context.Entry(user).Collection(u => u.Claims).CurrentValue;
    var storedClaim = claimCollection.FirstOrDefault(c => c.ClaimType == claim.Type && c.ClaimValue == claim.Value && c.UserId == user.Id);
    if (storedClaim != null)
        store.Context.Entry(storedClaim).State = EntityState.Deleted;
}