获取操作的绝对值 URL（不在视图中）- NullReferenceException

Question

我搜索了很多这个问题，他们似乎都有相同的答案，而且似乎属于由视图而不是控制器调用。

我已尝试实现答案，但我在这部分得到 NullReferenceException url.RequestContext.HttpContext.Request.Url.Scheme;

我已经引用了 System.Web.Mvc; 但我仍然无法调用 Url.Action。相反，我必须创建一个 UrlHelper 的新对象，然后调用 Action 方法。我不确定这是否是我的问题的原因。

我的代码如下：

    public static class EmailHelper
            {

             public static string AbsoluteAction(this UrlHelper url, string actionName, string controllerName, object routeValues = null)
                {
                    // Throws NullReferenceException
                    string scheme = url.RequestContext.HttpContext.Request.Url.Scheme;

                    return url.Action(actionName, controllerName, routeValues, scheme);
                }

             public static async Task SendReset(string emailAddress)
                {
                    MailDefinition md = new MailDefinition()
                    {
                        IsBodyHtml = true,
                        Subject = "Password Reset",
                        BodyFileName = "~/Templates/ResetConfirm.html",
                    };


                    UrlHelper helper = new UrlHelper();
                    string url = helper.AbsoluteAction("Login", "Account");

                    ListDictionary replacements = new ListDictionary();
                    replacements.Add("{{LoginUrl}}", url);

                    MailMessage msg = md.CreateMailMessage(emailAddress, replacements, new System.Web.UI.Control());
                    SmtpClient client = new SmtpClient();

                    await client.SendMailAsync(msg);
                }
            }

编辑

我正在从 AccountController 的 ResetPassword post 操作中调用 SendReset

    public async Task<ActionResult> ResetPassword(ResetPasswordViewModel model)
    {
        // some code here...


       var result = await UserManager.ResetPasswordAsync(user.Id, model.Code, model.Password);
       if (result.Succeeded)
            {
                // Email confirmation of password reset
                await EmailHelper.SendReset(model.Email);

                return RedirectToAction("ResetPasswordConfirmation", "Account");
            }

Answer 1

UrlHelper 属性 Url 也可以在控制器中访问，因此为您的方法提供该实例以访问 UrlHelper:

public async Task<ActionResult> ResetPassword(ResetPasswordViewModel model)
{
    // some code here...
    await EmailHelper.SendReset(Url, model.Email);
    //...
}


public static class EmailHelper
{
    public static async Task SendReset(UrlHelper urlHelper, string emailAddress)
    {
        //...
        string url = urlHelper.AbsoluteAction("Login", "Account");
    }
}

获取操作的绝对值 URL（不在视图中）- NullReferenceException

Get Absolute URL of an Action (not in view) - NullReferenceException

.net

c#

asp.net-mvc

url-routing