.Net Core Entity Framework 邮箱确认链接点击后EmailConfirmed未更新

代码问题出在两个核心环节：

• 构造邮件正文时对生成的回调链接callbackUrl做了多余的全量HTML编码，导致URL中的查询参数分隔符&被转义为&
• 邮件发送逻辑中直接将带HTML标签和转义字符的内容同时赋值给了纯文本和HTML两种邮件格式的内容，导致邮箱客户端解析链接时出错，服务器收到请求时无法正确识别code参数

方案1：直接修复编码错误（推荐） #

修改Register.cshtml.cs中构造邮件正文的代码，移除对callbackUrl的HtmlEncoder.Default.Encode调用：

// 原错误代码
// var mailBody = _loc.GetLocalizedString(CultureInfo.CurrentCulture.Name, "Please confirm your GatheringForGood account by <a href='{0}'>clicking here</a>.", HtmlEncoder.Default.Encode(callbackUrl));

// 替换为正确代码
var mailBody = _loc.GetLocalizedString(CultureInfo.CurrentCulture.Name, "Please confirm your GatheringForGood account by <a href='{0}'>clicking here</a>.", callbackUrl);

Url.Page生成的回调链接本身已经完成了URL编码，放在用引号包裹的href属性中无需额外做HTML全量编码。

方案2：优化邮件发送逻辑（可选，兼容纯文本邮件用户） #

修改EmailSender.cs的发送逻辑，分开生成纯文本和HTML版本的邮件内容，避免转义字符出现在纯文本链接中：

// 先在Register.cshtml.cs中构造两个版本的内容
var htmlBody = _loc.GetLocalizedString(CultureInfo.CurrentCulture.Name, "Please confirm your GatheringForGood account by <a href='{0}'>clicking here</a>.", callbackUrl);
var plainTextBody = _loc.GetLocalizedString(CultureInfo.CurrentCulture.Name, "Please confirm your GatheringForGood account by opening this link: {0}", callbackUrl);
// 发送时传入两个版本的内容
await _emailSender.SendEmailAsync(Input.Email, mailHeader, plainTextBody, htmlBody);

// 对应修改EmailSender的方法
public Task SendEmailAsync(string email, string subject, string plainTextMessage, string htmlMessage)
{
    return Execute(Options.SendGridKey, subject, plainTextMessage, htmlMessage, email);
}

public Task Execute(string apiKey, string subject, string plainTextMessage, string htmlMessage, string email)
{
    var client = new SendGridClient(apiKey);
    var msg = new SendGridMessage()
    {
        From = new EmailAddress("info@myemail.com", Options.SendGridUser),
        Subject = subject,
        PlainTextContent = plainTextMessage,
        HtmlContent = htmlMessage
    };
    msg.AddTo(new EmailAddress(email));
    msg.SetClickTracking(false, false);
    return client.SendEmailAsync(msg);
}

临时兼容方案（如果无法立即修改上游逻辑） #

如果暂时无法修改邮件生成逻辑，可以在ConfirmEmail.cshtml.cs的OnGetAsync方法最开头增加手动参数兼容逻辑：

public async Task<IActionResult> OnGetAsync(string userId, string code)
{
    // 兼容被错误转义的参数
    if (string.IsNullOrEmpty(code) && Request.Query.ContainsKey("amp;code"))
    {
        code = Request.Query["amp;code"];
    }
    
    // 原有逻辑不变
    if (userId == null || code == null)
    {
        return RedirectToPage("/Index", new { culture });
    }
    // ... 其余原有代码保持不变
}

内容的提问来源于stack exchange，提问作者DMur