C# 使用.SaveChanges（）保存电子邮件时出错；

当我将电子邮件留空并提交注册表时，它会将表单输入正确地保存到数据库中。但是，当我包括电子邮件前：testemail@gmail.com当db.SaveChanges时，产生验证错误；被称为

我收到的错误是：

EntityFramework.dll中发生类型为“System.Data.Entity.Validation.DbEntityValidationException”的异常，但未在用户代码中处理

其他信息：一个或多个实体的验证失败。有关详细信息，请参阅“EntityValidationErrors”属性

控制器：

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web;
using System.Web.Mvc;
using Mkq.Models;

namespace Mkq.Controllers
{
    public class TeacherController : Controller
    {
        private MkqDbEntities db = new MkqDbEntities();

    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public ActionResult Register([Bind(Include="teacher_id,subscription_id,teacher_fname,teacher_lname,username,password,email,teacher_credNumber,teacher_credST")] Teacher teacher)
    {
        teacher.subscription_id = 1;
        teacher.teacher_credNumber = null;
        teacher.teacher_credST = null;
        if (ModelState.IsValid)
        {
            db.Teachers.Add(teacher);
            db.SaveChanges();     //Error occurs when submitted
            return View();
        }

        // If we got this far, something failed, redisplay form
        return View(teacher);
    }

型号：

namespace Mkq.Models
{
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;

public partial class Teacher
{
    public Teacher()
    {
        this.Quiz_info = new HashSet<Quiz_info>();
        this.Students = new HashSet<Student>();
    }

    [DisplayName("Teacher ID")]
    public int teacher_id { get; set; }
    [DisplayName("Subscription ID")]
    public int subscription_id { get; set; }
    [DisplayName("First Name")]
    public string teacher_fname { get; set; }
    [DisplayName("Last Name")]
    public string teacher_lname { get; set; }
    [DisplayName("Username")]
    public string username { get; set; }
    [DisplayName("Password")]
    public string password { get; set; }
    [RegularExpression("^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$", ErrorMessage = "E-mail is not valid")]
    [DisplayName("Email")]
    public string email { get; set; }
    [DisplayName("Credential Number")]
    public string teacher_credNumber { get; set; }
    [DisplayName("Credential")]
    public string teacher_credST { get; set; }

    public virtual ICollection<Quiz_info> Quiz_info { get; set; }
    public virtual ICollection<Student> Students { get; set; }
    public virtual Subscription Subscription { get; set; }
}
}

视图：

---

如果您提供的值大于字段，则会发生这种情况；那是我经常听到的。但是，您可以通过捕获异常并检查其错误消息列表来获取所有错误：

catch (System.Data.Entity.Validation.DbEntityValidationException ex)
{
   foreach (var e in ex.EntityValidationErrors)
   {
      //check the ErrorMessage property
   }
}

在那里放一个断点，它会给出错误

try
{
  db.SaveChanges();
}

catch (DbEntityValidationException ex)
            {
                foreach (var entityValidationErrors in ex.EntityValidationErrors)
                {
                    foreach (var validationError in entityValidationErrors.ValidationErrors)
                    {
                        Response.Write("Property: " + validationError.PropertyName + " Error: " + validationError.ErrorMessage);
                    }
                }
            } 

---

response.write中的代码将为您提供属性名称和详细的错误消息。当用户输入大于数据库中字段的大小时，就会发生这种情况

向我们显示您收到的错误的详细信息。如果没有这一点，它几乎可以是任何东西。只需在db.savechanges execution同时删除[RegularExpression^[…]时复制您得到的异常，它是否会保存电子邮件地址和@Html.ValidationMessageForm=>m.email？我添加了上述错误的详细信息，并添加了一个try-catch块，该块给了我：System.Data.Entity.Validation.DbEntityValidationResultI已编辑了您的标题。请看，如果一致意见是否定的，则不应该。我添加了这段代码，它给了我：System.Data.Entity.Validation.DbEntityValida结果

try
{
  db.SaveChanges();
}

catch (DbEntityValidationException ex)
            {
                foreach (var entityValidationErrors in ex.EntityValidationErrors)
                {
                    foreach (var validationError in entityValidationErrors.ValidationErrors)
                    {
                        Response.Write("Property: " + validationError.PropertyName + " Error: " + validationError.ErrorMessage);
                    }
                }
            }