ASP. NET MVC5 Verification Series-server verification, asp. netmvc5

ASP. NET MVC5 Verification Series-server verification, asp. netmvc5

In this article, I will talk about using the data annotation API for server-side verification. ASP. net mvc Framework verifies all data transmitted to the controller during execution. If the verification fails, it fills in the error message to the ModelState object and passes the object to the Controller, then, the method in the Controller determines whether the verification fails or passes Based on the Modelstate status.

Here, I will use two methods to verify the validity of Data. One is to manually add an error message to the ModelState object, and the other is to use the Data Annotation [Data Annotation] API,.

Let's take a look at the manual verification method:

Create a blank MVC project: Add a Student object:

using System;using System.Collections.Generic;using System.Linq;using System.Web;namespace Server_Side_Validation_IN_MVC.Models{ public class Student {  public string Name { get; set; }  public string Email { get; set; } }}

Then add a Student controller:

Using Server_Side_Validation_IN_MVC.Models; using System. collections. generic; using System. linq; using System. text. regularExpressions; using System. web; using System. web. mvc; namespace Server_Side_Validation_IN_MVC.Controllers {public class StudentController: Controller {// GET: Student public ActionResult Index () {return View ();} [HttpPost] public ActionResult Index (Student model) {// server Server verification, Method 1: manually add an error message to the ModelState object // if the Name is empty if (string. isNullOrEmpty (model. name) {ModelState. addModelError ("Name", "Name is required");} // if the Email is empty if (string. isNullOrEmpty (model. email) {ModelState. addModelError ("Email", "Email is required");} else {string emailRegex = @ "^ ([a-zA-Z0-9 _ \-\.] +) @ (\ [0-9] {1, 3} "+ @"\. [0-9] {1, 3 }\. [0-9] {1, 3 }\.) | ([a-zA-Z0-9 \-] + \ "+ @".) +) ([a-zA-Z] {2, 4} | [0-9] {1, 3}) (\]?) $ "; Regex re = new Regex (emailRegex); // when the Email is not empty, but the format is invalid if (! Re. isMatch (model. email) {ModelState. addModelError ("Email", "Email is not valid") ;}// entity verification passes if (ModelState. isValid) {ViewBag. name = model. name; ViewBag. email = model. email;} return View (model );}}}

Create an Index View:

@ Model Server_Side_Validation_IN_MVC.Models.Student @ {Layout = null;} <! DOCTYPE html> 
Then, modify the default route:
public static void RegisterRoutes(RouteCollection routes)  {   routes.IgnoreRoute("{resource}.axd/{*pathInfo}");   routes.MapRoute(    name: "Default",    url: "{controller}/{action}/{id}",    defaults: new { controller = "Student", action = "Index", id = UrlParameter.Optional }   );  }
After running, an error is reported. After finding the cause, I modified the view code:

After running,

Next, verify that the Name is not empty and the Email enters invalid data format:

Finally, verify that valid data is entered:

Now let's take a look at the second method, using data annotation for server Verification:
Create a new class: avoid confusion,
Using System; using System. collections. generic; using System. componentModel. dataAnnotations; using System. linq; using System. web; namespace Server_Side_Validation_IN_MVC.Models {public class StudentServer {[Required (ErrorMessage = "Name is Required")] public string Name {get; set ;} [Required (ErrorMessage = "Email Required")] [EmailAddress (ErrorMessage = "Incorrect Email format")] public string Email {get; set ;}}}
Create two methods in the controller:
 public ActionResult SeverSideIndex()  {   return View();  }  [HttpPost]  public ActionResult SeverSideIndex(StudentServer model)  {   if (ModelState.IsValid)   {    ViewBag.Name = model.Name;    ViewBag.Email = model.Email;   }   return View();  }
View:
@model Server_Side_Validation_IN_MVC.Models.StudentServer@{ Layout = null;}@if (ViewData.ModelState.IsValid){ if (ViewBag.Name != null) {  <b>  Name:@ViewBag.Name<br />  Email:@ViewBag.Email </b> }}<!DOCTYPE html>



First, verify that all values are empty:

Name is not empty, Email is empty

Name is not blank. Invalid format data is entered by Email

Both of them enter valid data:

Well, the above is the server verification in MVC. We generally use the second method for verification. That is, data annotation.
The above is all the content of this article. I hope it will be helpful for your learning and support for helping customers.