MVC模型绑定

视图：

 1 @model RegisterViewModel
 2 @{
 3     ViewData["Title"] = "Register";
 4 }
 5 
 6 <h2>@ViewData["Title"]</h2>
 7 
 8 <div class="row">
 9     <div class="col-md-4">
10         <form asp-route-returnUrl="@ViewData["ReturnUrl"]" method="post">
11             <h4>Create a new account.</h4>
12             <hr />
13             <div asp-validation-summary="All" class="text-danger"></div>
14             <div class="form-group">
15                 <label asp-for="Email"></label>
16                 <input asp-for="Email" class="form-control" />
17                 <span asp-validation-for="Email" class="text-danger"></span>
18             </div>
19             <div class="form-group">
20                 <label asp-for="Password"></label>
21                 <input asp-for="Password" class="form-control" />
22                 <span asp-validation-for="Password" class="text-danger"></span>
23             </div>
24             <div class="form-group">
25                 <label asp-for="ConfirmPassword"></label>
26                 <input asp-for="ConfirmPassword" class="form-control" />
27                 <span asp-validation-for="ConfirmPassword" class="text-danger"></span>
28             </div>
29             <button type="submit" class="btn btn-default">Register</button>
30         </form>
31     </div>
32 </div>
33 
34 @section Scripts {
35     @await Html.PartialAsync("_ValidationScriptsPartial")
36 }

View Code

对应的控制器操作：

 1   [HttpPost]
 2         [AllowAnonymous]
 3         [ValidateAntiForgeryToken]
 4         public async Task<IActionResult> Register(RegisterViewModel model /*隐式模型绑定*/, string returnUrl = null)
 5         {
 6             var testModel = new TestRegisterModel();
 7             await TryUpdateModelAsync(testModel); //显示模型绑定，从请求的视图中更新当前模型对象
 8 
 9             ViewData["ReturnUrl"] = returnUrl;
10             if (ModelState.IsValid)
11             {
12                 var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
13                 var result = await _userManager.CreateAsync(user, model.Password);
14                 if (result.Succeeded)
15                 {
16                     _logger.LogInformation("User created a new account with password.");
17 
18                     var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
19                     var callbackUrl = Url.EmailConfirmationLink(user.Id, code, Request.Scheme);
20                     await _emailSender.SendEmailConfirmationAsync(model.Email, callbackUrl);
21 
22                     await _signInManager.SignInAsync(user, isPersistent: false);
23                     _logger.LogInformation("User created a new account with password.");
24                     return RedirectToLocal(returnUrl);
25                 }
26                 AddErrors(result);
27             }
28 
29             // If we got this far, something failed, redisplay form
30             return View(model);
31         }

View Code

隐式绑定参数RegisterViewModel的定义：

 1  public class RegisterViewModel
 2     {
 3         [Required]
 4         [EmailAddress]
 5         [Display(Name = "Email")]
 6         public string Email { get; set; }
 7 
 8         [Required]
 9         [StringLength(100, ErrorMessage = "The {0} must be at least {2} and at max {1} characters long.", MinimumLength = 6)]
10         [DataType(DataType.Password)]
11         [Display(Name = "Password")]
12         public string Password { get; set; }
13 
14         [DataType(DataType.Password)]
15         [Display(Name = "Confirm password")]
16         [Compare("Password", ErrorMessage = "The password and confirmation password do not match.")]
17         public string ConfirmPassword { get; set; }
18     }

View Code

显式绑定参数TestRegisterModel的定义：

1 public class TestRegisterModel
2     {
3         public string Sex { get; set; }
4         public string Email { get; set; }
5     }

View Code

当操作中有参数时，模型绑定会隐式的工作；如果操作中无参数，则可以使用UpdateModel()和TryUpdateModel()方法显式地调用模型绑定；
MVC模型绑定根据参数类型的属性（比如：ID，Title等等），会对应的在请求的视图中寻找对应的相同name属性值的控件的值，并将其传递给该参数的属性上；如果表单中不存在请求中的属性值，则参数的该属性将被自动赋值为空（NULL）；