为什么我的表单验证器不验证我的表单？

Question

So I'm trying to create a basic register page where the user needs to fill out all the fields in order to proceed. But the issue I'm facing is that when I click "Create" to finish the process, it just refreshes the page and there are no errors shown, even if I don't fill out any of the fields.

This is the Controller

public IActionResult Register()
{
    return View();
}

This is the form

<form>
    <div asp-validation-summary="All" class="text-danger"></div>
    <div class="form-group">
        <label asp-for="Username" class="control-label"></label>
        <input asp-for="Username" class="form-control" />
        <span asp-validation-for="Username" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="Password" class="control-label"></label>
        <input asp-for="Password" class="form-control" />
        <span asp-validation-for="Password" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="ConfirmPassword" class="control-label"></label>
        <input asp-for="ConfirmPassword" class="form-control" />
        <span asp-validation-for="ConfirmPassword" class="text-danger"></span>
    </div>
    <div class="form-group form-check">
        <label class="form-check-label">
            <input class="form-check-input" asp-for="Agree" /> @Html.DisplayNameFor(model => model.Agree)
        </label>
    </div>
    <div class="form-group">
        <input type="submit" value="Create" class="btn btn-primary" />
    </div>
</form>

And obviously the model

public class RegisterAccountModel
{
    [Required(ErrorMessage = "This field is required.")]
    [StringLength(60, MinimumLength = 3)]
    [DataType(DataType.Text)]
    public string Username { get; set; }

    [Required(ErrorMessage = "This field is required.")]
    [DataType(DataType.Password)]
    public string Password { get; set; }

    [Required(ErrorMessage = "This field is required.")]
    [DataType(DataType.Password)]
    [Compare("Password", ErrorMessage = "The Password and Confirm password must match.")]
    public string ConfirmPassword { get; set; }

    [Required(ErrorMessage = "This field is required.")]
    //[DataType(DataType.Password)]
    public bool Agree { get; set; }
}

Why is the page just refreshing without showing any errors when I click the "Create" button?

Answer 1

You need to use the model state valid to start the valuation

public IActionResult Register()
{

    if (ModelState.IsValid) { //checking model state
                // send to the original action 
                return RedirectToAction("Index");
    }
    return View();
}