转载请注明出处：http://www.cnblogs.com/zhiyong-ITNote/
官方网站：https://docs.microsoft.com/zh-cn/aspnet/core/mvc/models/validation?view=aspnetcore-2.1
首先派生自ValidationAttribute以及IClientModelValidator：
代码语言：javascript复制public class ClassicMovieAttribute : ValidationAttribute, IClientModelValidator
{
private int _year;
public ClassicMovieAttribute(int Year)
{
_year = Year;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
Movie movie = (Movie)validationContext.ObjectInstance;
if (movie.Genre == Genre.Classic && movie.ReleaseDate.Year > _year)
{
return new ValidationResult(GetErrorMessage());
}
return ValidationResult.Success;
}
public void AddValidation(ClientModelValidationContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
MergeAttribute(context.Attributes, "data-val", "true");
MergeAttribute(context.Attributes, "data-val-classicmovie", GetErrorMessage());
var year = _year.ToString(CultureInfo.InvariantCulture);
MergeAttribute(context.Attributes, "data-val-classicmovie-year", year);
}
private bool MergeAttribute(IDictionary<string, string> attributes, string key, string value)
{
if (attributes.ContainsKey(key))
{
return false;
}
attributes.Add(key, value);
return true;
}
private string GetErrorMessage()
{
return $"Classic movies must have a release year earlier than {_year}.";
}
}创建两个类：
代码语言：javascript复制创建两个类：
public class Movie
{
public int Id { get; set; }
[Required]
[StringLength(100)]
public string Title { get; set; }
[ClassicMovie(1960)]
[DataType(DataType.Date)]
public DateTime ReleaseDate { get; set; }
[Required]
[StringLength(1000)]
public string Description { get; set; }
[Range(0, 999.99)]
public decimal Price { get; set; }
[Required]
public Genre Genre { get; set; }
public bool Preorder { get; set; }
}
public enum Genre
{
Classic,
PostClassic,
Modern,
PostModern,
Contemporary,
}视图方面：
代码语言：javascript复制<form asp-action="Create">
<div class="form-horizontal">
<h4>Movie</h4>
<hr />
<div asp-validation-summary="ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="Title" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="Title" class="form-control" />
<span asp-validation-for="Title" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<label asp-for="ReleaseDate" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="ReleaseDate" class="form-control" />
<span asp-validation-for="ReleaseDate" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<label asp-for="Description" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="Description" class="form-control" />
<span asp-validation-for="Description" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<label asp-for="Price" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="Price" class="form-control" />
<span asp-validation-for="Price" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<label asp-for="Genre" class="col-md-2 control-label"></label>
<div class="col-md-10">
<select asp-for="Genre" asp-items="@(Html.GetEnumSelectList<Genre>())" class="form-control"></select>
<span asp-validation-for="Genre" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<div class="checkbox">
<input asp-for="Preorder" />
<label asp-for="Preorder"></label>
</div>
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
</form>
@section Scripts {
@{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
<script type="text/javascript">
$(function () {
$.validator.addMethod('classicmovie',
function (value, element, params) {
// Get element value. Classic genre has value '0'.
var genre = $(params[0]).val(),
year = params[1],
date = new Date(value);
if (genre && genre.length > 0 && genre[0] === '0') {
// Since this is a classic movie, invalid if release date is after given year.
return date.getFullYear() <= year;
}
return true;
});
$.validator.unobtrusive.adapters.add('classicmovie',
['year'],
function (options) {
var element = $(options.form).find('select#Genre')[0];
options.rules['classicmovie'] = [element, parseInt(options.params['year'])];
options.messages['classicmovie'] = options.message;
});
});
</script>
}
然后创建一个Action:
public IActionResult Index(Movie movie)
{
if(ModelState.isValid)
{
return Content("dsadas");
}
return View();
}然后创建一个Action:
代码语言：javascript复制public IActionResult Index(Movie movie)
{
if(ModelState.isValid)
{
return Content("dsadas");
}
return View();
}我们可以在qq浏览器中的查看页面源代码，会给我们生成：
代码语言：javascript复制<input class="form-control" type="datetime"
data-val="true"
data-val-classicmovie="Classic movies must have a release year earlier than 1960."
data-val-classicmovie-year="1960"
data-val-required="The ReleaseDate field is required."
id="ReleaseDate" name="ReleaseDate" value="" />也就是说，浏览器已经给我们解析好了，这样我们就可以一次比较，前后端验证。当然我们也可以使用bootstrapValidator验证。
