ModelState.AddModelError为什么没有ModelState.AddModelSuccess？

Question

ModelState是一个字典对象，它包含模型和模型构建验证的状态。

ModelState.AddModelError("MyKey", "My Error Message");   

AddModelError()，它将指定的错误消息添加到与指定键(MyKey)链接的模型状态字典的错误集合中。

为什么没有ModelState.AddModelSucces("MyKey", "My Error Message")？有人能告诉我如何在视图中显示成功信息吗？

ModelState.AddModelSucces("MyKey", "My Error Message") ???

Answer 1

您可以按照与Html.ValidationMessageFor相同的行创建helper扩展方法。

下面是一个例子，说明我很快就做了些什么，但是你可以进一步扩展它。看看http://aspnetwebstack.codeplex.com/SourceControl/latest#src/System.Web.Mvc/Html/ValidationExtensions.cs，了解更多的想法。

这将输出一个带有css类span标记的field-validation-valid。

<span class="field-validation-valid">My success message</span>

视图

@Html.ValidationSuccessMessageFor(m => m.MyProperty, "My success message")

可拓方法

public static MvcHtmlString ValidationSuccessMessageFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression)
{
    return ValidationSuccessMessageFor(htmlHelper, expression, null, new RouteValueDictionary());
}

public static MvcHtmlString ValidationSuccessMessageFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string validationMessage)
{
    return ValidationSuccessMessageFor(htmlHelper, expression, validationMessage, new RouteValueDictionary());
}

public static MvcHtmlString ValidationSuccessMessageFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string validationMessage, object htmlAttributes)
{
    return ValidationSuccessMessageFor(htmlHelper, expression, validationMessage, HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes));
}

public static MvcHtmlString ValidationSuccessMessageFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string validationMessage, IDictionary<string, object> htmlAttributes)
{
    return ValidationMessageHelper(htmlHelper, ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData), ExpressionHelper.GetExpressionText(expression), validationMessage, htmlAttributes);
}

private static MvcHtmlString ValidationMessageHelper(this HtmlHelper htmlHelper, ModelMetadata modelMetadata, string expression, string validationMessage, IDictionary<string, object> htmlAttributes)
{
    var modelName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(expression);
        FormContext formContext = htmlHelper.ViewContext.ClientValidationEnabled ? htmlHelper.ViewContext.FormContext : null;

    if (!htmlHelper.ViewData.ModelState.ContainsKey(modelName) && formContext == null)
    {
        return null;
    }

    var modelState = htmlHelper.ViewData.ModelState[modelName];

    if (modelState == null || (modelState != null && (modelState.Errors == null || modelState.Errors.Count > 0)))
    {
        return null;
    }

    var builder = new TagBuilder("span");
    builder.MergeAttributes(htmlAttributes);
    builder.AddCssClass(HtmlHelper.ValidationMessageValidCssClassName);

    if (!String.IsNullOrEmpty(validationMessage))
    {
        builder.SetInnerText(validationMessage);
    }

    return MvcHtmlString.Create(builder.ToString(TagRenderMode.Normal));
}