LIOT/EMIS.Web/Controls/MinOrEqualDropDownListExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Linq.Expressions;
using Bowin.Web.Controls.Mvc;

namespace EMIS.Web.Controls
{
    public static class MinOrEqualDropDownListExtensions
    {
        public static MvcHtmlString MinOrEqualDropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper,
            Expression<Func<TModel, TProperty>> expression,
            DropdownListOptions dropdownListOptions = null,
            System.Collections.Generic.IDictionary<string, string> htmlAttributes = null)
        {
            ModelMetadata modelMetadata = ModelMetadata.FromLambdaExpression<TModel, TProperty>(expression, htmlHelper.ViewData);
            string fullHtmlFieldName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(ExpressionHelper.GetExpressionText(expression));

            //MVC验证支持
            var validateAttributes = htmlHelper.GetUnobtrusiveValidationAttributes(fullHtmlFieldName, modelMetadata);
            if (htmlAttributes == null)
            {
                htmlAttributes = new Dictionary<string, string>();
            }
            validateAttributes.ToList().ForEach(x => htmlAttributes.Add(x.Key, x.Value.ToString()));
            if (dropdownListOptions == null)
                dropdownListOptions = new DropdownListOptions();

            dropdownListOptions.ItemList = new List<DropdownListItem> 
            {
                new DropdownListItem { Text = "<", Value = "<" },
                new DropdownListItem { Text = "<=", Value = "<=" }
            };

            if (string.IsNullOrEmpty(dropdownListOptions.ID))
            {
                dropdownListOptions.ID = fullHtmlFieldName;
            }
            dropdownListOptions.Name = fullHtmlFieldName;
            dropdownListOptions.SelectedValue = (modelMetadata.Model ?? "<");

            return htmlHelper.DropdownList(dropdownListOptions, htmlAttributes);
        }
    }
}