在mvc中经常会使用到下拉列表，以下以两种方式来实现，一种是以 @Html.DropDownList 扩展方法，一种是以 <select><option></option></select> 这样的 html 代码和 HashTable来实现
1. @Html.DropDownList 扩展方法
View 代码：
@if (ViewData["listCategory"] != null) { @Html.DropDownList("listcategory", ViewData["listCategory"] as IEnumerable<SelectListItem>, "---请选择类型---") }
Control 代码：
ViewData["listCategory"] = cardCategory.GetAll();
public List<Sns.Management.Model.CardCategory> GetAll() { StringBuilder strSql = new StringBuilder(); strSql.Append("select "); strSql.Append(" id,category_name"); strSql.Append(" from pro_card_category"); strSql.Append(" order by sort asc"); DataSet ds = DbHelperMySQL.Query(strSql.ToString()); System.Collections.Hashtable hashtable = new System.Collections.Hashtable(); List<Sns.Management.Model.CardCategory> mylist = new List<Model.CardCategory>(); if (ds.Tables[0].Rows.Count > 0) { foreach (DataRow row in ds.Tables[0].Rows) { Sns.Management.Model.CardCategory model = new Model.CardCategory(); model.Id = row[0].ToString(); model.CategoryName = row[1].ToString(); mylist.Add(model); } } return mylist; }
2. 使用 html 标签 + HashTable
View 代码：
<select style="width:130px;" id="CategoryId" name="CategoryId"> <option value="0">请选择分类名称</option> @if (ViewData["listCategory"] != null) { System.Collections.Hashtable myhashtable = ViewData["listCategory"] as System.Collections.Hashtable; foreach (System.Collections.DictionaryEntry item in myhashtable) { <option value="@item.Key">@item.Value</option> } } </select>
Control 代码：
ViewData["listCategory"] = skinCategory.GetAll();
/// <summary> /// hashtable key: id的值， value: 分类名称 /// </summary> /// <returns></returns> public System.Collections.Hashtable GetAll() { StringBuilder strSql = new StringBuilder(); strSql.Append("select "); strSql.Append(" id,category_name"); strSql.Append(" from pro_skin_category"); strSql.Append(" order by sort asc"); DataSet ds = DbHelperMySQL.Query(strSql.ToString()); System.Collections.Hashtable hashtable = new System.Collections.Hashtable(); if (ds.Tables[0].Rows.Count > 0) { foreach (DataRow row in ds.Tables[0].Rows) { hashtable.Add(row[0].ToString(), row[1].ToString()); } } return hashtable; }
原文：http://www.cnblogs.com/wisdo/p/4357621.html
