[转]ASP.NET MVC HtmlHelper扩展之Calendar日期时间选择

本文转自：http://blog.bossma.cn/asp_net_mvc/asp-net-mvc-htmlhelper-calendar-datetime-select/

这里我们扩展HtmlHelper，就像它包含在ASP.NET MVC中一样，扩展方法使我们能为已有的类添加方法。这里使用了一个日期时间选择控件：My97DatePicker，需要添加到网站中，并在页面中引用。

先看看是怎么扩展的：

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using System; using System.Collections.Generic; using System.Runtime.CompilerServices; using System.Linq.Expressions;   namespace System.Web.Mvc {     /// <summary>     /// Extended the HtmlHelper for Calendar     /// </summary>     public static class CalendarExtensions     {         private static string defaultFormat = "yyyy-MM-dd";           /// <summary>         /// 使用特定的名称生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="name">控件名称</param>         /// <returns>Html文本</returns>         public static string Calendar(this HtmlHelper helper, string name)         {             return Calendar(helper, name, defaultFormat);         }           /// <summary>         /// 使用特定的名称生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="name">控件名称</param>         /// <param name="format">显示格式</param>         /// <returns>Html文本</returns>         public static string Calendar(this HtmlHelper helper, string name, string format)         {             return GenerateHtml(name, null, format);         }           /// <summary>         /// 使用特定的名称和初始值生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="name">控件名称</param>         /// <param name="date">要显示的日期时间</param>         /// <returns>Html文本</returns>         public static string Calendar(this HtmlHelper helper, string name, DateTime date)         {             return Calendar(helper, name, date, defaultFormat);         }           /// <summary>         /// 使用特定的名称和初始值生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="name">控件名称</param>         /// <param name="date">要显示的日期时间</param>         /// <param name="format">显示格式</param>         /// <returns>Html文本</returns>         public static string Calendar(this HtmlHelper helper, string name, DateTime date, string format)         {             return GenerateHtml(name, date, format);         }           /// <summary>         /// 通过lambda表达式生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>         /// <returns>Html文本</returns>         public static string CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)         {             return CalendarFor(helper, expression, defaultFormat);         }           /// <summary>         /// 通过lambda表达式生成控件         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>         /// <param name="format">显示格式</param>         /// <returns>Html文本</returns>         public static string CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)         {             string name = ExpressionHelper.GetExpressionText(expression);             DateTime value;               object data = ModelMetadata.FromLambdaExpression<TModel, TProperty>(expression, helper.ViewData).Model;             if (data != null && DateTime.TryParse(data.ToString(), out value))             {                 return GenerateHtml(name, value, format);             }             else             {                 return GenerateHtml(name, null, format);             }         }           /// <summary>         /// 通过lambda表达式获取要显示的日期时间         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>         /// <param name="format">显示格式</param>         /// <returns>Html文本</returns>         public static string CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)         {             string name = ExpressionHelper.GetExpressionText(expression);             DateTime value;               object data = ModelMetadata.FromLambdaExpression<TModel, TProperty>(expression, helper.ViewData).Model;             if (data != null && DateTime.TryParse(data.ToString(), out value))             {                 return value.ToString(format);             }             else             {                 return string.Empty;             }         }           /// <summary>         /// 通过lambda表达式获取要显示的日期时间         /// </summary>         /// <param name="helper">HtmlHelper对象</param>         /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>         /// <returns>Html文本</returns>         public static string CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)         {             return CalendarDisplayFor(helper, expression, defaultFormat);         }           /// <summary>         /// 生成输入框的Html         /// </summary>         /// <param name="name">calendar的名称</param>         /// <param name="date">calendar的值</param>         /// <returns>html文本</returns>         private static string GenerateHtml(string name, DateTime? date, string format)         {             if (date != null)             {                 return "<input type=\"text\" id=\"" + name + "\" name=\"" + name + "\" onfocus=\"WdatePicker({dateFmt:'" + format + "'})\" class=\"Wdate\" value=\"" + date.Value.ToString(format) + "\" />";             }             else             {                 return "<input type=\"text\" id=\"" + name + "\" name=\"" + name + "\" onfocus=\"WdatePicker({dateFmt:'" + format + "'})\" class=\"Wdate\" value=\"\" />";             }         }     } }

使用办法：

日期选择输入框： <%= Html.CalendarFor(model => model.PlanStartTime)%>

显示日期：<%= Html.CalendarDisplayFor(model => model.PlanStartTime)%>

日期时间选择输入框：<%= Html.CalendarFor(model => model.PlanStartTime, “yyyy-MM-dd HH:mm”)%>