愛上(shang)MVC~為(wei)CheckBoxFor和RadioButtonFor加個擴展方(fang)法吧（希望MVC5把這方(fang)法收納——呵(he)呵(he)）
說在前
我都是(shi)喜歡把問題復雜化，還(huan)有總是(shi)喜歡把問題簡單(dan)化，偷懶化，這也需就是(shi)一個程序員的追求吧，呵呵。
我(wo)(wo)不(bu)太喜歡重(zhong)復(fu)的(de)(de)(de)(de)(de)東西，當你看到頁面上有一個(ge)以上相同的(de)(de)(de)(de)(de)代碼(ma)(ma)(ma)時，那可以說(shuo)(shuo)，你的(de)(de)(de)(de)(de)代碼(ma)(ma)(ma)有重(zhong)構(gou)的(de)(de)(de)(de)(de)余地，應該(gai)考慮重(zhong)構(gou)了(le)，今天看了(le)以前同事(shi)的(de)(de)(de)(de)(de)博客，寫了(le)關于DropDownList的(de)(de)(de)(de)(de)用法(fa)(fa)，如(ru)何將集(ji)合數據(ju)綁定到下拉列表框(kuang)上，講的(de)(de)(de)(de)(de)不(bu)錯，但最后(hou)在說(shuo)(shuo)checkbox和radiobutton時，我(wo)(wo)感覺有點(dian)重(zhong)復(fu)了(le)，我(wo)(wo)說(shuo)(shuo)的(de)(de)(de)(de)(de)是代碼(ma)(ma)(ma)重(zhong)復(fu)了(le)，還有就(jiu)(jiu)是代碼(ma)(ma)(ma)復(fu)雜(za)化(hua)了(le)，就(jiu)(jiu)是說(shuo)(shuo)，我(wo)(wo)再使用集(ji)合來產(chan)生(sheng)checkbox和radiobutton時，代碼(ma)(ma)(ma)有些復(fu)雜(za)了(le)，這不(bu)是我(wo)(wo)們希(xi)望看到的(de)(de)(de)(de)(de)，所(suo)以，我(wo)(wo)覺得(de)有必要(yao)把它重(zhong)構(gou)一下，為mvc加(jia)兩(liang)個(ge)擴展方(fang)法(fa)(fa)吧，呵呵。
做在后
DropDownListFor的方法簽名做的不(bu)錯，很面向對象，很簡潔，但不(bu)知(zhi)不(bu)何，checkbox和radiobutton確沒有這樣的重(zhong)載，呵呵
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList); public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, IDictionary<string, object> htmlAttributes); public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, object htmlAttributes); public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel); public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel, IDictionary<string, object> htmlAttributes); public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string optionLabel, object htmlAttributes);
對于checkbox和radiobutton它們只(zhi)有簡單的(de)幾個重載，沒有對集合(he)的(de)支(zhi)持，所(suo)以，我的(de)這次(ci)代碼擴展，主要是針(zhen)對集合(he)來說的(de)，看(kan)方法簽名：
下面看一(yi)(yi)下原代碼，它直接寫在(zai)了System.Web.Mvc命名(ming)空間下，這更說明我是對微軟MVC的一(yi)(yi)個擴展，希望(wang)MVC5出來(lai)時，可以把這些都(dou)集成進去(qu)，呵(he)呵(he)
#region 單選框和復選框的擴展 /// <summary> /// 復選(xuan)框,selValue為選(xuan)中項 /// </summary> /// <param name="htmlHelper"></param> /// <param name="name"></param> /// <param name="selectList"></param> /// <param name="selValue"></param> /// <returns></returns> public static MvcHtmlString CheckBox(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList, IEnumerable<string> selValue) { return CheckBoxAndRadioFor<object, string>(name, selectList, false, selValue); } public static MvcHtmlString CheckBox(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList, string selValue) { return CheckBox(htmlHelper, name, selectList, new List<string> { selValue }); } /// <summary> /// 復(fu)選框 /// </summary> /// <param name="htmlHelper"></param> /// <param name="name"></param> /// <param name="selectList"></param> /// <returns></returns> public static MvcHtmlString CheckBoxFor(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList) { return CheckBox(htmlHelper, name, selectList, new List<string>()); } /// <summary> /// 根據(ju)列表輸出checkbox /// </summary> /// <typeparam name="TModel"></typeparam> /// <typeparam name="TProperty"></typeparam> /// <param name="htmlHelper"></param> /// <param name="expression"></param> /// <param name="selectList"></param> /// <returns></returns> public static MvcHtmlString CheckBoxFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList) { return CheckBoxFor(htmlHelper, expression, selectList, null); } /// <summary> /// 根據列表輸(shu)出checkbox,selValue為(wei)默認選中的項 /// </summary> /// <typeparam name="TModel"></typeparam> /// <typeparam name="TProperty"></typeparam> /// <param name="htmlHelper"></param> /// <param name="expression"></param> /// <param name="selectList"></param> /// <param name="selValue"></param> /// <returns></returns> public static MvcHtmlString CheckBoxFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string selValue) { string name = ExpressionHelper.GetExpressionText(expression); return CheckBoxAndRadioFor<TModel, TProperty>(name, selectList, false, new List<string> { selValue }); } /// <summary> /// 輸出單選(xuan)框和復選(xuan)框 /// </summary> /// <typeparam name="TModel"></typeparam> /// <;typeparam name="TProperty"></typeparam> /// <param name="expression"></param> /// <param name="selectList"></param> /// <param name="isRadio"></param> /// <param name="selValue"></param> /// <returns></returns> static MvcHtmlString CheckBoxAndRadioFor<TModel, TProperty>( string name, IEnumerable<SelectListItem> selectList, bool isRadio, IEnumerable<string> selValue) { StringBuilder str = new StringBuilder(); int c = 0; string check, activeClass; string type = isRadio ? "Radio" : "checkbox"; foreach (var item in selectList) { c++; if (selValue != null && selValue.Contains(item.Value)) { check = "checked='checked'"; activeClass = "style=color:red"; } else { check = string.Empty; activeClass = string.Empty; } str.AppendFormat("<span><input type='{3}' value='{0}' name={1} id={1}{2} " + check + "/>", item.Value, name, c, type); str.AppendFormat("<label for='{0}{1}' {3}>{2}</lable></span>", name, c, item.Text, activeClass); } return MvcHtmlString.Create(str.ToString()); } public static MvcHtmlString RadioButton(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList, IEnumerable<string> selValue) { return CheckBoxAndRadioFor<object, string>(name, selectList, true, selValue); } /// <summary> /// 單選按(an)鈕組，seletList為選中(zhong)項 /// </summary> /// <param name="htmlHelper"></param> /// <param name="name"></param> /// <param name="selectList"></param> /// <param name="selValue"></param> /// <returns></returns> public static MvcHtmlString RadioButton(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList, string selValue) { return RadioButton(htmlHelper, name, selectList, new List<string> { selValue }); } /// <summary> /// 單選按(an)鈕組 /// </summary> /// <param name="htmlHelper"></param> /// <param name="name"></param> /// <param name="selectList"></param> /// <returns></returns> public static MvcHtmlString RadioButton(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItem> selectList) { return RadioButton(htmlHelper, name, selectList, new List<string>()); } /// <summary> /// 根(gen)據(ju)列表輸出radiobutton /// </summary> /// <typeparam name="TModel"></typeparam> /// <typeparam name="TProperty"></typeparam> /// <param name="htmlHelper"></param> /// <param name="expression"></param> /// <param name="selectList"></param> /// <returns></returns> public static MvcHtmlString RadioButtonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList) { return RadioButtonFor(htmlHelper, expression, selectList, new List<string>()); } public static MvcHtmlString RadioButtonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, IEnumerable<string> selValue) { string name = ExpressionHelper.GetExpressionText(expression); return CheckBoxAndRadioFor<TModel, TProperty>(name, selectList, true, selValue); } /// <summary> /// 根據(ju)列表輸出radiobutton,selValue為(wei)默認選中(zhong)的項 /// </summary> /// <typeparam name="TModel"></typeparam> /// <typeparam name="TProperty"></typeparam> /// <param name="htmlHelper"></param> /// <param name="expression"></param> /// <param name="selectList"></param> /// <param name="selValue"></param> /// <returns></returns> public static MvcHtmlString RadioButtonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> selectList, string selValue) { return RadioButtonFor(htmlHelper, expression, selectList, new List<string> { selValue }); } #endregion
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