2012年9月24日 星期一

ASP.NET MVC - 修改 CheckBoxList、增加 RadioButtonList


在今年初我有發表一篇有關於可以水平、垂直顯示的 CheckBoxList Extensions,其實這個 Html Helper Extensions 是沒有什麼問題,「ASP.NET MVC 擴充HtmlHelper 加入 CheckBoxList 功能 - 2」,前不久在看 DropDownList() 原始碼時想到,為什麼不直接使用既有的 SelectListItem 呢?實在是沒有必要另外去建立一個相同結構的 CheckBoxListInfo 類別,所以這次就做個小修改,捨棄原先的 CheckBoxListInfo 類別而改使用既有 SelectListItem 類別,而既然 CheckBoxList 都已經做出來了,那長得差不多的 RadioButtonList 也就動手做了出來,以下就是這兩個 Html Helper Extensions 的介紹。

 


基本使用:

先來看看 CheckBoxList 與 RadioButtonList 的執行結果,

image

CheckBoxList 與 RadioButtonList 都同樣的顯示了水平與垂直顯示的列表,水平列表是每個橫列都顯示兩個項目,垂直列表則都是顯示三個直行。

 

接下來看看 Controller Action() 方法的程式內容:

從資料庫取出產品分類的資料,然後建立 List<SelectListItem> 集合物件,接著再把 items 物件給放到 ViewBag 之中,等一下前端 View 設定時可以使用到。

image

 

View 的設定:

使用 Position.Horizontal 時,最後的數值參數是用來決定每個橫列要顯示多少個項目數量,使用 Position.Vertical 時,最後的數值參數則是用來決定要顯示多少直行數,

image

 

 

設定預設選項:

這邊設定預設選項的方式與設定下拉選單預選項目的方式是一樣的,將 SelectListItem 的 Selctedn 設定為 true 就可以,CheckBoxList 是可以設定多個項目為選擇狀態,至於 RadioButtonList 則是與 DropDownList 一樣為單選。

 

先看看 CheckBoxList 的內容,

Controller:

這裡是讓 CategoryID 為偶數的項目設定為與選項目

image

 

View:

View 這邊的設定並不需要去做任何的變動

image

 

執行結果:

image

 

RadioButtonList 的內容,

因為 RadioButtonList 跟 DropDownList 一樣是屬於單選的列表,所以如果是拿上面 Controller 的設定內容來使用的話,並不會有多個 RadioButton 被選取的情況發生,只有最後一個 Selected == true 的 SelectListItem 是會被選取的,

Controller:

image

View:

image

執行結果:

image

 

 

使用 SelectList

當然除了使用 IEnumerable<SelectListItem> 之外,也是一樣可以使用 SelectList 類別,在之前討論 DropDownList 基本設定的文章當中就已經有說過 SelectList 的父類別 MultiSelectList 就是繼承自 IEnumerable<SelectListItem>,所以當然可以使用 SelectList。

 

Controller:

image

View:

image

執行結果:

image

 


CheckBoxList & RadioButtonList 原始檔

這邊公布原始檔的程式內容,請各位自行做適當的修改後再加入到自己的 ASP.NET MVC 專案中,經過測試,於 ASP.NET MVC 3.0 與 ASP.NET MVC 4.0 的網站專案中都可以正常執行。

image

 

Position.cs

   1: using System;
   2: using System.Collections.Generic;
   3: using System.Linq;
   4: using System.Web;
   5:  
   6: namespace MvcApplication.Helpers
   7: {
   8:     public enum Position
   9:     {
  10:         Horizontal,
  11:         Vertical
  12:     }
  13: }

 

CheckBoxListExtensions.cs

image

   1: using System;
   2: using System.Collections.Generic;
   3: using System.Linq;
   4: using System.Text;
   5: using System.Web.Mvc;
   6: using System.Web.Routing;
   7:  
   8: namespace MvcApplication.Helpers
   9: {
  10:     public static class CheckBoxListExtensions
  11:     {
  12:         #region -- CheckBoxList (Horizontal) --
  13:         /// <summary>
  14:         /// CheckBoxList.
  15:         /// </summary>
  16:         /// <param name="htmlHelper">The HTML helper.</param>
  17:         /// <param name="name">The name.</param>
  18:         /// <param name="listInfo">SelectListItem.</param>
  19:         /// <returns></returns>
  20:         public static MvcHtmlString CheckBoxList(this HtmlHelper htmlHelper, 
  21:             string name, 
  22:             IEnumerable<SelectListItem> listInfo)
  23:         {
  24:             return htmlHelper.CheckBoxList(name, listInfo, (IDictionary<string, object>)null, 0);
  25:         }
  26:  
  27:         /// <summary>
  28:         /// CheckBoxList.
  29:         /// </summary>
  30:         /// <param name="htmlHelper">The HTML helper.</param>
  31:         /// <param name="name">The name.</param>
  32:         /// <param name="listInfo">SelectListItem.</param>
  33:         /// <param name="htmlAttributes">The HTML attributes.</param>
  34:         /// <returns></returns>
  35:         public static MvcHtmlString CheckBoxList(this HtmlHelper htmlHelper, 
  36:             string name, 
  37:             IEnumerable<SelectListItem> listInfo, 
  38:             object htmlAttributes)
  39:         {
  40:             return htmlHelper.CheckBoxList(name, listInfo, (IDictionary<string, object>)new RouteValueDictionary(htmlAttributes), 0);
  41:         }
  42:  
  43:         /// <summary>
  44:         /// CheckBoxList.
  45:         /// </summary>
  46:         /// <param name="htmlHelper">The HTML helper.</param>
  47:         /// <param name="name">The name.</param>
  48:         /// <param name="listInfo">The list info.</param>
  49:         /// <param name="htmlAttributes">The HTML attributes.</param>
  50:         /// <param name="number">每個Row的顯示個數.</param>
  51:         /// <returns></returns>
  52:         public static MvcHtmlString CheckBoxList(this HtmlHelper htmlHelper,
  53:             string name,
  54:             IEnumerable<SelectListItem> listInfo,
  55:             IDictionary<string, object> htmlAttributes,
  56:             int number)
  57:         {
  58:             if (String.IsNullOrEmpty(name))
  59:             {
  60:                 throw new ArgumentException("必須給這些CheckBoxList一個Tag Name", "name");
  61:             }
  62:             if (listInfo == null)
  63:             {
  64:                 throw new ArgumentNullException("listInfo", "必須要給List<SelectListItem> listInfo");
  65:             }
  66:             if (listInfo.Count() < 1)
  67:             {
  68:                 throw new ArgumentException("List<SelectListItem> listInfo 至少要有一組資料", "listInfo");
  69:             }
  70:  
  71:             StringBuilder sb = new StringBuilder();
  72:             int lineNumber = 0;
  73:  
  74:             foreach (SelectListItem info in listInfo)
  75:             {
  76:                 lineNumber++;
  77:  
  78:                 TagBuilder builder = new TagBuilder("input");
  79:                 if (info.Selected)
  80:                 {
  81:                     builder.MergeAttribute("checked", "checked");
  82:                 }
  83:                 builder.MergeAttributes<string, object>(htmlAttributes);
  84:                 builder.MergeAttribute("type", "checkbox");
  85:                 builder.MergeAttribute("value", info.Value);
  86:                 builder.MergeAttribute("name", name);
  87:                 sb.Append(builder.ToString(TagRenderMode.Normal));
  88:  
  89:                 TagBuilder labelBuilder = new TagBuilder("label");
  90:                 labelBuilder.MergeAttribute("for", name);
  91:                 labelBuilder.InnerHtml = info.Text;
  92:                 sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
  93:  
  94:                 if (number == 0 || (lineNumber % number == 0))
  95:                 {
  96:                     sb.Append("<br />");
  97:                 }
  98:             }
  99:             return MvcHtmlString.Create(sb.ToString());
 100:         }
 101:         #endregion
 102:  
 103:         #region -- CheckBoxListVertical --
 104:         /// <summary>
 105:         /// Checks the box list vertical.
 106:         /// </summary>
 107:         /// <param name="htmlHelper">The HTML helper.</param>
 108:         /// <param name="name">The name.</param>
 109:         /// <param name="listInfo">The list info.</param>
 110:         /// <param name="htmlAttributes">The HTML attributes.</param>
 111:         /// <param name="columnNumber">The column number.</param>
 112:         /// <returns></returns>
 113:         public static MvcHtmlString CheckBoxListVertical(this HtmlHelper htmlHelper,
 114:             string name,
 115:             IEnumerable<SelectListItem> listInfo,
 116:             IDictionary<string, object> htmlAttributes,
 117:             int columnNumber = 1)
 118:         {
 119:             if (String.IsNullOrEmpty(name))
 120:             {
 121:                 throw new ArgumentException("必須給這些CheckBoxList一個Tag Name", "name");
 122:             }
 123:             if (listInfo == null)
 124:             {
 125:                 throw new ArgumentNullException("listInfo", "必須要給List<CheckBoxListInfo> listInfo");
 126:             }
 127:             if (listInfo.Count() < 1)
 128:             {
 129:                 throw new ArgumentException("List<CheckBoxListInfo> listInfo 至少要有一組資料", "listInfo");
 130:             }
 131:  
 132:             int dataCount = listInfo.Count();
 133:  
 134:             // calculate number of rows
 135:             int rows = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(dataCount) / Convert.ToDecimal(columnNumber)));
 136:             if (dataCount <= columnNumber || dataCount - columnNumber == 1)
 137:             {
 138:                 rows = dataCount;
 139:             }
 140:  
 141:             TagBuilder wrapBuilder = new TagBuilder("div");
 142:             wrapBuilder.MergeAttribute("style", "float: left; light-height: 25px; padding-right: 5px;");
 143:  
 144:             string wrapStart = wrapBuilder.ToString(TagRenderMode.StartTag);
 145:             string wrapClose = string.Concat(wrapBuilder.ToString(TagRenderMode.EndTag), " <div style=\"clear:both;\"></div>");
 146:             string wrapBreak = string.Concat("</div>", wrapBuilder.ToString(TagRenderMode.StartTag));
 147:  
 148:             StringBuilder sb = new StringBuilder();
 149:             sb.Append(wrapStart);
 150:  
 151:             int lineNumber = 0;
 152:  
 153:             foreach (var info in listInfo)
 154:             {
 155:                 TagBuilder builder = new TagBuilder("input");
 156:                 if (info.Selected)
 157:                 {
 158:                     builder.MergeAttribute("checked", "checked");
 159:                 }
 160:                 builder.MergeAttributes<string, object>(htmlAttributes);
 161:                 builder.MergeAttribute("type", "checkbox");
 162:                 builder.MergeAttribute("value", info.Value);
 163:                 builder.MergeAttribute("name", name);
 164:                 sb.Append(builder.ToString(TagRenderMode.Normal));
 165:  
 166:                 TagBuilder labelBuilder = new TagBuilder("label");
 167:                 labelBuilder.MergeAttribute("for", name);
 168:                 labelBuilder.InnerHtml = info.Text;
 169:                 sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
 170:  
 171:                 lineNumber++;
 172:  
 173:                 if (lineNumber.Equals(rows))
 174:                 {
 175:                     sb.Append(wrapBreak);
 176:                     lineNumber = 0;
 177:                 }
 178:                 else
 179:                 {
 180:                     sb.Append("<br/>");
 181:                 }
 182:             }
 183:             sb.Append(wrapClose);
 184:             return MvcHtmlString.Create(sb.ToString());
 185:         }
 186:         #endregion
 187:  
 188:         #region -- CheckBoxList (Horizonal, Vertical) --
 189:         /// <summary>
 190:         /// Checks the box list.
 191:         /// </summary>
 192:         /// <param name="htmlHelper">The HTML helper.</param>
 193:         /// <param name="name">The name.</param>
 194:         /// <param name="listInfo">The list info.</param>
 195:         /// <param name="htmlAttributes">The HTML attributes.</param>
 196:         /// <param name="position">The position.</param>
 197:         /// <param name="number">Position.Horizontal則表示每個Row的顯示個數, Position.Vertical則表示要顯示幾個Column</param>
 198:         /// <returns></returns>
 199:         public static MvcHtmlString CheckBoxList(this HtmlHelper htmlHelper,
 200:             string name,
 201:             IEnumerable<SelectListItem> listInfo,
 202:             IDictionary<string, object> htmlAttributes,
 203:             Position position = Position.Horizontal,
 204:             int number = 0)
 205:         {
 206:             if (String.IsNullOrEmpty(name))
 207:             {
 208:                 throw new ArgumentException("必須給這些CheckBoxList一個Tag Name", "name");
 209:             }
 210:             if (listInfo == null)
 211:             {
 212:                 throw new ArgumentNullException("listInfo", "必須要給List<SelectListItem> listInfo");
 213:             }
 214:             if (listInfo.Count() < 1)
 215:             {
 216:                 throw new ArgumentException("List<SelectListItem> listInfo 至少要有一組資料", "listInfo");
 217:             }
 218:  
 219:             StringBuilder sb = new StringBuilder();
 220:             int lineNumber = 0;
 221:  
 222:             switch (position)
 223:             {
 224:                 case Position.Horizontal:
 225:  
 226:                     foreach (SelectListItem info in listInfo)
 227:                     {
 228:                         lineNumber++;
 229:                         sb.Append(CreateCheckBoxItem(info, name, htmlAttributes));
 230:  
 231:                         if (number == 0 || (lineNumber % number == 0))
 232:                         {
 233:                             sb.Append("<br />");
 234:                         }
 235:                     }
 236:                     break;
 237:  
 238:                 case Position.Vertical:
 239:  
 240:                     int dataCount = listInfo.Count();
 241:  
 242:                     // 計算最大顯示的列數(rows)
 243:                     int rows = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(dataCount) / Convert.ToDecimal(number)));
 244:                     if (dataCount <= number || dataCount - number == 1)
 245:                     {
 246:                         rows = dataCount;
 247:                     }
 248:  
 249:                     TagBuilder wrapBuilder = new TagBuilder("div");
 250:                     wrapBuilder.MergeAttribute("style", "float: left; light-height: 25px; padding-right: 5px;");
 251:  
 252:                     string wrapStart = wrapBuilder.ToString(TagRenderMode.StartTag);
 253:                     string wrapClose = string.Concat(wrapBuilder.ToString(TagRenderMode.EndTag), " <div style=\"clear:both;\"></div>");
 254:                     string wrapBreak = string.Concat("</div>", wrapBuilder.ToString(TagRenderMode.StartTag));
 255:  
 256:                     sb.Append(wrapStart);
 257:  
 258:                     foreach (SelectListItem info in listInfo)
 259:                     {
 260:                         lineNumber++;
 261:                         sb.Append(CreateCheckBoxItem(info, name, htmlAttributes));
 262:  
 263:                         if (lineNumber.Equals(rows))
 264:                         {
 265:                             sb.Append(wrapBreak);
 266:                             lineNumber = 0;
 267:                         }
 268:                         else
 269:                         {
 270:                             sb.Append("<br/>");
 271:                         }
 272:                     }
 273:                     sb.Append(wrapClose);
 274:                     break;
 275:             }
 276:  
 277:             return MvcHtmlString.Create(sb.ToString());
 278:         }
 279:  
 280:         internal static string CreateCheckBoxItem(SelectListItem info, string name, IDictionary<string, object> htmlAttributes)
 281:         {
 282:             StringBuilder sb = new StringBuilder();
 283:  
 284:             TagBuilder builder = new TagBuilder("input");
 285:             if (info.Selected)
 286:             {
 287:                 builder.MergeAttribute("checked", "checked");
 288:             }
 289:             builder.MergeAttributes<string, object>(htmlAttributes);
 290:             builder.MergeAttribute("type", "checkbox");
 291:             builder.MergeAttribute("value", info.Value);
 292:             builder.MergeAttribute("name", name);
 293:             sb.Append(builder.ToString(TagRenderMode.Normal));
 294:  
 295:             TagBuilder labelBuilder = new TagBuilder("label");
 296:             labelBuilder.MergeAttribute("for", name);
 297:             labelBuilder.InnerHtml = info.Text;
 298:             sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
 299:  
 300:             return sb.ToString();
 301:         }
 302:         #endregion
 303:     }
 304: }

 

RadioButtonListExtensions.cs

image

   1: using System;
   2: using System.Collections.Generic;
   3: using System.Linq;
   4: using System.Text;
   5: using System.Web.Mvc;
   6: using System.Web.Routing;
   7:  
   8: namespace MvcApplication.Helpers
   9: {
  10:     public static class RadioButtonListExtensions
  11:     {
  12:         #region -- RadioButtonList (Horizontal) --
  13:         /// <summary>
  14:         /// RadioButtonList.
  15:         /// </summary>
  16:         /// <param name="htmlHelper">The HTML helper.</param>
  17:         /// <param name="name">The name.</param>
  18:         /// <param name="listInfo">RadioButtonListInfo.</param>
  19:         /// <returns></returns>
  20:         public static MvcHtmlString RadioButtonList(this HtmlHelper htmlHelper, 
  21:             string name, 
  22:             IEnumerable<SelectListItem> listInfo)
  23:         {
  24:             return htmlHelper.RadioButtonList(name, listInfo, (IDictionary<string, object>)null, 0);
  25:         }
  26:  
  27:         /// <summary>
  28:         /// RadioButtonList.
  29:         /// </summary>
  30:         /// <param name="htmlHelper">The HTML helper.</param>
  31:         /// <param name="name">The name.</param>
  32:         /// <param name="listInfo">RadioButtonListInfo.</param>
  33:         /// <param name="htmlAttributes">The HTML attributes.</param>
  34:         /// <returns></returns>
  35:         public static MvcHtmlString RadioButtonList(this HtmlHelper htmlHelper, 
  36:             string name,
  37:             IEnumerable<SelectListItem> listInfo, 
  38:             object htmlAttributes)
  39:         {
  40:             return htmlHelper.RadioButtonList(
  41:                 name, 
  42:                 listInfo, 
  43:                 (IDictionary<string, object>)new RouteValueDictionary(htmlAttributes), 
  44:                 0);
  45:         }
  46:  
  47:         /// <summary>
  48:         /// RadioButtonList.
  49:         /// </summary>
  50:         /// <param name="htmlHelper">The HTML helper.</param>
  51:         /// <param name="name">The name.</param>
  52:         /// <param name="listInfo">The list info.</param>
  53:         /// <param name="htmlAttributes">The HTML attributes.</param>
  54:         /// <param name="number">每個Row的顯示個數.</param>
  55:         /// <returns></returns>
  56:         public static MvcHtmlString RadioButtonList(this HtmlHelper htmlHelper,
  57:             string name,
  58:             IEnumerable<SelectListItem> listInfo,
  59:             IDictionary<string, object> htmlAttributes,
  60:             int number)
  61:         {
  62:             if (String.IsNullOrEmpty(name))
  63:             {
  64:                 throw new ArgumentException("必須給這些RadioButtonList一個Tag Name", "name");
  65:             }
  66:             if (listInfo == null)
  67:             {
  68:                 throw new ArgumentNullException("listInfo", "必須要給List<RadioButtonListInfo> listInfo");
  69:             }
  70:             if (listInfo.Count() < 1)
  71:             {
  72:                 throw new ArgumentException("List<RadioButtonListInfo> listInfo 至少要有一組資料", "listInfo");
  73:             }
  74:  
  75:             StringBuilder sb = new StringBuilder();
  76:             int lineNumber = 0;
  77:  
  78:             foreach (SelectListItem info in listInfo)
  79:             {
  80:                 lineNumber++;
  81:  
  82:                 TagBuilder builder = new TagBuilder("input");
  83:                 if (info.Selected)
  84:                 {
  85:                     builder.MergeAttribute("checked", "checked");
  86:                 }
  87:                 builder.MergeAttributes<string, object>(htmlAttributes);
  88:                 builder.MergeAttribute("type", "radio");
  89:                 builder.MergeAttribute("value", info.Value);
  90:                 builder.MergeAttribute("name", name);
  91:                 sb.Append(builder.ToString(TagRenderMode.Normal));
  92:  
  93:                 TagBuilder labelBuilder = new TagBuilder("label");
  94:                 labelBuilder.MergeAttribute("for", name);
  95:                 labelBuilder.InnerHtml = info.Text;
  96:                 sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
  97:  
  98:                 if (number == 0 || (lineNumber % number == 0))
  99:                 {
 100:                     sb.Append("<br />");
 101:                 }
 102:             }
 103:             return MvcHtmlString.Create(sb.ToString());
 104:         }
 105:         #endregion
 106:  
 107:         #region -- RadioButtonVertical --
 108:         /// <summary>
 109:         /// Checks the box list vertical.
 110:         /// </summary>
 111:         /// <param name="htmlHelper">The HTML helper.</param>
 112:         /// <param name="name">The name.</param>
 113:         /// <param name="listInfo">The list info.</param>
 114:         /// <param name="htmlAttributes">The HTML attributes.</param>
 115:         /// <param name="columnNumber">The column number.</param>
 116:         /// <returns></returns>
 117:         public static MvcHtmlString RadioButtonVertical(this HtmlHelper htmlHelper,
 118:             string name,
 119:             IEnumerable<SelectListItem> listInfo,
 120:             IDictionary<string, object> htmlAttributes,
 121:             int columnNumber = 1)
 122:         {
 123:             if (String.IsNullOrEmpty(name))
 124:             {
 125:                 throw new ArgumentException("必須給這些RadioButton一個Tag Name", "name");
 126:             }
 127:             if (listInfo == null)
 128:             {
 129:                 throw new ArgumentNullException("listInfo", "必須要給List<RadioButtonInfo> listInfo");
 130:             }
 131:             if (listInfo.Count() < 1)
 132:             {
 133:                 throw new ArgumentException("List<RadioButtonInfo> listInfo 至少要有一組資料", "listInfo");
 134:             }
 135:  
 136:             int dataCount = listInfo.Count();
 137:  
 138:             // calculate number of rows
 139:             int rows = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(dataCount) / Convert.ToDecimal(columnNumber)));
 140:             if (dataCount <= columnNumber || dataCount - columnNumber == 1)
 141:             {
 142:                 rows = dataCount;
 143:             }
 144:  
 145:             TagBuilder wrapBuilder = new TagBuilder("div");
 146:             wrapBuilder.MergeAttribute("style", "float: left; light-height: 25px; padding-right: 5px;");
 147:  
 148:             string wrapStart = wrapBuilder.ToString(TagRenderMode.StartTag);
 149:             string wrapClose = string.Concat(wrapBuilder.ToString(TagRenderMode.EndTag), " <div style=\"clear:both;\"></div>");
 150:             string wrapBreak = string.Concat("</div>", wrapBuilder.ToString(TagRenderMode.StartTag));
 151:  
 152:             StringBuilder sb = new StringBuilder();
 153:             sb.Append(wrapStart);
 154:  
 155:             int lineNumber = 0;
 156:  
 157:             foreach (var info in listInfo)
 158:             {
 159:                 TagBuilder builder = new TagBuilder("input");
 160:                 if (info.Selected)
 161:                 {
 162:                     builder.MergeAttribute("checked", "checked");
 163:                 }
 164:                 builder.MergeAttributes<string, object>(htmlAttributes);
 165:                 builder.MergeAttribute("type", "radio");
 166:                 builder.MergeAttribute("value", info.Value);
 167:                 builder.MergeAttribute("name", name);
 168:                 sb.Append(builder.ToString(TagRenderMode.Normal));
 169:  
 170:                 TagBuilder labelBuilder = new TagBuilder("label");
 171:                 labelBuilder.MergeAttribute("for", name);
 172:                 labelBuilder.InnerHtml = info.Text;
 173:                 sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
 174:  
 175:                 lineNumber++;
 176:  
 177:                 if (lineNumber.Equals(rows))
 178:                 {
 179:                     sb.Append(wrapBreak);
 180:                     lineNumber = 0;
 181:                 }
 182:                 else
 183:                 {
 184:                     sb.Append("<br/>");
 185:                 }
 186:             }
 187:             sb.Append(wrapClose);
 188:             return MvcHtmlString.Create(sb.ToString());
 189:         }
 190:         #endregion
 191:  
 192:         #region -- RadioButtonList (Horizonal, Vertical) --
 193:         /// <summary>
 194:         /// Checks the box list.
 195:         /// </summary>
 196:         /// <param name="htmlHelper">The HTML helper.</param>
 197:         /// <param name="name">The name.</param>
 198:         /// <param name="listInfo">The list info.</param>
 199:         /// <param name="htmlAttributes">The HTML attributes.</param>
 200:         /// <param name="position">The position.</param>
 201:         /// <param name="number">Position.Horizontal則表示每個Row的顯示個數, Position.Vertical則表示要顯示幾個Column</param>
 202:         /// <returns></returns>
 203:         public static MvcHtmlString RadioButtonList(this HtmlHelper htmlHelper,
 204:             string name,
 205:             IEnumerable<SelectListItem> listInfo,
 206:             IDictionary<string, object> htmlAttributes,
 207:             Position position = Position.Horizontal,
 208:             int number = 0)
 209:         {
 210:             if (String.IsNullOrEmpty(name))
 211:             {
 212:                 throw new ArgumentException("必須給這些RadioButtonList一個Tag Name", "name");
 213:             }
 214:             if (listInfo == null)
 215:             {
 216:                 throw new ArgumentNullException("listInfo", "必須要給List<RadioButtonListInfo> listInfo");
 217:             }
 218:             if (listInfo.Count() < 1)
 219:             {
 220:                 throw new ArgumentException("List<RadioButtonListInfo> listInfo 至少要有一組資料", "listInfo");
 221:             }
 222:  
 223:             StringBuilder sb = new StringBuilder();
 224:             int lineNumber = 0;
 225:  
 226:             switch (position)
 227:             {
 228:                 case Position.Horizontal:
 229:  
 230:                     foreach (SelectListItem info in listInfo)
 231:                     {
 232:                         lineNumber++;
 233:                         sb.Append(CreateRadioButtonItem(info, name, htmlAttributes));
 234:  
 235:                         if (number == 0 || (lineNumber % number == 0))
 236:                         {
 237:                             sb.Append("<br />");
 238:                         }
 239:                     }
 240:                     break;
 241:  
 242:                 case Position.Vertical:
 243:  
 244:                     int dataCount = listInfo.Count();
 245:  
 246:                     // 計算最大顯示的列數(rows)
 247:                     int rows = Convert.ToInt32(Math.Ceiling(Convert.ToDecimal(dataCount) / Convert.ToDecimal(number)));
 248:                     if (dataCount <= number || dataCount - number == 1)
 249:                     {
 250:                         rows = dataCount;
 251:                     }
 252:  
 253:                     TagBuilder wrapBuilder = new TagBuilder("div");
 254:                     wrapBuilder.MergeAttribute("style", "float: left; light-height: 25px; padding-right: 5px;");
 255:  
 256:                     string wrapStart = wrapBuilder.ToString(TagRenderMode.StartTag);
 257:                     string wrapClose = string.Concat(wrapBuilder.ToString(TagRenderMode.EndTag), " <div style=\"clear:both;\"></div>");
 258:                     string wrapBreak = string.Concat("</div>", wrapBuilder.ToString(TagRenderMode.StartTag));
 259:  
 260:                     sb.Append(wrapStart);
 261:  
 262:                     foreach (SelectListItem info in listInfo)
 263:                     {
 264:                         lineNumber++;
 265:                         sb.Append(CreateRadioButtonItem(info, name, htmlAttributes));
 266:  
 267:                         if (lineNumber.Equals(rows))
 268:                         {
 269:                             sb.Append(wrapBreak);
 270:                             lineNumber = 0;
 271:                         }
 272:                         else
 273:                         {
 274:                             sb.Append("<br/>");
 275:                         }
 276:                     }
 277:                     sb.Append(wrapClose);
 278:                     break;
 279:             }
 280:  
 281:             return MvcHtmlString.Create(sb.ToString());
 282:         }
 283:  
 284:         /// <summary>
 285:         /// CreateRadioButtonItem
 286:         /// </summary>
 287:         /// <param name="info"></param>
 288:         /// <param name="name"></param>
 289:         /// <param name="htmlAttributes"></param>
 290:         /// <returns></returns>
 291:         internal static string CreateRadioButtonItem(
 292:             SelectListItem info, 
 293:             string name, 
 294:             IDictionary<string, object> htmlAttributes)
 295:         {
 296:             StringBuilder sb = new StringBuilder();
 297:  
 298:             TagBuilder builder = new TagBuilder("input");
 299:             if (info.Selected)
 300:             {
 301:                 builder.MergeAttribute("checked", "checked");
 302:             }
 303:             builder.MergeAttributes<string, object>(htmlAttributes);
 304:             builder.MergeAttribute("type", "radio");
 305:             builder.MergeAttribute("value", info.Value);
 306:             builder.MergeAttribute("name", name);
 307:             sb.Append(builder.ToString(TagRenderMode.Normal));
 308:  
 309:             TagBuilder labelBuilder = new TagBuilder("label");
 310:             labelBuilder.MergeAttribute("for", name);
 311:             labelBuilder.InnerHtml = info.Text;
 312:             sb.Append(labelBuilder.ToString(TagRenderMode.Normal));
 313:  
 314:             return sb.ToString();
 315:         }
 316:         #endregion
 317:     }
 318: }

 

2012-09-28 更新:

之前所提供的「RadioButtonListExtensions」程式碼,上一個版本我把「RadioButtonList」打錯字了!!!

錯的字「RadioButtinList」… 正確的「RadioButtonList」…

至於上面有圖片內容還是使用「RadioButtinList」就算了,不想重新擷圖,所以請各位看到就自動取代替換吧。

 


補充說明

這一次的範例說明網站是用預設的 ASP.NET MVC 4 網站專案範本,如果沒有對預設網站的 CSS 做調整的話,直接使用我所提供的 CheckBoxList or RadioButtonList 於顯示時會怪怪的,

image

並不是我提供的 Html Helper Extensions 有問題或是 Bug,這只是 CSS 的設定不同所導致的,可以對 Content / Site.css 內容的兩個地方做點修改就可以正常顯示了,

image

image


以上

15 則留言:

  1. 您好
    您原本的code 產生出來的CheckBox不能點label就勾選CheckBox
    在TagBuilder 部分加上各自加上 下面code 就可以達到點label就勾選CheckBox
    labelBuilder.MergeAttribute("for", name + info.Value);
    CheckBoxbuilder.MergeAttribute("id", name + info.Value);

    感謝您 提供 複選欄位的 解法

    回覆刪除
  2. how do i reference
    a helper folder

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    回覆
    1. create a [helper] folder, add 3 *.cs files and copy the code, change Namespace(recommand)
      (Position.cs, CheckBoxListExtensions.cs, RadioButtonListExtensions.cs)






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  3. 假如我把(Produce和Dairy Products和Seafood)這三個值勾選起來,
    存到db裡面,而且是在同一張資料表同一個欄位,
    值為(Produce,Dairy Products,Seafood)的話,
    要如何把這三個呈現出是已勾選,其他的是未勾選。

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    回覆
    1. 可以在後端組成 List 或是 SelectList 的時候就做判斷,
      我假設你有將勾選的項目給儲存到資料庫裡,
      那個在後端組成 List 或是 SelectList 的時候,就已經把選項從資料庫抓出來,
      那麼再把你所儲存的選項目抓出來,然後每個項目去比對是否勾選,
      如果有勾選,則該選項的 selected 為 true,反之為 false,
      這種 SelectListItem 操作與 DropDownList 的操作是一樣的,
      可參考「ASP.NET MVC 3 - DropDownList 的基本設定方式」
      http://kevintsengtw.blogspot.tw/2012/09/aspnet-mvc-3-dropdownlist.html

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    2. 我是用兩張資料表,一張是存全部的產品類別,另一張是存產品的資料。
      而存產品資料的資料表裡面有一欄是存勾選的產品類別,所以不是只用一張資料表。
      我沒解釋清楚@@

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    3. Hello, 一樣的作法,既然你是在某個 table 的欄位中存放勾選的資料,
      假設你所存的勾選資料是存產品資料的 id, 並且是以「,」分隔,
      那麼在判斷產品項目是否有勾選的時候,就可以把所存的勾選資料給抓出來,
      然後建立 SelectListItem 的 List 時就可以做判斷。
      做法跟我上面所回覆你的是一樣的,你先試著去實作。

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    4. 一圖勝千文,
      https://dl.dropboxusercontent.com/u/26764200/images/blog/20130715_1506.jpg

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  4. 原本的我是用兩層的foreach來執行迴圈,第二層裡面用if else判斷,造成會出現重覆的核取項出現。(讓我的頭殼卡了三天)
    原來只要用一層就出現了,然後是在selected判斷,我還以為是用if else來做,
    真的太好了,感激中!!!!

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    回覆
    1. 有時候程式的問題都只是一個小環節而形成的,通了就解了。

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  5. 不好意思,想請教您
    若是使用這個checkboxlist的helper,我該如何跟ValidationMessage搭配使用呢?

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    回覆
    1. 你好,可以參考以下兩篇文章
      .
      ASP.NET MVC - CheckBoxList 與 ValidationMessage (ASP.NET MVC 5 with Bootstrap3)
      http://goo.gl/juJwS0
      .
      ASP.NET MVC - CheckBoxList 與 ValidationMessage (ASP.NET MVC 4 without Bootstrap)
      http://goo.gl/43bH7f

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  6. Hi,
    How to get selected values in controller for both the controls

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    回覆
    1. Hello, avinash
      Every Checkbox has same Name,
      so, in Controller's Action method, add parameter use same name,
      ex: CheckBoxList Name use [cities], action's parameter name must use [cities]
      that we can get selected values in Controller.

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