Razor视图中DropDownList数据绑定的简化
这只是自己写的一个class，用来简化绑定ViewModel属性的方式. enjoy it.
实际使用：
简单类型下拉框，String和不包括枚举的各基元类型
1 @Html.ComboxListFor(m => m.Month,new []{1,2,3,4,5,6,7,8,9,10,11,12}, "--月--", new { @class = "someStyle" })
枚举下拉框
1 @Html.ComboxEnumListFor(m => m.IDType, typeof(IDType), "--请选择证件类型--")
稍特殊类型下拉框，下面例子只是其中一种方式，不列举了
1 @Html.ComboxListFor(x => x.YourCity, CityBLL.GetList(), "CityName", "CityID", "--请选择城市--", new { @class = "someStyle" })
抛具体依赖的代码
1 using System.Collections.Generic;
2 using System.Linq;
3 using System.Linq.Expressions;
4 using System.Web.Mvc.Html;
5
6 namespace System.Web.Mvc
7 {
8 /// <summary>
9 /// Extended the HtmlHelper for DropDownList
10 /// </summary>
11 public static class ComboxExtensions
12 {
13
14 #region 简单类型下拉框
15
16 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values)
17 {
18 return ComboxListFor(htmlHelper, expression, values, new object());
19 }
20
21 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, object htmlAttributes)
22 {
23 return ComboxListFor(htmlHelper, expression, values, null, new object());
24 }
25
26 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string optionLabel)
27 {
28 return ComboxListFor(htmlHelper, expression, values, optionLabel, new object());
29 }
30
31 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string optionLabel, object htmlAttributes)
32 {
33 return ComboxListForIt(htmlHelper, expression, values, null, null, optionLabel, htmlAttributes);
34 }
35
36 #endregion
37
38 #region 枚举下拉框
39
40 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
41 {
42 return ComboxEnumListFor(htmlHelper, expression, enumType, new object());
43 }
44
45 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, object htmlAttributes)
46 {
47 return ComboxEnumListFor(htmlHelper, expression, enumType, null, new object());
48 }
49
50 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, string optionLabel)
51 {
52 return ComboxEnumListFor(htmlHelper, expression, enumType, optionLabel, new object());
53 }
54
55 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, string optionLabel, object htmlAttributes)
56 {
57 if (!enumType.IsEnum)
58 {
59 throw new ArgumentException("参数必须为枚举类型");
60 }
61
62 var enumItems1 = (from Enum e in Enum.GetValues(enumType)
63 select new KeyValuePair<Enum,string>(e,EnumUtils.GetDescription(e))
64 ).ToList();
65
66 return ComboxListForIt(htmlHelper, expression, enumItems1, "Key", "Value", optionLabel, htmlAttributes);
67 }
68
69 #endregion
70
71 #region 稍特殊类型下拉框，ViewModel属性对应的待选项是个另外一个对象的属性集合
72
73 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField)
74 {
75 return ComboxListFor(htmlHelper, expression, values,dataValueField, dataTextField, new object());
76 }
77
78 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values,string dataValueField, string dataTextField, object htmlAttributes)
79 {
80 return ComboxListFor(htmlHelper, expression, values,dataValueField, dataTextField, null, new object());
81 }
82
83 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values,string dataValueField, string dataTextField, string optionLabel)
84 {
85 return ComboxListFor(htmlHelper, expression, values, dataValueField, dataTextField, optionLabel, new object());
86 }
87
88 public static MvcHtmlString ComboxListFor<TModel, TProperty,TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField, string optionLabel, object htmlAttributes)
89 {
90 return ComboxListForIt(htmlHelper, expression, values, dataValueField, dataTextField, optionLabel, htmlAttributes);
91 }
92
93 #endregion
94
95 #region base，其实只有这个
96
97 private static MvcHtmlString ComboxListForIt<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField, string optionLabel, object htmlAttributes)
98 {
99 Type tPropertyType = typeof(TPropertyType);
100
101 var modelMetadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
102 var selectValue = new object();
103
104 if (modelMetadata.Model != null)
105 {
106 selectValue = modelMetadata.Model;
107 }
108
109 SelectList selectList;
110
111 if (tPropertyType == typeof(int)
112 || tPropertyType == typeof(uint)
113 || tPropertyType == typeof(long)
114 || tPropertyType == typeof(ulong)
115 || tPropertyType == typeof(long)
116 || tPropertyType == typeof(ulong)
117 || tPropertyType == typeof(short)
118 || tPropertyType == typeof(ushort)
119 || tPropertyType == typeof(byte)
120 || tPropertyType == typeof(sbyte)
121 || tPropertyType == typeof(decimal)
122 )
123 {
124 var values1 = values.Select(x => new CBItem(x));
125 selectList = new SelectList(values1, "Value","Text",selectValue);
126 }
127 else
128 {
129
130 if (tPropertyType.IsPrimitive || tPropertyType == typeof (string))
131 {
132 selectList = new SelectList(values, selectValue);
133 }
134 else
135 {
136 if (dataTextField != null && dataValueField != null)
137 {
138 selectList = new SelectList(values, dataValueField, dataTextField, selectValue);
139 }
140 else
141 {
142 selectList = new SelectList(values, selectValue);
143 }
144 }
145
146 }
147
148 return htmlAttributes == null
149 ? (optionLabel == null
150 ? htmlHelper.DropDownListFor(expression, selectList)
151 : htmlHelper.DropDownListFor(expression, selectList, optionLabel))
152 : (optionLabel == null
153 ? htmlHelper.DropDownListFor(expression, selectList, htmlAttributes)
154 : htmlHelper.DropDownListFor(expression, selectList, optionLabel, htmlAttributes));
155 }
156
157 /// <summary>
158 /// 一个辅助的待选项类
159 /// </summary>
160 public class CBItem
161 {
162
163 private string _text = String.Empty;
164 private object _value = default(object);
165
166 public CBItem()
167 { }
168
169 public CBItem(object value, string text)
170 {
171 _text = text;
172 _value = value;
173 }
174
175 public CBItem(object value)
176 {
177 _text = value.ToString();
178 _value = value;
179 }
180
181 /// <summary>
182 /// Text
183 /// </summary>
184 public string Text
185 {
186 get { return _text; }
187 set { _text = value; }
188 }
189
190 /// <summary>
191 /// Value
192 /// </summary>
193 public object Value
194 {
195 get { return _value; }
196 set { _value = value; }
197 }
198
199 }
200
201 #endregion
202
203 }
204 }
2 using System.Linq;
3 using System.Linq.Expressions;
4 using System.Web.Mvc.Html;
5
6 namespace System.Web.Mvc
7 {
8 /// <summary>
9 /// Extended the HtmlHelper for DropDownList
10 /// </summary>
11 public static class ComboxExtensions
12 {
13
14 #region 简单类型下拉框
15
16 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values)
17 {
18 return ComboxListFor(htmlHelper, expression, values, new object());
19 }
20
21 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, object htmlAttributes)
22 {
23 return ComboxListFor(htmlHelper, expression, values, null, new object());
24 }
25
26 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string optionLabel)
27 {
28 return ComboxListFor(htmlHelper, expression, values, optionLabel, new object());
29 }
30
31 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string optionLabel, object htmlAttributes)
32 {
33 return ComboxListForIt(htmlHelper, expression, values, null, null, optionLabel, htmlAttributes);
34 }
35
36 #endregion
37
38 #region 枚举下拉框
39
40 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
41 {
42 return ComboxEnumListFor(htmlHelper, expression, enumType, new object());
43 }
44
45 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, object htmlAttributes)
46 {
47 return ComboxEnumListFor(htmlHelper, expression, enumType, null, new object());
48 }
49
50 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, string optionLabel)
51 {
52 return ComboxEnumListFor(htmlHelper, expression, enumType, optionLabel, new object());
53 }
54
55 public static MvcHtmlString ComboxEnumListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, string optionLabel, object htmlAttributes)
56 {
57 if (!enumType.IsEnum)
58 {
59 throw new ArgumentException("参数必须为枚举类型");
60 }
61
62 var enumItems1 = (from Enum e in Enum.GetValues(enumType)
63 select new KeyValuePair<Enum,string>(e,EnumUtils.GetDescription(e))
64 ).ToList();
65
66 return ComboxListForIt(htmlHelper, expression, enumItems1, "Key", "Value", optionLabel, htmlAttributes);
67 }
68
69 #endregion
70
71 #region 稍特殊类型下拉框，ViewModel属性对应的待选项是个另外一个对象的属性集合
72
73 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField)
74 {
75 return ComboxListFor(htmlHelper, expression, values,dataValueField, dataTextField, new object());
76 }
77
78 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values,string dataValueField, string dataTextField, object htmlAttributes)
79 {
80 return ComboxListFor(htmlHelper, expression, values,dataValueField, dataTextField, null, new object());
81 }
82
83 public static MvcHtmlString ComboxListFor<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values,string dataValueField, string dataTextField, string optionLabel)
84 {
85 return ComboxListFor(htmlHelper, expression, values, dataValueField, dataTextField, optionLabel, new object());
86 }
87
88 public static MvcHtmlString ComboxListFor<TModel, TProperty,TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField, string optionLabel, object htmlAttributes)
89 {
90 return ComboxListForIt(htmlHelper, expression, values, dataValueField, dataTextField, optionLabel, htmlAttributes);
91 }
92
93 #endregion
94
95 #region base，其实只有这个
96
97 private static MvcHtmlString ComboxListForIt<TModel, TProperty, TPropertyType>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IEnumerable<TPropertyType> values, string dataValueField, string dataTextField, string optionLabel, object htmlAttributes)
98 {
99 Type tPropertyType = typeof(TPropertyType);
100
101 var modelMetadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
102 var selectValue = new object();
103
104 if (modelMetadata.Model != null)
105 {
106 selectValue = modelMetadata.Model;
107 }
108
109 SelectList selectList;
110
111 if (tPropertyType == typeof(int)
112 || tPropertyType == typeof(uint)
113 || tPropertyType == typeof(long)
114 || tPropertyType == typeof(ulong)
115 || tPropertyType == typeof(long)
116 || tPropertyType == typeof(ulong)
117 || tPropertyType == typeof(short)
118 || tPropertyType == typeof(ushort)
119 || tPropertyType == typeof(byte)
120 || tPropertyType == typeof(sbyte)
121 || tPropertyType == typeof(decimal)
122 )
123 {
124 var values1 = values.Select(x => new CBItem(x));
125 selectList = new SelectList(values1, "Value","Text",selectValue);
126 }
127 else
128 {
129
130 if (tPropertyType.IsPrimitive || tPropertyType == typeof (string))
131 {
132 selectList = new SelectList(values, selectValue);
133 }
134 else
135 {
136 if (dataTextField != null && dataValueField != null)
137 {
138 selectList = new SelectList(values, dataValueField, dataTextField, selectValue);
139 }
140 else
141 {
142 selectList = new SelectList(values, selectValue);
143 }
144 }
145
146 }
147
148 return htmlAttributes == null
149 ? (optionLabel == null
150 ? htmlHelper.DropDownListFor(expression, selectList)
151 : htmlHelper.DropDownListFor(expression, selectList, optionLabel))
152 : (optionLabel == null
153 ? htmlHelper.DropDownListFor(expression, selectList, htmlAttributes)
154 : htmlHelper.DropDownListFor(expression, selectList, optionLabel, htmlAttributes));
155 }
156
157 /// <summary>
158 /// 一个辅助的待选项类
159 /// </summary>
160 public class CBItem
161 {
162
163 private string _text = String.Empty;
164 private object _value = default(object);
165
166 public CBItem()
167 { }
168
169 public CBItem(object value, string text)
170 {
171 _text = text;
172 _value = value;
173 }
174
175 public CBItem(object value)
176 {
177 _text = value.ToString();
178 _value = value;
179 }
180
181 /// <summary>
182 /// Text
183 /// </summary>
184 public string Text
185 {
186 get { return _text; }
187 set { _text = value; }
188 }
189
190 /// <summary>
191 /// Value
192 /// </summary>
193 public object Value
194 {
195 get { return _value; }
196 set { _value = value; }
197 }
198
199 }
200
201 #endregion
202
203 }
204 }
