MVC进阶学习--HtmlHelper之GridView控件拓展(三)

1.扩展核心代码

Code
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Web;
5 using System.Web.Mvc.Html;
6 using System.Web.Mvc;
7 using MvcTest.Code;
8 using System.Web.UI;
9 using System.IO;
10 using System.Data;
11
12 namespace MvcTest.Code
13 {
14 public static class GridViewHelper
15 {
16 public static string GridView<T>(this HtmlHelper helper, PageList<T> items, string[] columns, GridViewOption option)
17 {
18 if (columns == null)
19 {
20 columns = typeof(T).GetProperties().Select(p => p.Name).ToArray<string>();
21 }
22
23 if (option.Headers == null)
24 {
25 option.Headers = columns;
26 }
27 else
28 {
29 if (option.Headers.Length != columns.Length)
30 {
31 option.Headers = columns;
32 }
33 }
34
35 HtmlTextWriter writer = new HtmlTextWriter(new StringWriter());
36 writer.RenderBeginTag(HtmlTextWriterTag.Table);
37
38 //标题
39 RenderHeander<T>(helper, writer, columns, option);
40
41 //添加数据行
42 RenderRow<T>(helper, writer, items, columns, option);
43
44 //添加分页
45 RenderPageList<T>(helper, writer, items, columns, option);
46
47 return writer.InnerWriter.ToString(); ;
48 }
49
50
51 /// <summary>
52 /// 添加表头行
53 /// </summary>
54 /// <typeparam name="T"></typeparam>
55 /// <param name="helper"></param>
56 /// <param name="writer"></param>
57 /// <param name="columns"></param>
58 /// <param name="option"></param>
59 /// <returns></returns>
60 public static string RenderHeander<T>(this HtmlHelper helper, HtmlTextWriter writer, string[] columns, GridViewOption option)
61 {
62 writer.RenderBeginTag(HtmlTextWriterTag.Tr);
63 for (int i = 0; i < option.Headers.Length;i++ )
64 {
65 writer.AddAttribute("id",columns[i]);
66 writer.AddAttribute("name", columns[i]);
67 writer.RenderBeginTag(HtmlTextWriterTag.Th);
68 writer.Write(option.Headers[i]);
69 writer.RenderEndTag();
70 }
71
72 //如果有编辑或删除列，则要在原有列的基础上加一列
73 if (option.IsEidt || option.IsDelete)
74 {
75 writer.RenderBeginTag(HtmlTextWriterTag.Th);
76 writer.RenderEndTag();
77 }
78 writer.RenderEndTag();
79 return writer.InnerWriter.ToString();
80 }
81
82 /// <summary>
83 /// 添加数据行
84 /// </summary>
85 /// <param name="helper"></param>
86 /// <param name="writer"></param>
87 /// <param name="item"></param>
88 /// <param name="columns"></param>
89 /// <param name="option"></param>
90 /// <returns></returns>
91 public static string RenderRow<T>(this HtmlHelper helper, HtmlTextWriter writer, PageList<T> items, string[] columns, GridViewOption option)
92 {
93 string value = null;
94 foreach (var item in items)
95 {
96 writer.RenderBeginTag(HtmlTextWriterTag.Tr);
97 for (int i = 0; i < columns.Length; i++)
98 {
99 writer.RenderBeginTag(HtmlTextWriterTag.Td);
100 value = typeof(T).GetProperty(columns[i]).GetValue(item, null).ToString();
101 if (i == 0)
102 {
103 writer.AddAttribute("type", "hidden");
104 writer.AddAttribute("id",items.IdentityName);
105 writer.AddAttribute("name", items.IdentityName);
106 writer.AddAttribute("value", typeof(T).GetProperty(items.IdentityName).GetValue(item, null).ToString());
107 writer.RenderBeginTag(HtmlTextWriterTag.Input);
108 writer.RenderEndTag();
109 writer.Write(value.Length > 20 ? value.Substring(0, 20) : value);
110 }
111 else
112 {
113 writer.Write(value.Length > 20 ? value.Substring(0, 20) : value);
114 }
115 //writer.Write(value);
116 writer.RenderEndTag();
117 }
118 if (option.IsEidt || option.IsDelete)
119 {
120 writer.RenderBeginTag(HtmlTextWriterTag.Td);
121 if (option.IsEidt)
122 {
123 //writer.Write(helper.ActionLink(option.EditButton, null, null, new { @class = "Edit_Link" }) + " ");
124 writer.Write("<a href='#' class='Edit_Link'>编辑</a>   ");
125 }
126 if (option.IsDelete)
127 {
128 writer.Write(helper.ActionLink(option.DeleteButton, option.DeleteAction, new { controller = option.DeleteController, id = typeof(T).GetProperty(items.IdentityName).GetValue(item, null).ToString() }));
129 }
130
131 writer.RenderEndTag();
132 }
133 writer.RenderEndTag();
134 }
135 return writer.InnerWriter.ToString();
136 }
137
138
139 /// <summary>
140 /// 添加分页
141 /// </summary>
142 /// <param name="helper"></param>
143 /// <param name="writer"></param>
144 /// <param name="option"></param>
145 /// <returns></returns>
146 public static string RenderPageList<T>(this HtmlHelper helper, HtmlTextWriter writer, PageList<T> items, string[] columns, GridViewOption option)
147 {
148 writer.RenderBeginTag(HtmlTextWriterTag.Tr);
149 if (option.IsEidt || option.IsDelete)
150 {
151 writer.AddAttribute("colspan", (option.Headers.Length + 1).ToString());
152 }
153 else
154 {
155 writer.AddAttribute("colspan", (option.Headers.Length).ToString());
156 }
157 writer.AddAttribute("align", "center");
158 writer.RenderBeginTag(HtmlTextWriterTag.Td);
159 writer.Write(helper.ActionLink("首页", items.Action, new { controller = items.Controller, pageIndex = 1 }) + "    ");
160 writer.Write(helper.ActionLink("上一页", items.Action, new { controller = items.Controller, pageIndex = items.Page.PageIndex - 1 }) + "    ");
161 writer.Write(items.Page.PageIndex + "/" + items.Page.PageCount + "页    ");
162 writer.Write(helper.ActionLink("下一页", items.Action, new { controller = items.Controller, pageIndex = items.Page.PageIndex + 1 }) + "    ");
163 writer.Write(helper.ActionLink("尾页", items.Action, new { controller = items.Controller, pageIndex = items.Page.PageCount }) + "    ");
164 writer.RenderEndTag();
165 writer.RenderEndTag();
166 writer.RenderEndTag();
167
168 //构建隐藏表单
169 writer.AddStyleAttribute("display","none");
170 writer.RenderBeginTag(HtmlTextWriterTag.Div);
171 writer.AddAttribute("id","form0");
172 writer.AddAttribute("action","/Home/Update");
173 writer.AddAttribute("method","post");
174 writer.RenderBeginTag(HtmlTextWriterTag.Form);
175 foreach (string column in columns)
176 {
177 writer.AddAttribute("type","hidden");
178 writer.AddAttribute("id", column);
179 writer.AddAttribute("name", column);
180 writer.AddAttribute("value", "");
181 writer.RenderBeginTag(HtmlTextWriterTag.Input);
182 writer.RenderEndTag();
183 }
184 writer.RenderEndTag();
185 writer.RenderEndTag();
186
187 return writer.InnerWriter.ToString();
188 }
189 }
190 }
191 (1)
public static string GridView<T>(this HtmlHelper helper, PageList<T> items, string[] columns, GridViewOption option)
this HtmlHelper helper 这个是.net3.0 中的新特性，我们扩展HtmlHelper这个类，使之具有GridView<T>（）这个泛型方法
PageList<T> items 则是指定的数据源(上篇提到过的自定义的数据集合),
string[] columns 这个是指定GridView 显示哪几列，和GridViewOption中的header数组有区别，这个是针对数据库字段或者某个实体的属性，而GridViewOption中的是表格的头部不封显示的字样
(2)

if (columns == null)
{
columns = typeof(T).GetProperties().Select(p => p.Name).ToArray<string>();
}

if (option.Headers == null)
{
option.Headers = columns;
}
else
{
if (option.Headers.Length != columns.Length)
{
option.Headers = columns;
}
}

这个定义了表格标题的匹配规则，如果columns 的值为null，则默认显示该对象的所有属性，这里区分columns和heander数组，同时也匹配了二者之间的关系。如果这两个数组的长度相等，则表头显示自定义的字样，否则都以columns中的字样为主
(3)

HtmlTextWriter writer = new HtmlTextWriter(new StringWriter());
writer.RenderBeginTag(HtmlTextWriterTag.Table);

//标题
RenderHeander<T>(helper, writer, columns, option);

//添加数据行
RenderRow<T>(helper, writer, items, columns, option);

//添加分页
RenderPageList<T>(helper, writer, items, columns, option);

return writer.InnerWriter.ToString(); ;

这段就是调用下面的方法，设置数据

更多方法介绍看下篇