大学学习的java,工作后转成了C#，由于工作需要，全力去学习了C#，学习中，相信大家都会有相同的疑惑，在判断一个字符串是否为空的时候总会用到string.IsNullOrEmpty(s)这个方法，最开始就想到了是不是反射，后面才知道这是c#的扩展方法，后面的内容慢慢讲解我对扩展方法由浅到深的理解与用法。
1：扩展方法的自定义实现，我这里特别用到了判断类型是否为数值类型的方法（可以去比较学习下），里面子定义了4个扩展方法
1 namespace ConsoleApplication1
2 {
3 class Program
4 {
5 static void Main(string[] args)
6 {
7 var i = 32;
8 System.Console.WriteLine(i.GetType().IsNumericType());
9 System.Console.ReadKey();
10 }
11 }
12
13 public static class TestExtension
14 {
15 //老外的代码
16 public static bool IsNumeric(this Type dataType)
17 {
18 if (dataType == null)
19 throw new ArgumentNullException("dataType");
20
21 return (dataType == typeof(int)
22 || dataType == typeof(double)
23 || dataType == typeof(long)
24 || dataType == typeof(short)
25 || dataType == typeof(float)
26 || dataType == typeof(Int16)
27 || dataType == typeof(Int32)
28 || dataType == typeof(Int64)
29 || dataType == typeof(uint)
30 || dataType == typeof(UInt16)
31 || dataType == typeof(UInt32)
32 || dataType == typeof(UInt64)
33 || dataType == typeof(sbyte)
34 || dataType == typeof(Single)
35 );
36 }
37 /// <summary>
38 /// 判断是否为数值类型。
39 /// </summary>
40 /// <param name="t">要判断的类型</param>
41 /// <returns>是否为数值类型</returns>
42 public static bool IsNumericType(this Type t)
43 {
44 var tc = Type.GetTypeCode(t);
45 return (t.IsPrimitive && t.IsValueType && !t.IsEnum && tc != TypeCode.Char && tc != Typ eCode.Boolean) || tc == TypeCode.Decimal;
46 }
47
48 /// <summary>
49 /// 判断是否为可空数值类型。
50 /// </summary>
51 /// <param name="t">要判断的类型</param>
52 /// <returns>是否为可空数值类型</returns>
53 public static bool IsNumericOrNullableNumericType(this Type t)
54 {
55 return t.IsNumericType() || (t.IsNullableType() && t.GetGenericArguments()[0].IsNumeric Type());
56 }
57
58 /// <summary>
59 /// 判断是否为可空类型。
60 /// 注意，直接调用可空对象的.GetType()方法返回的会是其泛型值的实际类型，用其进行此判断肯定返回false。
61 /// </summary>
62 /// <param name="t">要判断的类型</param>
63 /// <returns>是否为可空类型</returns>
64 public static bool IsNullableType(this Type t)
65 {
66 return t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>);
67 }
68
69 }
70 }
2：通过上面的列子可能就只能看出它使用上更为便捷而已，但当我接触到Linq,才发现扩展方法的强大，自己也学着参考改造下Linq的构造方法以增加增加所需要的功能
1 public static class QueryableExtensions
2 {
3 public static IQueryable<T> OrderBy<T>(this IQueryable<T> queryable, string propertyName)
4 {
5 return QueryableHelper<T>.OrderBy(queryable, propertyName, false);
6 }
7 public static IQueryable<T> OrderBy<T>(this IQueryable<T> queryable, string propertyName, b ool desc)
8 {
9 return QueryableHelper<T>.OrderBy(queryable, propertyName, desc);
10 }
11
12 static class QueryableHelper<T>
13 {
14 //为了缓存表达式树
15 private static Dictionary<string, LambdaExpression> cache = new Dictionary<string, Lamb daExpression>();
16 public static IQueryable<T> OrderBy(IQueryable<T> queryable, string propertyName, bool desc)
17 {
18
19 dynamic keySelector = GetLambdaExpression(propertyName);
20 return desc ? Queryable.OrderByDescending(queryable, keySelector) : Queryable.Order By(queryable, keySelector);
21 }
22 private static LambdaExpression GetLambdaExpression(string propertyName)
23 {
24 if (cache.ContainsKey(propertyName)) return cache[propertyName];
25 var param = Expression.Parameter(typeof(T));
26 var body = Expression.Property(param, propertyName);
27 var keySelector = Expression.Lambda(body, param);
28 cache[propertyName] = keySelector;
29 return keySelector;
30 }
31 }
32 }
4：对于数据库的操作，也可以使用扩展方法，我上篇随笔也说了，项目用了IOC，没有在数据库这块用到扩展方法，这可以参考http://www.cnblogs.com/xiaotuni/archive/2012/05/29/2523683.html
5：当使用到MVC框架的时候，看到前端的页面使用Html.BeginForm等一些相同格式语法的时候，我马上意识到这就是MVC里面的扩展方法，转而想是否可以自己也写一些扩展方法，方便自己使用，首先我想到前端Table的遍历，分页等，并着手全部实现，并应用于项目中
Table的遍历，我们在后台写好一个扩展方法类
1 public static class RazorExtensions
2 {
3 public static HelperResult /*List*/ Repeat<T>(this IEnumerable<T> items,
4 Func<T, HelperResult> template)
5 {
6 if (items == null)
7 return new HelperResult(t => t.Write(""));
8
9 return new HelperResult(writer =>
10 {
11 foreach (var item in items)
12 {
13 template(item).WriteTo(writer);
14 }
15 });
16 }
17 }
前端我们引用他的命名空间，如下方式调用：
<tbody>
@Model.Repeat(
@<tr>
<td><ahref="/order/catalog/new/@item.ContractNo">@item.ContractNo</a></td>
<td>@item.StrokeNo</td>
<td>@item.StrokeDesc</td>
<td>@item.ContractStatus</td>
<td>@item.DeptNo</td>
<td>@item.Season</td>
<td>@item.SupplierSeries</td>
<td>@item.CountryCode</td>
<td>@item.ProductDesc</td>
<td>@item.DateLastModified</td>
<td>@item.CreatedTime.Format()</td>
</tr>)
</tbody>
分页控件的实现：
后台：首先我们必须有一个page类
namespace WebPrint.Web.Mvc.Pager
{
public class PagerOptions
{
public PagerOptions()
{
AutoHide = true;
PageIndexParameterName = "pageindex";
NumericPagerItemCount = 10;
AlwaysShowFirstLastPageNumber = false;
ShowPrevNext = true;
NextPageText = ">";
PrevPageText = "<";
ShowNumericPagerItems = true;
ShowFirstLast = true;
FirstPageText = "<<";
LastPageText = ">>";
ShowMorePagerItems = true;
MorePageText = "...";
ShowDisabledPagerItems = true;
PagerItemsSeperator = " ";
ContainerTagName = "div";
InvalidPageIndexErrorMessage = "页索引无效";
PageIndexOutOfRangeErrorMessage = "页索引超出范围";
MaxPageIndex = 0;
FirstPageRouteName = null;
}
/// <summary>
/// 首页使用的路由名称（无页索引参数）
/// </summary>
public string FirstPageRouteName { get; set; }
/// <summary>
/// 当总页数只有一页时是否自动隐藏
/// </summary>
public bool AutoHide { get; set; }
/// <summary>
/// 页索引超出范围时显示的错误消息
/// </summary>
public string PageIndexOutOfRangeErrorMessage { get; set; }
/// <summary>
/// 页索引无效时显示的错误消息
/// </summary>
public string InvalidPageIndexErrorMessage { get; set; }
/// <summary>
/// url中页索引参数的名称
/// </summary>
public string PageIndexParameterName { get; set; }
private string _containerTagName;
/// <summary>
/// 分页控件html容器标签名，默认为div
/// </summary>
public string ContainerTagName
{
get
{
return _containerTagName;
}
set
{
if (string.IsNullOrEmpty(value))
throw new System.ArgumentException("ContainerTagName不能为null或空字符串", "ContainerTagName");
_containerTagName = value;
}
}
/// <summary>
/// whether or not show first and last numeric page number
/// </summary>
public bool AlwaysShowFirstLastPageNumber { get; set; }
/// <summary>
/// 显示的最大数字页索引按钮数
/// </summary>
public int NumericPagerItemCount { get; set; }
/// <summary>
/// 是否显示上页和下页
/// </summary>
public bool ShowPrevNext { get; set; }
/// <summary>
/// 上一页文本
/// </summary>
public string PrevPageText { get; set; }
/// <summary>
/// 下一页文本
/// </summary>
public string NextPageText { get; set; }
/// <summary>
/// 是否显示数字页索引按钮及更多页按钮
/// </summary>
public bool ShowNumericPagerItems { get; set; }
/// <summary>
/// 是否显示第一页和最后一页
/// </summary>
public bool ShowFirstLast { get; set; }
/// <summary>
/// 第一页文本
/// </summary>
public string FirstPageText { get; set; }
/// <summary>
/// 最后一页文本
/// </summary>
public string LastPageText { get; set; }
/// <summary>
/// 是否显示更多页按钮
/// </summary>
public bool ShowMorePagerItems { get; set; }
/// <summary>
/// 更多页按钮文本
/// </summary>
public string MorePageText { get; set; }
/// <summary>
/// 包含分页控件的父容器标签的ID
/// </summary>
public string Id { get; set; }
/// <summary>
/// CSS样式类
/// </summary>
public string CssClass { get; set; }
/// <summary>
/// whether or not show disabled navigation buttons
/// </summary>
public bool ShowDisabledPagerItems { get; set; }
/// <summary>
/// 分页元素之间的分隔符，默认为两个html空格（ ）
/// </summary>
public string PagerItemsSeperator { get; set; }
/// <summary>
/// 限制显示的最大页数，默认值为0，即根据总记录数算出的总页数
/// </summary>
public int MaxPageIndex { get; set; }
}
}
2个生成分页控件HTML代码的类
using System;
using System.Web.Mvc;
using System.Web.Routing;
using WebPrint.Model.Helper;
namespace WebPrint.Web.Mvc.Pager
{
public static class PagerHelper
{
#region Html Pager
private static MvcHtmlString Pager(this HtmlHelper helper, int totalItemCount, int pageSize, int pageIndex,
string actionName, string controllerName,
PagerOptions pagerOptions, string routeName, object routeValues, object htmlAttributes)
{
var totalPageCount = (int) Math.Ceiling(totalItemCount/(double) pageSize);
var builder = new PagerBuilder
(
helper,
actionName,
controllerName,
totalItemCount,
totalPageCount,
pageIndex,
pageSize,
pagerOptions,
routeName,
new RouteValueDictionary(routeValues),
new RouteValueDictionary(htmlAttributes)
);
return builder.RenderPager();
}
public static MvcHtmlString Pager(this HtmlHelper helper, IPagedList pagedList, PagerOptions pagerOptions)
{
//if (pagedList == null)
// return Pager(helper, pagerOptions, null);
return Pager(helper, pagedList.RecordsCount, pagedList.PageSize, pagedList.PageIndex, null, null,
pagerOptions, null, null, null);
}
#endregion
}
}
/*
ASP.NET MvcPager 分页组件
[email protected]杨涛\Webdiyer (http://www.webdiyer.com)
Source code released under Ms-PL license
*/
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
namespace WebPrint.Web.Mvc.Pager
{
internal class PagerBuilder
{
private readonly HtmlHelper html;
private readonly string actionName;
private readonly string controllerName;
private readonly int totalPageCount = 1;
private readonly int totalRecordCount = 1;
private readonly int pageIndex;
private readonly int pageSize;
private readonly PagerOptions pagerOptions;
private readonly RouteValueDictionary routeValues;
private readonly string routeName;
private readonly int startPageIndex = 1;
private readonly int endPageIndex = 1;
private IDictionary<string, object> htmlAttributes;
private const string CopyrightText =
"\r\n<!--MvcPager v2.0 for ASP.NET MVC 4.0+ © 2009-2013 Webdiyer (http://www.webdiyer.com)-->\r\n";
/// <summary>
/// 适用于PagedList为null时
/// </summary>
//internal PagerBuilder(HtmlHelper html,PagerOptions pagerOptions, IDictionary<string, object> htmlAttributes)
//{
// if (pagerOptions == null)
// pagerOptions = new PagerOptions();
// this.html = html;
// this.pagerOptions = pagerOptions;
// this.htmlAttributes = htmlAttributes;
//}
internal PagerBuilder(HtmlHelper html, string actionName, string controllerName, int totalRecordCount,
int totalPageCount, int pageIndex, int pageSize, PagerOptions pagerOptions, string routeName,
RouteValueDictionary routeValues,
IDictionary<string, object> htmlAttributes)
{
if (pagerOptions == null)
pagerOptions = new PagerOptions();
this.html = html;
this.actionName = actionName;
this.controllerName = controllerName;
this.totalRecordCount = totalRecordCount;
if (pagerOptions.MaxPageIndex == 0 || pagerOptions.MaxPageIndex > totalPageCount)
this.totalPageCount = totalPageCount;
else
this.totalPageCount = pagerOptions.MaxPageIndex;
this.pageIndex = pageIndex;
this.pageSize = pageSize;
this.pagerOptions = pagerOptions;
this.routeName = routeName;
this.routeValues = routeValues;
this.htmlAttributes = htmlAttributes;
// start page index
startPageIndex = pageIndex - (pagerOptions.NumericPagerItemCount/2);
if (startPageIndex + pagerOptions.NumericPagerItemCount > this.totalPageCount)
startPageIndex = this.totalPageCount + 1 - pagerOptions.NumericPagerItemCount;
if (startPageIndex < 1)
startPageIndex = 1;
// end page index
endPageIndex = startPageIndex + this.pagerOptions.NumericPagerItemCount - 1;
if (endPageIndex > this.totalPageCount)
endPageIndex = this.totalPageCount;
}
private void AddPrevious(ICollection<PagerItem> results)
{
var item = new PagerItem(pagerOptions.PrevPageText, pageIndex - 1, pageIndex == 1, PagerItemType.PrevPage);
if (!item.Disabled || (item.Disabled && pagerOptions.ShowDisabledPagerItems))
results.Add(item);
}
private void AddFirst(ICollection<PagerItem> results)
{
var item = new PagerItem(pagerOptions.FirstPageText, 1, pageIndex == 1, PagerItemType.FirstPage);
//只有导航按钮未被禁用，或导航按钮被禁用但ShowDisabledPagerItems=true时才添加
if (!item.Disabled || (item.Disabled && pagerOptions.ShowDisabledPagerItems))
results.Add(item);
}
private void AddMoreBefore(ICollection<PagerItem> results)
{
if (startPageIndex > 1 && pagerOptions.ShowMorePagerItems)
{
var index = startPageIndex - 1;
if (index < 1) index = 1;
var item = new PagerItem(pagerOptions.MorePageText, index, false, PagerItemType.MorePage);
results.Add(item);
}
}
private void AddPageNumbers(ICollection<PagerItem> results)
{
for (var pageIndex = startPageIndex; pageIndex <= endPageIndex; pageIndex++)
{
var text = pageIndex.ToString(CultureInfo.InvariantCulture);
//if (pageIndex == this.pageIndex && !string.IsNullOrEmpty(pagerOptions.CurrentPageNumberFormatString))
// text = String.Format(pagerOptions.CurrentPageNumberFormatString, text);
//else if (!string.IsNullOrEmpty(pagerOptions.PageNumberFormatString))
// text = String.Format(pagerOptions.PageNumberFormatString, text);
var item = new PagerItem(text, pageIndex, false, PagerItemType.NumericPage);
results.Add(item);
}
}
private void AddMoreAfter(ICollection<PagerItem> results)
{
if (endPageIndex < totalPageCount)
{
var index = startPageIndex + pagerOptions.NumericPagerItemCount;
if (index > totalPageCount)
{
index = totalPageCount;
}
var item = new PagerItem(pagerOptions.MorePageText, index, false, PagerItemType.MorePage);
results.Add(item);
}
}
private void AddNext(ICollection<PagerItem> results)
{
var item = new PagerItem(pagerOptions.NextPageText, pageIndex + 1, pageIndex >= totalPageCount,
PagerItemType.NextPage);
if (!item.Disabled || (item.Disabled && pagerOptions.ShowDisabledPagerItems))
results.Add(item);
}
private void AddLast(ICollection<PagerItem> results)
{
var item = new PagerItem(pagerOptions.LastPageText, totalPageCount, pageIndex >= totalPageCount,
PagerItemType.LastPage);
if (!item.Disabled || (item.Disabled && pagerOptions.ShowDisabledPagerItems))
results.Add(item);
}
/// <summary>
/// 根据页索引生成分页导航Url
/// </summary>
/// <param name="pageIndex">要生成导航链接的页索引</param>
/// <returns>分页导航链接Url</returns>
private string GenerateUrl(int pageIndex)
{
ViewContext viewContext = html.ViewContext;
//若要生成url的页索引小于1或大于总页数或等于当前页索引时，无需生成分页导航链接
if (pageIndex > totalPageCount || pageIndex == this.pageIndex)
return null;
var routeValues1 = new RouteValueDictionary(viewContext.RouteData.Values);
AddQueryStringToRouteValues(routeValues1, viewContext);
if (this.routeValues != null && this.routeValues.Count > 0)
{
foreach (var de in this.routeValues)
{
if (!routeValues1.ContainsKey(de.Key))
{
routeValues1.Add(de.Key, de.Value);
}
else
{
routeValues1[de.Key] = de.Value; //手动添加的RouteValues具有高优先级
}
}
}
var pageValue = viewContext.RouteData.Values[pagerOptions.PageIndexParameterName];
string routeName = this.routeName;
// 设置Route Value中的分页导航Url参数值，pageIndex为0时生成适用于脚本的导航链接
if (pageIndex == 0)
routeValues1[pagerOptions.PageIndexParameterName] = "__" + pagerOptions.PageIndexParameterName + "__";
else
{
if (pageIndex == 1)
{
if (!string.IsNullOrWhiteSpace(pagerOptions.FirstPageRouteName))
//如果显式指定了FirstPageRouteName，则使用此Route
{
routeName = pagerOptions.FirstPageRouteName;
routeValues1.Remove(pagerOptions.PageIndexParameterName); //去除页索引参数
viewContext.RouteData.Values.Remove(pagerOptions.PageIndexParameterName);
}
else
{
var curRoute = viewContext.RouteData.Route as Route;
//判断当前Route是否为Route类型，如果是，则判断该Route中页索引参数默认值是否为UrlParameter.Optional，或页索引参数是否存在于该Route Url的参数列表中，如果参数默认值为UrlParameter.Optional或分页参数名不存在于Route Url参数中，则从当前的RouteValue列表中去除该参数
if (curRoute != null &&
(curRoute.Defaults[pagerOptions.PageIndexParameterName] == UrlParameter.Optional ||
!curRoute.Url.Contains("{" + pagerOptions.PageIndexParameterName + "}")))
{
routeValues1.Remove(pagerOptions.PageIndexParameterName); //去除页索引参数
viewContext.RouteData.Values.Remove(pagerOptions.PageIndexParameterName);
}
else
{
routeValues1[pagerOptions.PageIndexParameterName] = pageIndex;
}
}
}
else
{
routeValues1[pagerOptions.PageIndexParameterName] = pageIndex;
}
}
var routes = html.RouteCollection;
string url;
if (!string.IsNullOrEmpty(routeName))
url = UrlHelper.GenerateUrl(routeName, actionName, controllerName, routeValues1, routes,
viewContext.RequestContext, false);
else
url = UrlHelper.GenerateUrl(null, actionName, controllerName, routeValues1, routes,
viewContext.RequestContext, false);
if (pageValue != null)
viewContext.RouteData.Values[pagerOptions.PageIndexParameterName] = pageValue;
return url;
}
/// <summary>
/// 生成最终的分页Html代码
/// </summary>
/// <returns></returns>
internal MvcHtmlString RenderPager()
{
//return null if total page count less than or equal to 1
if (totalPageCount <= 1 && pagerOptions.AutoHide)
return MvcHtmlString.Create(CopyrightText);
//Display error message if pageIndex out of range
if ((pageIndex > totalPageCount && totalPageCount > 0) || pageIndex < 1)
{
return
MvcHtmlString.Create(string.Format("{0}<div style=\"color:red;font-weight:bold\">{1}</div>{0}",
CopyrightText, pagerOptions.PageIndexOutOfRangeErrorMessage));
}
var pagerItems = new List<PagerItem>();
//First page
if (pagerOptions.ShowFirstLast)
AddFirst(pagerItems);
// Prev page
if (pagerOptions.ShowPrevNext)
AddPrevious(pagerItems);
if (pagerOptions.ShowNumericPagerItems)
{
if (pagerOptions.AlwaysShowFirstLastPageNumber && startPageIndex > 1)
pagerItems.Add(new PagerItem("1", 1, false, PagerItemType.NumericPage));
// more page before numeric page buttons
if (pagerOptions.ShowMorePagerItems &&
((!pagerOptions.AlwaysShowFirstLastPageNumber && startPageIndex > 1) ||
(pagerOptions.AlwaysShowFirstLastPageNumber && startPageIndex > 2)))
AddMoreBefore(pagerItems);
// numeric page
AddPageNumbers(pagerItems);
// more page after numeric page buttons
if (pagerOptions.ShowMorePagerItems &&
((!pagerOptions.AlwaysShowFirstLastPageNumber && endPageIndex < totalPageCount) ||
(pagerOptions.AlwaysShowFirstLastPageNumber && totalPageCount > endPageIndex + 1)))
AddMoreAfter(pagerItems);
if (pagerOptions.AlwaysShowFirstLastPageNumber && endPageIndex < totalPageCount)
pagerItems.Add(new PagerItem(totalPageCount.ToString(CultureInfo.InvariantCulture), totalPageCount,
false,
PagerItemType.NumericPage));
}
// Next page
if (pagerOptions.ShowPrevNext)
AddNext(pagerItems);
//Last page
if (pagerOptions.ShowFirstLast)
AddLast(pagerItems);
var sb = new StringBuilder();
foreach (PagerItem item in pagerItems)
{
sb.Append(GeneratePagerElement(item));
}
var tb = new TagBuilder(pagerOptions.ContainerTagName);
if (!string.IsNullOrEmpty(pagerOptions.Id))
tb.GenerateId(pagerOptions.Id);
if (!string.IsNullOrEmpty(pagerOptions.CssClass))
tb.AddCssClass(pagerOptions.CssClass);
tb.MergeAttributes(htmlAttributes, true);
sb.Length -= pagerOptions.PagerItemsSeperator.Length;
var startRecords = ((pageIndex - 1)*pageSize) + 1;
var endRecords = pageIndex*pageSize;
if (endRecords > totalRecordCount)
endRecords = totalRecordCount;
var recordsCountText =
string.Format("<span class=\"summary\">{0} - {1}, {2} records</span>",
startRecords, endRecords, totalRecordCount);
tb.InnerHtml = sb.ToString() + recordsCountText;
return
MvcHtmlString.Create(CopyrightText + /*pagerScript +*/ tb.ToString(TagRenderMode.Normal) + CopyrightText);
}
private MvcHtmlString GeneratePagerElement(PagerItem item)
{
//pager item link
string url = GenerateUrl(item.PageIndex);
if (item.Disabled) //first,last,next or previous page
return CreateWrappedPagerElement(item,
String.Format("<a class=\"disabled\" disabled=\"disabled\">{0}</a>", item.Text));
return CreateWrappedPagerElement(item,
string.IsNullOrEmpty(url)
? HttpUtility.HtmlEncode(item.Text)
: String.Format("<a href=\"{0}\">{1}</a>", url, item.Text));
}
private MvcHtmlString CreateWrappedPagerElement(PagerItem item, string el)
{
string navStr = el;
switch (item.Type)
{
case PagerItemType.FirstPage:
case PagerItemType.LastPage:
case PagerItemType.NextPage:
case PagerItemType.PrevPage:
break;
case PagerItemType.MorePage:
break;
case PagerItemType.NumericPage:
if (item.PageIndex == pageIndex)
{
navStr = string.Format("<a href=\"javascript:void(0);\" class=\"current\">{0}</a>", el);
}
break;
}
return MvcHtmlString.Create(navStr + pagerOptions.PagerItemsSeperator);
}
private void AddQueryStringToRouteValues(RouteValueDictionary routeValues, ViewContext viewContext)
{
if (routeValues == null)
routeValues = new RouteValueDictionary();
var rq = viewContext.HttpContext.Request.QueryString;
if (rq != null && rq.Count > 0)
{
var invalidParams = new[]
{"x-requested-with", "xmlhttprequest", pagerOptions.PageIndexParameterName.ToLower()};
foreach (string key in rq.Keys)
{
// 添加url参数到路由中
if (!string.IsNullOrEmpty(key) && Array.IndexOf(invalidParams, key.ToLower()) < 0)
{
var kv = rq[key];
routeValues[key] = kv;
}
}
}
}
}
}
使用扩展方法：
public static MvcHtmlString Paginaton(this HtmlHelper helper, IPagedList pagedList)
{
var pagerOptions = new PagerOptions
{
PageIndexParameterName = "page",
CssClass = "pagination",
ShowFirstLast = false,
AlwaysShowFirstLastPageNumber = true,
ShowMorePagerItems = true,
NumericPagerItemCount = 5,
PagerItemsSeperator = string.Empty,
};
return helper.Pager(pagedList, pagerOptions);
}
前端直接引用调用：
<div class="pagination_div"> @Html.Paginaton(Model) </div>
总结：相对于鹤冲天大哥的见解，我对于扩张方法的使用差的太远，但一般的场景也可以用到扩展方法的地方都还是可以轻松应对，所以我们平常就该对深入的学习认识他，才能在后面应用自如
时间： 2024-10-13 17:40:29