文章出處

asp.net mvc 自定義Pager實現分頁

Intro

一個WEB應用程序中經常會用到數據分頁，本文將實現一個簡單通用的分頁組件，包含一個 PagerModel (用來保存頁碼信息)，一個 HtmlHelper 的 Pager 擴展方法和一個 PagedListModel<T> 分頁數據模型。

pager效果圖如下：

pager

PagerModel 分頁模型

PagerModel 用來保存分頁信息，代碼實現如下：

 1     /// <summary>
 2     /// PagerModel 分頁模型
 3     /// </summary>
 4     public class PagerModel
 5     {
 6         public int PageIndex { get; set; }
 7 
 8         public int PageSize { get; set; }
 9 
10         public int PageCount { get; private set; }
11 
12         public int TotalCount { get; set; }
13 
14         public PagerModel(int totalCount)
15         {
16             PageIndex = 1;
17             PageSize = 10;
18             TotalCount = totalCount;
19             PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
20         }
21 
22         public PagerModel(int pageSize, int totalCount)
23         {
24             PageIndex = 1;
25             PageSize = pageSize;
26             TotalCount = totalCount;
27             PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
28         }
29 
30         public PagerModel(int pageIndex, int pageSize, int totalCount)
31         {
32             PageIndex = pageIndex;
33             PageSize = pageSize;
34             TotalCount = totalCount;
35             PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
36         }
37     }

PagerModel

  /// <summary>
  /// PagerModel 分頁模型
  /// </summary>
  public class PagerModel
  {
      public int PageIndex { get; set; }

      public int PageSize { get; set; }

      public int PageCount { get; private set; }

      public int TotalCount { get; set; }

      public PagerModel(int totalCount)
      {
          PageIndex = 1;
          PageSize = 10;
          TotalCount = totalCount;
          PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
      }

      public PagerModel(int pageSize, int totalCount)
      {
          PageIndex = 1;
          PageSize = pageSize;
          TotalCount = totalCount;
          PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
      }

      public PagerModel(int pageIndex, int pageSize, int totalCount)
      {
          PageIndex = pageIndex;
          PageSize = pageSize;
          TotalCount = totalCount;
          PageCount = Convert.ToInt32(Math.Ceiling(TotalCount * 1.0 / PageSize));
      }
  }

Pager擴展方法

Pager擴展方法可根據自己的需求進行定制話實現，Pager擴展方法需要一個PagerModel類型的參數來生成頁碼，我這里是用的bootstrap的樣式來做的分頁，整個系統用的是同一個樣式的分頁所以把樣式直接寫死在代碼里了。
Pager這里的代碼重構做的不是太好：

樣式直接寫死，前端不好維護

 1     /// <summary>
 2     /// PagerHelper 分頁幫助類
 3     /// </summary>
 4     public static class PagerHelper
 5     {
 6         public static MvcHtmlString Pager(this HtmlHelper helper, PagerModel pager)
 7         {
 8             StringBuilder sbHtmlText = new StringBuilder();
 9             sbHtmlText.Append("<div style=\"text-align:center\"><nav><ul  class=\"pagination\">");
10             if (pager.PageIndex <= 1)
11             {
12                 sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>");
13             }
14             else
15             {
16                 sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData(1)\" aria-label=\"1\"><span aria-hidden=\"true\">&laquo;</span></a></li>", pager.PageIndex - 1);
17                 sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\">{0}</a></li>", pager.PageIndex - 1);
18             }
19             sbHtmlText.AppendFormat("<li class=\"active\"><a href=\"javascript:void()\">{0}<span class=\"sr-only\">(current)</span></a></li>", pager.PageIndex);
20             if (pager.PageIndex >= pager.PageCount)
21             {
22                 sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>");
23             }
24             else
25             {
26                 sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\">{0}</a></li>", pager.PageIndex + 1);
27                 sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>", pager.PageIndex + 1);
28             }
29             sbHtmlText.Append("</ul></nav>");
30             sbHtmlText.AppendFormat("<div><span>每頁有<strong>{0}</strong>條數據，一共有<strong>{1}</strong>頁，總計<strong>{2}</strong>條數據</span></div></div>", pager.PageSize, pager.PageCount, pager.TotalCount);            
31             return MvcHtmlString.Create(sbHtmlText.ToString());
32         }
33 
34         public static MvcHtmlString Pager(this HtmlHelper helper, PagerModel pager, Func<int, string> onPageChange)
35         {
36             StringBuilder sbHtmlText = new StringBuilder();
37             sbHtmlText.Append("<div style=\"text-align:center\"><nav><ul  class=\"pagination\">");
38             if (pager.PageIndex <= 1)
39             {
40                 sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>");
41             }
42             else
43             {
44                 sbHtmlText.AppendFormat("<li><a href=\"{0}\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>", onPageChange(pager.PageIndex - 1));
45                 sbHtmlText.AppendFormat("<li><a href=\"{0}\">{1}</a></li>", onPageChange(pager.PageIndex - 1), pager.PageIndex - 1);
46             }
47             sbHtmlText.AppendFormat("<li class=\"active\"><a href=\"javascript:void()\">{0}<span class=\"sr-only\">(current)</span></a></li>", pager.PageIndex);
48             if (pager.PageIndex >= pager.PageCount)
49             {
50                 sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>");
51             }
52             else
53             {
54                 sbHtmlText.AppendFormat("<li><a href=\"{0}\">{1}</a></li>", onPageChange(pager.PageIndex+1),pager.PageIndex + 1);
55                 sbHtmlText.AppendFormat("<li><a href=\"{0}\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>", onPageChange(pager.PageIndex + 1));
56             }
57             sbHtmlText.Append("</ul></nav>");
58             sbHtmlText.AppendFormat("<div><span>每頁有<strong>{0}</strong>條數據，一共有<strong>{1}</strong>頁，總計<strong>{2}</strong>條數據</span></div></div>", pager.PageSize, pager.PageCount, pager.TotalCount);
59             return MvcHtmlString.Create(sbHtmlText.ToString());
60         }
61     }

PagerHelper

  /// <summary>
  /// PagerHelper 分頁幫助類
  /// </summary>
  public static class PagerHelper
  {
      public static MvcHtmlString Pager(this HtmlHelper helper, PagerModel pager)
      {
          StringBuilder sbHtmlText = new StringBuilder();
          sbHtmlText.Append("<div style=\"text-align:center\"><nav><ul class=\"pagination\">");
          if (pager.PageIndex <= 1)
          {
              sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>");
          }
          else
          {
              sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>", pager.PageIndex - 1);
              sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\">{0}</a></li>", pager.PageIndex - 1);
          }
          sbHtmlText.AppendFormat("<li class=\"active\"><a href=\"javascript:void()\">{0}<span class=\"sr-only\">(current)</span></a></li>", pager.PageIndex);
          if (pager.PageIndex >= pager.PageCount)
          {
              sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>");
          }
          else
          {
              sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\">{0}</a></li>", pager.PageIndex + 1);
              sbHtmlText.AppendFormat("<li><a href=\"javascript:loadData({0})\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>", pager.PageIndex + 1);
          }
          sbHtmlText.Append("</ul></nav>");
          sbHtmlText.AppendFormat("<div><span>每頁有<strong>{0}</strong>條數據，一共有<strong>{1}</strong>頁，總計<strong>{2}</strong>條數據</span></div></div>", pager.PageSize, pager.PageCount, pager.TotalCount);            
          return MvcHtmlString.Create(sbHtmlText.ToString());
      }
  }

利用 Func<> 簡單重構了一下代碼，可以自定義翻頁事件

   public static MvcHtmlString Pager(this HtmlHelper helper, PagerModel pager, Func<int, string> onPageChange)
   {
       StringBuilder sbHtmlText = new StringBuilder();
       sbHtmlText.Append("<div style=\"text-align:center\"><nav><ul  class=\"pagination\">");
       if (pager.PageIndex <= 1)
       {
           sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>");
       }
       else
       {
           sbHtmlText.AppendFormat("<li><a href=\"{0}\" aria-label=\"Previous\"><span aria-hidden=\"true\">&laquo;</span></a></li>", onPageChange(pager.PageIndex - 1));
           sbHtmlText.AppendFormat("<li><a href=\"{0}\">{1}</a></li>", onPageChange(pager.PageIndex - 1), pager.PageIndex - 1);
       }
       sbHtmlText.AppendFormat("<li class=\"active\"><a href=\"javascript:void()\">{0}<span class=\"sr-only\">(current)</span></a></li>", pager.PageIndex);
       if (pager.PageIndex >= pager.PageCount)
       {
           sbHtmlText.Append("<li class=\"disabled\"><a href=\"javascript:void()\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>");
       }
       else
       {
           sbHtmlText.AppendFormat("<li><a href=\"{0}\">{1}</a></li>", onPageChange(pager.PageIndex+1),pager.PageIndex + 1);
           sbHtmlText.AppendFormat("<li><a href=\"{0}\" aria-label=\"Next\"><span aria-hidden=\"true\">&raquo;</span></a></li>", onPageChange(pager.PageIndex + 1));
       }
       sbHtmlText.Append("</ul></nav>");
       sbHtmlText.AppendFormat("<div><span>每頁有<strong>{0}</strong>條數據，一共有<strong>{1}</strong>頁，總計<strong>{2}</strong>條數據</span></div></div>", pager.PageSize, pager.PageCount, pager.TotalCount);
       return MvcHtmlString.Create(sbHtmlText.ToString());
   }

關于樣式修改維護的問題，找到一種解決方案，可以將分頁代碼的樣式封裝在一個分部視圖partial，在需要分頁的頁面視圖，引用這個分部視圖并且將分頁模型信息 PagerModel 傳遞給這個分部視圖

PagedListModel 分頁數據模型

PagedListModel 用來封裝返回到視圖 View 的數據和分頁模型 PagerModel，實現代碼如下

 1     /// <summary>
 2     /// 數據分頁模型
 3     /// </summary>
 4     /// <typeparam name="T">數據類型</typeparam>
 5     public class PagedListModel<T> where T : class, new()
 6     {
 7         public List<T> Data { get; set; }
 8 
 9         public PagerModel Pager { get; set; }
10     }

PagedListModel

  public class PagedListModel<T> where T : class, new()
  {
      public List<T> Data { get; set; }

      public PagerModel Pager { get; set; }
  }

控制器數據處理

控制器處理代碼如下：
search 是一個包含了 PageIndex 和 PageSize 的請求參數

 1             int rowsCount = 0;
 2             try
 3             {
 4                 List<Models.BlockEntity> blockList = BusinessHelper.BlockEntityHelper.GetPagedList(search.PageIndex, search.PageSize, out rowsCount, whereLambda, b => b.BlockTime, false);
 5                 PagerModel pager = new PagerModel(search.PageIndex, search.PageSize, rowsCount);
 6                 PagedListModel<Models.BlockEntity> dataList = new PagedListModel<Models.BlockEntity>() { Pager = pager, Data = blockList };
 7                 return View(dataList);
 8             }
 9             catch (Exception ex)
10             {
11                 logger.Error(ex);
12                 throw;
13             }

Controller

       int rowsCount = 0;
       try
       {
           List<Models.BlockEntity> blockList = new Business.BLLBlockEntity().GetPagedList(search.PageIndex, search.PageSize, out rowsCount, whereLambda, b => b.BlockTime, false);//記錄日志
           PagerModel pager = new PagerModel(search.PageIndex, search.PageSize, rowsCount);//定義Pager Model
           PagedListModel<Models.BlockEntity> dataList = new PagedListModel<Models.BlockEntity>() { Pager = pager, Data = blockList };//定義返回到 View 的 PagedListModel
           return View(dataList);
       }
       catch (Exception ex)
       {
           logger.Error(ex);//記錄日志
           throw;
       }

頁面處理

首先在頁面頂部聲明 model 模型

  @model PagedListModel<Models.BlockEntity>

在頁面上遍歷數據

  @foreach (Models.BlockEntity item in Model.Data)

在需要添加分頁信息的地方使用 HtmlHelper 的 Pager 擴展方法

  @Html.Pager(Model.Pager)

View代碼示例

 1 @model PagedListModel<Models.BlockEntity>
 2 <table class="table table-hover">
 3     <thead>
 4         <tr>
 5             <th>黑名單類型</th>
 6             <th>黑名單內容</th>
 7             <th>拉入黑名單時間</th>
 8             <th>狀態</th>
 9             <th>操作</th>
10         </tr>
11     </thead>
12     <tbody>
13         @foreach (Models.BlockEntity item in Model.Data)
14         {
15             string className = "bg-success";
16             if (!item.IsActive)
17             {
18                 className = "bg-danger";
19             }
20              <tr class="@className">
21                     <td>
22                         @item.BlockType.TypeName
23                     </td>
24                     <td>
25                         @item.BlockValue
26                     </td>
27                     <td>
28                         @item.BlockTime
29                     </td>
30                     <td>
31                         @if (item.IsActive)
32                     {
33                             <span>啟用</span>
34                         }
35                         else
36                         {
37                             <span>禁用</span>
38                         }
39                     </td>
40                     <td>
41                         @if (item.IsActive)
42                     {
43                             <button type="button" class='btn btn-warning' onclick="UpdateStatus('@item.BlockId', '@item.BlockValue',-1,this)">禁用</button>
44                         }
45                         else
46                         {
47                             <button type="button" class='btn btn-warning' onclick="UpdateStatus('@item.BlockId','@item.BlockValue',1,this)">啟用</button>
48                         }
49                         <button type="button" class="btn btn-danger" onclick="DeleteEntity('@item.BlockId','@item.BlockValue',this)">刪除</button>
50                     </td>
51                 </tr>
52             }
53     </tbody>
54 </table>
55 @Html.Pager(Model.Pager)