通用Dapper分页

1、定义一个用来装载适合所有类的分页结果类

PageDataView的Items一个泛型属性，所以可以适合所有的类，简洁而通用

public class PageDataView<T>
{
     private int _TotalNum;
     public PageDataView()
    {
        this._Items = new List<T>();
    }
    public int TotalNum
    {
        get { return _TotalNum; }
        set { _TotalNum = value; }
    }
    private IList<T> _Items;
    public IList<T> Items
    {
        get { return _Items; }
        set { _Items = value; }
    }
    public int CurrentPage { get; set; }
    public int TotalPageCount { get; set; }
}

2、定义一个通用的获取分页数据的类

ProcGetPageData就是通用的分页存储过程

Create PROCEDURE [dbo].[ProcGetPageData]
(  @TableName VARCHAR(1000), --表名,多表是请使用 tA a inner join tB b On a.AID = b.AID
   @PrimaryKey NVARCHAR(100),    --主键，可以带表头 a.AID
   @Fields NVARCHAR(2000) = '*',--读取字段
   @Condition NVARCHAR(3000) = '',--Where条件
   @CurrentPage INT = 1,    --开始页码
   @PageSize INT = 10,        --页大小
   @Sort NVARCHAR(200) = '', --排序字段
   @RecordCount INT = 0 OUT
)
AS
DECLARE @strWhere VARCHAR(2000)
DECLARE @strsql NVARCHAR(3900)
IF @Condition IS NOT NULL AND len(ltrim(rtrim(@Condition)))>0
  BEGIN
   SET @strWhere = ' WHERE ' + @Condition + ' '
  END
ELSE
  BEGIN
   SET @strWhere = ''
  END
        
IF (charindex(ltrim(rtrim(@PrimaryKey)),@Sort)=0)
BEGIN
    IF(@Sort='')
        SET @Sort = @PrimaryKey + ' DESC '
    ELSE
        SET @Sort = @Sort+ ' , '+@PrimaryKey + ' DESC '
END
SET @strsql = 'SELECT @RecordCount = Count(1) FROM ' + @TableName + @strWhere  
EXECUTE sp_executesql @strsql ,N'@RecordCount INT output',@RecordCount OUTPUT
IF @CurrentPage = 1 --第一页提高性能
BEGIN 
  SET @strsql = 'SELECT TOP ' + str(@PageSize) +' '+@Fields
              + '  FROM ' + @TableName + ' ' + @strWhere + ' ORDER BY  '+ @Sort
END 
ELSE
  BEGIN
    /* Execute dynamic query */    
    DECLARE @START_ID NVARCHAR(50)
    DECLARE @END_ID NVARCHAR(50)
    SET @START_ID = CONVERT(NVARCHAR(50),(@CurrentPage - 1) * @PageSize + 1)
    SET @END_ID = CONVERT(NVARCHAR(50),@CurrentPage * @PageSize)
    SET @strsql =  ' SELECT *
   FROM (SELECT ROW_NUMBER() OVER(ORDER BY '+@Sort+') AS rownum, 
     '+@Fields+ '
      FROM '+@TableName + @strWhere +') AS XX
   WHERE rownum BETWEEN '+@START_ID+' AND ' +@END_ID +' ORDER BY XX.rownum ASC'
  END
EXEC(@strsql)
RETURN

3、获取分页数据

调用分页存储过程的公共类：

public class Common
{
    public static string DBConnString = System.Configuration.ConfigurationManager.ConnectionStrings["DBContext"].ConnectionString;
 
    public static System.Data.IDbConnection GetConn()
    {
        return new System.Data.SqlClient.SqlConnection(Common.DBConnString);
    }
 
    public static PageDataView<T> GetPageData<T>(PageCriteria criteria,object param=null)
    {
        using (var conn = Common.GetConn())
        {
            var p = new DynamicParameters();
            string proName = "ProcGetPageData";
            p.Add("TableName", criteria.TableName);
            p.Add("PrimaryKey", criteria.PrimaryKey);
            p.Add("Fields", criteria.Fields);
            p.Add("Condition", criteria.Condition);
            p.Add("CurrentPage", criteria.CurrentPage);
            p.Add("PageSize", criteria.PageSize);
            p.Add("Sort", criteria.Sort);
            p.Add("RecordCount", dbType: DbType.Int32, direction: ParameterDirection.Output);
            
            conn.Open();
            var pageData = new PageDataView<T>();
            pageData.Items = conn.Query<T>(proName, p, commandType: CommandType.StoredProcedure).ToList();
            conn.Close();
            pageData.TotalNum = p.Get<int>("RecordCount");
            pageData.TotalPageCount = Convert.ToInt32(Math.Ceiling(pageData.TotalNum * 1.0 / criteria.PageSize));
            pageData.CurrentPage = criteria.CurrentPage > pageData.TotalPageCount ? pageData.TotalPageCount : criteria.CurrentPage;
            return pageData;
        }
    }
}

下面是dapper通用万能的泛型分页公共类的使用方法

public static PageDataView<MSys_Admin> GetList(string name, string loginName, int page,int pageSize=10)
{
    PageCriteria criteria = new PageCriteria();
    criteria.Condition = "1=1";
    if (!string.IsNullOrEmpty(name))
        criteria.Condition += string.Format(" and Name like '%{0}%'", name);
    if (!string.IsNullOrEmpty(loginName))
        criteria.Condition += string.Format(" and LoginName like '%{0}%'", loginName);
    criteria.CurrentPage = page;
    criteria.Fields = "*";
    criteria.PageSize = pageSize;
    criteria.TableName = "Sys_Admin a";
    criteria.PrimaryKey = "UID";
    var r = Common.GetPageData<MSys_Admin>(criteria);
    return r;
}

PageCriteria是一个封装查询条件相关信息的类。

public class PageCriteria
{
    private string _TableName;
    public string TableName
    {
        get { return _TableName; }
        set { _TableName = value; }
    }
    private string _Fileds = "*";
    public string Fields
    {
        get { return _Fileds; }
        set { _Fileds = value; }
    }
    private string _PrimaryKey = "ID";
    public string PrimaryKey
    {
        get { return _PrimaryKey; }
        set { _PrimaryKey = value; }
    }
    private int _PageSize = 10;
    public int PageSize
    {
        get { return _PageSize; }
        set { _PageSize = value; }
    }
    private int _CurrentPage = 1;
    public int CurrentPage
    {
        get { return _CurrentPage; }
        set { _CurrentPage = value; }
    }
    private string _Sort = string.Empty;
    public string Sort
    {
        get { return _Sort; }
        set { _Sort = value; }
    }
    private string _Condition = string.Empty;
    public string Condition
    {
        get { return _Condition; }
        set { _Condition = value; }
    }
    private int _RecordCount;
    public int RecordCount
    {
        get { return _RecordCount; }
        set { _RecordCount = value; }
    }
}

4、视图绑定

视图文件的头部加上：

@model PageDataView<MSys_Admin>

<table cellspacing="1" cellpadding="3" class="tablehead" style="background:#CCC;">
    <thead>
        <tr>
            <th align="center">名称</th>
            <th align="center">登录名</th>
            <th align="center">添加时间</th>
            <th align="center">操作</th>
        </tr>
    </thead>
    <tbody>
        @if (Model != null)
        {
            foreach (var item in Model.Items)
            {
                <tr>
                    <td align="center">@item.Name</td>
                    <td align="center">@item.LoginName</td>
                    <td align="center">@item.CreateTime.ToString("yyyy-MM-dd HH:mm:ss")</td>
                    <td align="center">
                        <form method="post" action="@Url.Action("Delete")">
                            <input type="hidden" name="UID" value="@item.UID" />
                            <input type="submit" onclick="return confirm('确定要删除吗？')" value="删除" class="btn" />
                            <a href="@Url.Action("Edit", new {ID=item.UID })" class="add">修改</a>&nbsp;&nbsp;
                        </form>
                    </td>
                </tr>
            }
        }
    </tbody>
</table>
<!--tab end-->
<div class="pagination">
    @Html.PageLinks(Model, p => string.Format("/Admin?name={0}&loginName={1}&page={2}", ViewBag.Name,@ViewBag.LoginName, p), 10)
</div>

文章转载自：蓝狐软件工作室 » 原创--ASP.NET MVC基于dapper的通用万能的泛型分页实例