asp.net-mvc-3 - ASP.NET MVC3 WebGrid - 自定义的服务器端排序

Question

有没有办法在调用 sort 时覆盖默认的 MVC3 WebGrid 排序行为以调用我的 Controller (它将执行服务器端排序并返回数据)？

谢谢你的帮助!

Answer 1

您可以将服务器端排序的数据以及有关有多少记录的信息传递给 webgrid。 http://msdn.microsoft.com/en-us/magazine/hh288075.aspx有一个有用的演练。我正在执行数据库级别的排序/过滤/分页以最大限度地减少传递的数据量。如果我传递客户拥有的所有 70,000 个对象，以便他们可以看到第 1 页上的 25 个对象，我认为我的网络服务器不会喜欢我。这几乎是您需要的一切，除了非常轻量级的 View 模型，它只是包装了您的 IEnumerable 集合带有一些额外的分页数据。

由于 Web 网格仅使用查询字符串 vars 来决定要做什么，因此您需要使用 get 方法形式。并且您需要以 webgrid 知道如何读取它的方式在查询字符串中包含排序字段/方向。所以你最终得到像 localhost/example/admin/thing?thingName=Hyatt&City=&State=TX&Country=&sort=city&sortdir=ASC 这样的网址

Controller :

    public ActionResult Index(string thingName, string city, string state, string country, int page = 1)
            {
                const int pageSize = 25;                
                int totalRecords = 0; 
                IEnumerable<Thing> things = ThingModel.GetPagedSortedLocationsForCustomer(customerId, sort, sortdir, out totalRecords, pageSize, page, thingName, city, state, country);

                PagedThings viewModel = new PagedThings(pageSize, page, totalRecords, things);

                return View(viewModel);
            }

看法:

@model ExampleCompany.Area.ViewModels.PagedThings 

@{  



using (Html.BeginForm("Index", "ThingaMaBob", System.Web.Mvc.FormMethod.Get))
{

    <label for="ThingName">ThingName</label>@Html.TextBox("ThingName", "")
    <label for="City">City</label>@Html.TextBox("City", "")
    <label for="State">State</label>@Html.TextBox("State", "")
    <label for="Country">Country</label>@Html.TextBox("Country", "")
    <input type="submit" value="Filter" />

    <br />
    var grid = new WebGrid(canPage: true, rowsPerPage: Model.PageSize, canSort: true);
    grid.Bind(Model.Things, rowCount: Model.TotalRows, autoSortAndPage: false);
    grid.Pager(WebGridPagerModes.All);

        @grid.GetHtml(htmlAttributes: new { id = "grid"},
        columns: grid.Columns(
            //ommitted
            grid.Column("thingName", "Thing"),
        ));

    Html.Hidden(grid.SortFieldName, grid.SortColumn);
    Html.Hidden(grid.SortDirectionFieldName, grid.SortDirection == SortDirection.Ascending ? "ASC" : "DESC");
}

模型:

public static IEnumerable<Thing> GetPagedSortedThingsForCustomer(int customerid, String sortby, String sorttype, out int totalRecords, int pageSize, int pageIndex, string thingName, string city, string state, string country)
        {
            var tmp = new List<Thing>();
            int total = 0;

            dynamic dr = OurDBUtility.ReturnDR("ExampleProc_GetThingsSortedPaged", ConnectionInfo.ExampleConnection, customerid, sortby, sorttype, pageSize, pageIndex, thingName, city, state, country);
            {
                while (dr.Read())
                {
                    var tmpThing = new Thing();
                    tmpThing.LoadFromDr(dr);
                    tmp.Add(tmpThing);
                    if (total == 0)
                    {
                        total = (int)dr["TOTAL_THINGS"];
                    }
                }
            }
            totalRecords = total;

            return tmp;
        }

使用动态 sql 处理 - 是的，如果你愿意，你可以使用 Linq-to-Sql 或其他技术，但我是老派:

 CREATE PROCEDURE ExampleProc_GetThingsSortedPaged
      ( @CustomerId  int
       , @sortby    nvarchar(60)
      , @sorttype   nvarchar(60)
      , @pageSize int
      , @pageIndex int
      , @thingName nvarchar(255) = null
      , @city nvarchar(30) = null
      , @state nvarchar(30) = null
      , @country char(2) = null
      )
    as

        DECLARE @strSql      nvarchar(3000) 
        --calculate paging rows
        declare @startRow int, @endRow int
        --e.g. if you have a page size of 10, page 1 = 1 - 10, page 2 = 11 -20 
        set @startRow = ((@pageIndex - 1) * @pageSize) + 1
        set @endRow = @startRow + @pageSize - 1

        if @thingName = ''
            set @thingName = null
        if @city = ''
            set @city = null
        if @state = ''
            set @state = null
        if @country = ''
            set @country = null

        --return total for webgrid, accounting for filter
        declare @totalThings int
        select @totalThings = COUNT(*)
        from EXAMPLE_TABLE T with(nolock)
        where CUSTOMER_ID = @CustomerId
            AND (T.THING_NAME LIKE @thingName + '%' OR @thingName is null)              
            AND (T.CITY LIKE @city + '%' or @city is null) 
            AND (T.STATE LIKE @state + '%' or @state is null) 
            AND (T.COUNTRY = @country or @country is null)



        DECLARE @ParameterDefinition AS NVARCHAR(200)


        set @ParameterDefinition = '@totalThings int, @CustomerId INT, @startRow INT, @endRow INT, @thingName nvarchar(255), @city nvarchar(30), @state nvarchar(30), @country char(2)'

        --When we need to do dynamic sql it is better to use paramterization, but you cannot do (ORDER BY @sortBy).     
        SET @strSql = N'SELECT * from
                        (
                        select ROW_NUMBER() OVER (ORDER BY T.' + @sortby + ' ' + @sorttype + ') as Row, 
                            @totalThings  [TOTAL_THINGS],
                             T.THING_ID, T.THING_NAME, T.ADDRESS, T.CITY,  T.STATE, 
                            T.ZIP_CODE, T.COUNTRY 
                        FROM EXAMPLE_TABLE T
                        WHERE T.CUSTOMER_ID = @CustomerId 
                          AND (T.THING_NAME LIKE @thingName + ''%'' OR @thingName is null)              
                          AND (T.CITY LIKE @city + ''%'' or @city is null) 
                          AND (T.STATE LIKE @state + ''%'' or @state is null) 
                          AND (T.COUNTRY = @country or @country is null)
                           ) paged
                        where Row between @startRow and @endRow 
                        ORDER BY Row'

        --print @strSql
        EXECUTE sp_executesql @strSql, @ParameterDefinition, @totalThings, @CustomerId, @startRow, @endRow, @thingName, @city, @state, @country


    GO

使用 CTE 进行处理:

CREATE PROCEDURE ExampleProc_GetThingsSortedPaged
  ( @CustomerID  int
  , @sortby    nvarchar(60)
  , @sorttype   nvarchar(60)
  , @pageSize int = 25
  , @pageIndex int = 1
  , @thingName nvarchar(255) = null
  , @city varchar(30) = null
  , @state nvarchar(30) = null
  , @country char(2) = null
  )
as



declare @startRow int
declare @endRow int

SET @startRow = ((@pageIndex - 1) * @pageSize) + 1;
SET @endRow = @startRow + @pageSize - 1;

set @sortby = replace(LOWER(@sortby), '_', '')
SET @sorttype = LOWER(@sorttype)

if @sorttype != 'asc' and @sorttype != 'desc'
begin
      set @sorttype = 'asc'
end

;with cte_things as (
      SELECT 
            CASE
                  WHEN @sortby ='country' AND @sorttype = 'asc'  then row_number() over (order by C.COUNTRY_NAME ASC)
                  WHEN @sortby ='country' AND @sorttype = 'desc' then row_number() over (order by C.COUNTRY_NAME DESC)

                  WHEN @sortby ='state' AND @sorttype = 'asc'  then row_number() over (order by STATE ASC) 
                  WHEN @sortby ='state' AND @sorttype = 'desc' then row_number() over (order by STATE DESC)

                  WHEN @sortby ='city' AND @sorttype = 'asc'  then row_number() over (order by CITY ASC)
                  WHEN @sortby ='city' AND @sorttype = 'desc' then row_number() over (order by CITY DESC)

                  WHEN @sortby ='thingname' AND @sorttype = 'desc' then row_number() over (order by THING_NAME DESC) 
                  ELSE row_number() over (order by THING_NAME ASC)
            END AS Row
            ,T.THING_ID, T.THING_NAME, T.THING_TYPE, T.ADDRESS, T.CITY, T.STATE
            , T.ZIP_CODE, T.COUNTRY_CODE, C.COUNTRY_NAME, T.PHONE_NUMBER
            , T.LATITUDE, T.LONGITUDE
            FROM EXAMPLE_TABLE L 
            join COUNTRIES C 
                  on C.COUNTRY_CODE = L.COUNTRY_CODE
            where
                  T.CUSTOMER_ID = @CustomerId 
                  and L.CITY = ISNULL(@city, CITY)
                  and L.STATE = ISNULL(@state, STATE)
                  and L.COUNTRY_CODE = ISNULL(@country, L.COUNTRY_CODE)
                  and L.THING_NAME = ISNULL(@thingName, THING_NAME)
)
, cte_total as (select COUNT(*) as TOTAL_THINGS from cte_things)
, cte_all as (select cte_things.*, cte_total.TOTAL_THINGS from cte_things cross join cte_total)

SELECT * FROM cte_all
where
      Row >= @startRow
      and Row <= @endRow  
ORDER BY Row



GO