Question

我有一个Business Layer类，它使用LINQ将IQueryable数据返回到用户层中的GridView。我希望它只返回一页数据;但是，它返回整个查询。我听说分页应该可以工作，但是每个页面都会返回数百或数千行，并抛出除pagesize中设置的所有行。

这是LINQ查询（稍微编辑一下）

        public IQueryable<ScoredMatch> List()
    {
        var dc = new PAQcDataLayerDataContext();
        var matches = (
            from m in dc.ScoredRecordMatches
            join c in dc.Customers on m.CustomerId equals c.CustomerId
            orderby m.PAQNumber
            select new ScoredMatch()
            {
                Id = m.Id,
                PAQId = (int)m.PAQId,
                PAQVersion = (int)m.PAQVersion,  
                JobTitleMatch = (bool)m.JobTitleMatch,
                OrgNameMatch = (bool)m.OrgNameMatch,
                IncumbentNameMatch = (bool)m.IncumbentNameMatch,
            });

        return matches;
    }

这是GridView：

<asp:GridView ID="grdMatches" runat="server" AutoGenerateColumns="false" CssClass="gridview"
    AlternatingRowStyle-CssClass="even" AllowPaging="true" AllowSorting="true" PageSize="10"
    DataKeyNames="Id" OnPageIndexChanging="grdMatches_PageIndexChanging" OnSorting="grdMatches_Sorting"
    AutoGenerateSelectButton="True" OnSelectedIndexChanging="grdMatches_SelectedIndexChanging">
    <Columns>
        <asp:BoundField DataField="PAQNumber" HeaderText="PAQ #" SortExpression="PAQNumber" />
        <asp:BoundField DataField="ScoredNumber" HeaderText="Score #" SortExpression="ScoredNumber" />
        <asp:BoundField DataField="CustomerId" HeaderText="Cust #" SortExpression="CustomerId" />
        <asp:BoundField DataField="Customer" HeaderText="Customer" SortExpression="Customer" />
        <asp:BoundField DataField="Department" HeaderText="Department" SortExpression="Department" />
        <asp:BoundField DataField="DOTNumber" HeaderText="DOT #" SortExpression="DOTNumber" />
        <asp:CheckBoxField DataField="OrgNameMatch" HeaderText="Org Match" />
        <asp:CheckBoxField DataField="JobTitleMatch" HeaderText="Job Match" />
        <asp:CheckBoxField DataField="IncumbentNameMatch" HeaderText="Inc Match" />
    </Columns>
</asp:GridView>

以下是加载Gridview的代码：

grdMatches.DataSource = new ScoredMatch().List();
grdMatches.DataBind();

执行分页的代码：

   protected void grdMatches_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        grdMatches.DataSource = new ScoredMatch().List();
        grdMatches.PageIndex = e.NewPageIndex;
        grdMatches.DataBind();
    }

Answer 1

如果您只想要当前页面，则应在LINQ查询中使用Skip和Take来获得所需的结果。

例如：

 yourQuery.Skip((currentPage - 1) * pageSize).Take(pageSize).Select(....

这将为您提供应该在结果集中显示的项目，而不是其他内容。

查看以下文章，该文章将向您展示如何更详细地设置它：

http://www.dbtutorials.com/display/linq-to-sql-paging-cs.aspx

Answer 2

    protected void grdMatches_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        // not sure where to get "pageSize" with a grid view but would assume it is there someplace.
        grdMatches.DataSource = new ScoredMatch()
            .Skip(e.NewPageIndex * pageSize)
            .Take(pageSize)
            .List();

        grdMatches.PageIndex = e.NewPageIndex;
        grdMatches.DataBind();
    }

绑定到IQueryable LINQ查询的Gridview返回整个查询而不是单个页面

2 个答案: