c# - asp.net gridview 中的分页和排序问题

Question

我有一个 GridView ，我在其中实现了分页和排序。当我对表格进行排序并选择第 2 页时，排序将丢失，第二个 20 条记录将显示在 desc 中，如 gridview 绑定(bind)中所述

private DataSet BindGridView(string field)
        {
         DataSet ds = new DataSet()
      string userQuery = "Select tbl_User.UserID, tbl_User.FirstName from tbl_user order by tbl_user.UserID desc";
      UserTable.DataBind();
            return ds;
        }



<asp:GridView ID="UserTable" runat="server"   PageSize="20" AllowPaging="True"
                    SelectedIndex="0" DataKeyNames="UserID"  OnRowDataBound="UserTable_RowDataBound"                   
   AutoGenerateColumns="false" OnPageIndexChanging="gridView_PageIndexChanging"  AllowSorting="true" OnSorting="gridView_Sorting">

如何保留排序并执行分页，我将排序状态存储在 session 中，如何使用它来执行分页。

protected void gridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            UserTable.PageIndex = e.NewPageIndex;        
            UserTable.DataBind();
            DataView myView = new DataView(BindGridView(Session["useremail"].ToString()).Tables[0]);
        }

     protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
        {
            string sortExpression = null;
            if ((Session["UsersortExpression"] == null))
            {
                sortExpression = null;
            }
            else
            {
                sortExpression = (Session["UsersortExpression"].ToString());
            }
            if (sortExpression == e.SortExpression)
            {
                sortExpression += " DESC";
            }
            else
            {
                sortExpression = e.SortExpression;
            }
            DataView myView = new DataView(BindGridView(Session["useremail"].ToString()).Tables[0]);
            myView.Sort = sortExpression;
            UserTable.DataSource = myView;
            UserTable.DataBind();
            //save sort state 
            Session.Add("UsersortExpression", sortExpression);
        }

Answer 1

您可以使用 ViewState 字符串变量对源查询应用排序来存储排序字段和排序方向:

确保 ViewState 变量设置为默认值:

ViewState["sortDir"] = "DESC"; 
ViewState["sortField"] = "tbl_user.UserID";

然后，修改您的查询字符串:

string userQuery = 
"Select tbl_User.UserID, tbl_User.FirstName " +
"from tbl_user " + 
"ORDER BY " + (String)ViewState["sortField"] + " " + (String)ViewState["sortDir"];

包含在 OnSorting 中:

protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
{
    // Set new sort direction and sort field
    if ((String)ViewState["sortDir"] == "DESC"){ViewState["sortDir"] = "ASC";}
    else { ViewState["sortDir"] = "DESC"; }
    ViewState["sortField"] = e.SortExpression;

    // Rebind
    ...     
}

这样，您的源数据已预先排序，您无需担心使用 myView.Sort 或遇到任何分页/排序冲突。