GridView排序：SortDirection总是升序

Question

我有一个gridview，当用户点击标题时我需要对其元素进行排序 它的数据源是一个List对象。

aspx以这种方式定义：

<asp:GridView ID="grdHeader" AllowSorting="true" AllowPaging="false" 
    AutoGenerateColumns="false" Width="780" runat="server"  OnSorting="grdHeader_OnSorting" EnableViewState="true">
    <Columns>
        <asp:BoundField DataField="Entitycode" HeaderText="Entity" SortExpression="Entitycode" />
        <asp:BoundField DataField="Statusname" HeaderText="Status" SortExpression="Statusname" />
        <asp:BoundField DataField="Username" HeaderText="User" SortExpression="Username" />
    </Columns>
</asp:GridView>

背后的代码是这样定义的：
首次加载：

protected void btnSearch_Click(object sender, EventArgs e)
{
    List<V_ReportPeriodStatusEntity> items = GetPeriodStatusesForScreenSelection();
    this.grdHeader.DataSource = items;
    this.grdHeader.DataBind();
}

当用户点击标题时：

protected void grdHeader_OnSorting(object sender, GridViewSortEventArgs e)
{
    List<V_ReportPeriodStatusEntity> items = GetPeriodStatusesForScreenSelection();
    items.Sort(new Helpers.GenericComparer<V_ReportPeriodStatusEntity>(e.SortExpression, e.SortDirection));
    grdHeader.DataSource = items;
    grdHeader.DataBind();
}

我的问题是e.SortDirection始终设置为Ascending 我有一个类似代码的网页，效果很好，e.SortDirection在Ascending和Descending之间交替。

我做错了什么？

Answer 1

Session和Viewstate的问题在于，如果页面上有多个gridview，您还必须跟踪存储SortColumn和Direction的gridview控件。

Session和Viewstate的替代方法是向Gridview添加2个属性，并以这种方式跟踪Column和Direction。

以下是一个例子：

private void GridViewSortDirection(GridView g, GridViewSortEventArgs e, out SortDirection d, out string f)
{
    f = e.SortExpression;
    d = e.SortDirection;

    //Check if GridView control has required Attributes
    if (g.Attributes["CurrentSortField"] != null && g.Attributes["CurrentSortDir"] != null)
    {
        if (f == g.Attributes["CurrentSortField"])
        {
            d = SortDirection.Descending;
            if (g.Attributes["CurrentSortDir"] == "ASC")
            {
                d = SortDirection.Ascending;
            }
        }

        g.Attributes["CurrentSortField"] = f;
        g.Attributes["CurrentSortDir"] = (d == SortDirection.Ascending ? "DESC" : "ASC");
    }

}

Answer 2

您可以使用会话变量来存储最新的Sort Expression，并在下次对网格进行排序时将网格的排序表达式与存储最后一个排序表达式的Session变量进行比较。如果列相等，则检查先前排序的方向并按相反方向排序。

示例：

DataTable sourceTable = GridAttendence.DataSource as DataTable;
DataView view = new DataView(sourceTable);
string[] sortData = Session["sortExpression"].ToString().Trim().Split(' ');
if (e.SortExpression == sortData[0])
{
    if (sortData[1] == "ASC")
    {
        view.Sort = e.SortExpression + " " + "DESC";
        this.ViewState["sortExpression"] = e.SortExpression + " " + "DESC";
    }
    else
    {
        view.Sort = e.SortExpression + " " + "ASC";
        this.ViewState["sortExpression"] = e.SortExpression + " " + "ASC";
    }
}
else
{
    view.Sort = e.SortExpression + " " + "ASC";
    this.ViewState["sortExpression"] = e.SortExpression + " " + "ASC";
}

Answer 3

一个简单的解决方案：

protected SortDirection GetSortDirection(string column)
{
    SortDirection nextDir = SortDirection.Ascending; // Default next sort expression behaviour.
    if (ViewState["sort"] != null && ViewState["sort"].ToString() == column)
    {   // Exists... DESC.
        nextDir = SortDirection.Descending;
        ViewState["sort"] = null;
    }
    else
    {   // Doesn't exists, set ViewState.
        ViewState["sort"] = column;
    }
    return nextDir;
}

非常类似于ViewState上的默认GridView排序和轻量级。

<强> USAGE：

protected void grdHeader_OnSorting(object sender, GridViewSortEventArgs e)
{
    List<V_ReportPeriodStatusEntity> items = GetPeriodStatusesForScreenSelection();

    items.Sort(new Helpers.GenericComparer<V_ReportPeriodStatusEntity>(e.SortExpression, GetSortDirection(e.SortExpression));
    grdHeader.DataSource = items;
    grdHeader.DataBind();
}

Answer 4

自动双向排序仅适用于SQL数据源。不幸的是，MSDN中的所有文档都假设您正在使用它，因此GridView可能会有点令人沮丧。

我这样做的方法是自己跟踪订单。例如：

    protected void OnSortingResults(object sender, GridViewSortEventArgs e)
    {
        // If we're toggling sort on the same column, we simply toggle the direction. Otherwise, ASC it is.
        // e.SortDirection is useless and unreliable (only works with SQL data source).
        if (_sortBy == e.SortExpression)
            _sortDirection = _sortDirection == SortDirection.Descending ? SortDirection.Ascending : SortDirection.Descending;
        else
            _sortDirection = SortDirection.Ascending;

        _sortBy = e.SortExpression;

        BindResults();
    }

Answer 5

此问题不仅存在于SQL数据源中，也存在于对象数据源中。但是，在代码中动态设置DataSource时，就会发生这种情况。不幸的是，MSDN有时候信息非常糟糕。简单提一下这种行为（这不是一个bug，而是一个设计问题）可以节省大量时间。无论如何，我不太倾向于使用Session变量。我通常将排序方向存储在ViewState中。

Answer 6

我这样做的方式类似于accepted answer提供的代码，位有点不同所以我想我也会把它放在那里。请注意，在绑定到DataTable。DataSource之前，正在对GridView进行此排序。

选项一：使用ViewState

void DataGrid_Sorting(object sender, GridViewSortEventArgs e)
{
    if (e.SortExpression == (string)ViewState["SortColumn"])
    {
        // We are resorting the same column, so flip the sort direction
        e.SortDirection = 
            ((SortDirection)ViewState["SortColumnDirection"] == SortDirection.Ascending) ? 
            SortDirection.Descending : SortDirection.Ascending;
    }
    // Apply the sort
    this._data.DefaultView.Sort = e.SortExpression +
        (string)((e.SortDirection == SortDirection.Ascending) ? " ASC" : " DESC");
    ViewState["SortColumn"] = e.SortExpression;
    ViewState["SortColumnDirection"] = e.SortDirection;
}

选项二：使用会话

请注意，如果您在字段中看到以下内容，或者您​​仍然支持定位到较旧浏览器的公司系统，则会为传统目的提供以下内容。

void DataGrid_Sorting(object sender, GridViewSortEventArgs e)
{
    if (e.SortExpression == (string)HttpContext.Current.Session["SortColumn"])
    {
        // We are resorting the same column, so flip the sort direction
        e.SortDirection = 
            ((SortDirection)HttpContext.Current.Session["SortColumnDirection"] == SortDirection.Ascending) ? 
            SortDirection.Descending : SortDirection.Ascending;
    }
    // Apply the sort
    this._data.DefaultView.Sort = e.SortExpression +
        (string)((e.SortDirection == SortDirection.Ascending) ? " ASC" : " DESC");
    HttpContext.Current.Session["SortColumn"] = e.SortExpression;
    HttpContext.Current.Session["SortColumnDirection"] = e.SortDirection;
}

Answer 7

我不知道为什么每个人都忘记使用隐藏的字段！它们比ViewState（我自2005年以来关闭）“便宜”得多。如果您不想使用Session或ViewState，那么这是我的解决方案：

将这两个隐藏字段放在您的aspx页面上，并为您的数据设置所需的默认排序（例如我使用LastName）：

<asp:HiddenField ID="hfSortExpression" runat="server" Value="LastName" />
<asp:HiddenField ID="hfSortDirection" runat="server" Value="Ascending" />

然后将这个帮助程序代码放在你的Base页面中（你有一个基页不是吗？如果没有，请将你的.cs代码放在后面）。

/// <summary>
/// Since native ASP.Net GridViews do not provide accurate SortDirections, 
/// we must save a hidden field with previous sort Direction and Expression.
/// Put these two hidden fields on page and call this method in grid sorting event
/// </summary>
/// <param name="hfSortExpression">The hidden field on page that has the PREVIOUS column that is sorted on</param>
/// <param name="hfSortDirection">The hidden field on page that has the PREVIOUS sort direction</param>
protected SortDirection GetSortDirection(GridViewSortEventArgs e, HiddenField hfSortExpression, HiddenField hfSortDirection)
{
    //assume Ascending always by default!!
    SortDirection sortDirection = SortDirection.Ascending;

    //see what previous column (if any) was sorted on
    string previousSortExpression = hfSortExpression.Value;
    //see what previous sort direction was used
    SortDirection previousSortDirection = !string.IsNullOrEmpty(hfSortDirection.Value) ? ((SortDirection)Enum.Parse(typeof(SortDirection), hfSortDirection.Value)) : SortDirection.Ascending;

    //check if we are now sorting on same column
    if (e.SortExpression == previousSortExpression)
    {
        //check if previous direction was ascending
        if (previousSortDirection == SortDirection.Ascending)
        {
            //since column name matches but direction doesn't, 
            sortDirection = SortDirection.Descending;
        }
    }

    // save them back so you know for next time
    hfSortExpression.Value = e.SortExpression;
    hfSortDirection.Value = sortDirection.ToString();

    return sortDirection;
}

接下来，您需要在网格排序事件处理程序中处理排序。在调用获取数据的main方法之前，从排序事件处理程序中调用上面的方法

protected void gridContacts_Sorting(object sender, GridViewSortEventArgs e)
{
    //get the sort direction (since GridView sortDirection is not implemented!)
    SortDirection sortDirection = GetSortDirection(e, hfSortExpression, hfSortDirection);

    //get data, sort and rebind (obviously, this is my own method... you must replace with your own)
    GetCases(_accountId, e.SortExpression, sortDirection);
}

由于有很多例子使用DataTables或DataViews或其他非LINQ友好集合，我想我会包含一个调用中间层方法的示例，该方法返回一个通用列表，并使用LINQ按顺序进行排序完善示例并使其更“真实世界”：

private void GetCases(AccountID accountId, string sortExpression, SortDirection sortDirection)
{
    //get some data from a middle tier method (database etc._)(
    List<PendingCase> pendingCases = MyMiddleTier.GetCasesPending(accountId.Value);
    //show a count to the users on page (this is just nice to have)
    lblCountPendingCases.Text = pendingCases.Count.ToString();
    //do the actual sorting of your generic list of custom objects
    pendingCases = Sort(sortExpression, sortDirection, pendingCases);
    //bind your grid
    grid.DataSource = pendingCases;
    grid.DataBind();
}

最后，这是在自定义对象的通用列表上使用LINQ进行的向下和脏排序。我确信有更好的东西可以解决问题，但这说明了这个概念：

private static List Sort（string sortExpression，SortDirection sortDirection，List pendingCases）     {

    switch (sortExpression)
    {
        case "FirstName":
            pendingCases = sortDirection == SortDirection.Ascending ? pendingCases.OrderBy(c => c.FirstName).ToList() : pendingCases.OrderByDescending(c => c.FirstName).ToList();
            break;
        case "LastName":
            pendingCases = sortDirection == SortDirection.Ascending ? pendingCases.OrderBy(c => c.LastName).ToList() : pendingCases.OrderByDescending(c => c.LastName).ToList();
            break;
        case "Title":
            pendingCases = sortDirection == SortDirection.Ascending ? pendingCases.OrderBy(c => c.Title).ToList() : pendingCases.OrderByDescending(c => c.Title).ToList();
            break;
        case "AccountName":
            pendingCases = sortDirection == SortDirection.Ascending ? pendingCases.OrderBy(c => c.AccountName).ToList() : pendingCases.OrderByDescending(c => c.AccountName).ToList();
            break;
        case "CreatedByEmail":
            pendingCases = sortDirection == SortDirection.Ascending ? pendingCases.OrderBy(c => c.CreatedByEmail).ToList() : pendingCases.OrderByDescending(c => c.CreatedByEmail).ToList();
            break;
        default:
            break;
    }
    return pendingCases;
}

最后但并非最不重要（我已经说过了吗？）你可能想在你的Page_Load处理程序中放置这样的东西，以便网格在页面加载时默认绑定...注意_accountId是一个查询字符串参数，已转换在这种情况下，我自己的自定义帐户ID ...

    if (!Page.IsPostBack)
    {
        //sort by LastName ascending by default
        GetCases(_accountId,hfSortExpression.Value,SortDirection.Ascending);
    }

Answer 8

所有回答都不完全正确。我用那个：

protected void SetPageSort(GridViewSortEventArgs e) 
        { 
            if (e.SortExpression == SortExpression) 
            { 
                if (SortDirection == "ASC") 
                { 
                    SortDirection = "DESC"; 
                } 
                else 
                { 
                    SortDirection = "ASC"; 
                } 
            } 
            else 
            {
                if (SortDirection == "ASC")
                {
                    SortDirection = "DESC";
                }
                else
                {
                    SortDirection = "ASC";
                } 
                SortExpression = e.SortExpression; 
            } 
        } 
  protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
        {
            SetPageSort(e); 

在gridView_Sorting中

...

Answer 9

可以在不使用View State或Session的情况下完成。当前订单可以根据我们排序的列中第一行和最后一行的值来确定：

        protected void gvItems_Sorting(object sender, GridViewSortEventArgs e)
    {
        GridView grid = sender as GridView; // get reference to grid
        SortDirection currentSortDirection = SortDirection.Ascending; // default order

        // get column index by SortExpression
        int columnIndex = grid.Columns.IndexOf(grid.Columns.OfType<DataControlField>()
                                      .First(x => x.SortExpression == e.SortExpression));

        // sort only if grid has more than 1 row
        if (grid.Rows.Count > 1)
        {
            // get cells
            TableCell firstCell = grid.Rows[0].Cells[columnIndex];
            TableCell lastCell = grid.Rows[grid.Rows.Count - 1].Cells[columnIndex];

            // if field type of the cell is 'TemplateField' Text property is always empty.
            // Below assumes that value is binded to Label control in 'TemplateField'.
            string firstCellValue = firstCell.Controls.Count == 0 ? firstCell.Text : ((Label)firstCell.Controls[1]).Text;
            string lastCellValue = lastCell.Controls.Count == 0 ? lastCell.Text : ((Label)lastCell.Controls[1]).Text;

            DateTime tmpDate;
            decimal tmpDecimal;

            // try to determinate cell type to ensure correct ordering
            // by date or number
            if (DateTime.TryParse(firstCellValue, out tmpDate)) // sort as DateTime
            {
                currentSortDirection = 
                    DateTime.Compare(Convert.ToDateTime(firstCellValue), 
                                     Convert.ToDateTime(lastCellValue)) < 0 ? 
                                            SortDirection.Ascending : SortDirection.Descending;
            }
            else if (Decimal.TryParse(firstCellValue, out tmpDecimal)) // sort as any numeric type
            {
                currentSortDirection = Decimal.Compare(Convert.ToDecimal(firstCellValue), 
                                                       Convert.ToDecimal(lastCellValue)) < 0 ? 
                                                       SortDirection.Ascending : SortDirection.Descending;
            }
            else // sort as string
            {
                currentSortDirection = string.CompareOrdinal(firstCellValue, lastCellValue) < 0 ? 
                                                             SortDirection.Ascending : SortDirection.Descending;
            }
        }

        // then bind GridView using correct sorting direction (in this example I use Linq)
        if (currentSortDirection == SortDirection.Descending)
        {
            grid.DataSource = myItems.OrderBy(x => x.GetType().GetProperty(e.SortExpression).GetValue(x, null));
        }
        else
        {
            grid.DataSource = myItems.OrderByDescending(x => x.GetType().GetProperty(e.SortExpression).GetValue(x, null));
        }

        grid.DataBind();
    }

Answer 10

另一个:)不需要硬编码列名..

DataTable dt = GetData();

    SortDirection sd;
    string f;
    GridViewSortDirection(gvProductBreakdown, e, out sd, out f);
    dt.DefaultView.Sort = sd == SortDirection.Ascending ? f + " asc" : f + " desc";
    gvProductBreakdown.DataSource = dt;
    gvProductBreakdown.DataBind();

Ant然后：

 private void GridViewSortDirection(GridView g, GridViewSortEventArgs e, out SortDirection d, out string f)
    {
        f = e.SortExpression;
        d = e.SortDirection;
 if (g.Attributes[f] != null)
        {
            d = g.Attributes[f] == "ASC" ? SortDirection.Descending : SortDirection.Ascending;

            g.Attributes[f] = d == SortDirection.Ascending ? "ASC" : "DESC";
        }
        else
        {
            g.Attributes[f] = "ASC";
            d = SortDirection.Ascending;
        }

Answer 11

        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" AllowSorting="True" 
            onsorting="GridView1_Sorting" EnableViewState="true">
            <Columns><asp:BoundField DataField="bookid" HeaderText="BOOK ID" SortExpression="bookid"  />
                <asp:BoundField DataField="bookname" HeaderText="BOOK NAME" />
                <asp:BoundField DataField="writer" HeaderText="WRITER" />
                <asp:BoundField DataField="totalbook" HeaderText="TOTAL BOOK" SortExpression="totalbook"  />
                <asp:BoundField DataField="availablebook" HeaderText="AVAILABLE BOOK" />
//gridview code on page load under ispostback false//after that.



protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string query = "SELECT * FROM book";
            DataTable DT = new DataTable();
            SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
            DA.Fill(DT);


            GridView1.DataSource = DT;
            GridView1.DataBind();
        }
    }

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
    {

        string query = "SELECT * FROM book";
        DataTable DT = new DataTable();
        SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
        DA.Fill(DT);

        GridView1.DataSource = DT;
        GridView1.DataBind();

        if (DT != null)
        {

            DataView dataView = new DataView(DT);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);


            GridView1.DataSource = dataView;
            GridView1.DataBind();
        }
    }

    private string GridViewSortDirection
    {
        get { return ViewState["SortDirection"] as string ?? "DESC"; }
        set { ViewState["SortDirection"] = value; }
    }

    private string ConvertSortDirectionToSql(SortDirection sortDirection)
    {
        switch (GridViewSortDirection)
        {
            case "ASC":
                GridViewSortDirection = "DESC";
                break;

            case "DESC":
                GridViewSortDirection = "ASC";
                break;
        }

        return GridViewSortDirection;
    }
}

Answer 12

这可能会被押在这里，但我提出的解决方案对我的情况非常有用：

表单加载事件如下所示：

private DataTable DataTable1;
protected void Page_Load(object sender, EventArgs e)
{
  DataTable1 = GetDataFromDatabase();
  this.GridView1.DataSource = DataTable1.DefaultView;
  this.GridView1.DataBind();
}

在页面上添加两个隐藏字段：

<asp:HiddenField runat="server" ID="lastSortDirection" />
<asp:HiddenField runat="server" ID="lastSortExpression" />

将以下内容添加到您的asp：GridView对象：

AllowSorting="True" OnSorting="GridView1_Sorting"

使用以下GridView排序事件

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    if (lastSortExpression.Value == e.SortExpression.ToString())
    {
        if (lastSortDirection.Value == SortDirection.Ascending.ToString())
        {
            e.SortDirection = SortDirection.Descending;
        }
        else
        {
            e.SortDirection = SortDirection.Ascending;
        }
        lastSortDirection.Value = e.SortDirection.ToString();
        lastSortExpression.Value = e.SortExpression;
    }
    else
    {
        lastSortExpression.Value = e.SortExpression;
        e.SortDirection = SortDirection.Ascending;
        lastSortDirection.Value = e.SortDirection.ToString();
    }

    DataView dv = DataTable1.DefaultView;
    if (e.SortDirection == SortDirection.Ascending)
    {
        dv.Sort = e.SortExpression;
    }
    else
    {
        dv.Sort = e.SortExpression + " DESC";
    }

    DataTable1 = dv.ToTable();
    GridView1.DataSource = DataTable1.DefaultView;
    GridView1.DataBind();
}

现在，如果任何列发生更改，我的gridview中的每一列都会排序，而不需要任何进一步的更改。

Answer 13

我厌倦了处理这个问题并将排序方向和排序列放在ViewState ....

Answer 14

使用SecretSquirrel的solution above

这是我的全部工作，生产代码。只需将dgvCoaches更改为您的网格视图名称。

...在绑定网格期间

        dgvCoaches.DataSource = dsCoaches.Tables[0];
        ViewState["AllCoaches"] = dsCoaches.Tables[0];
        dgvCoaches.DataBind();

现在排序

protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
{
    DataTable dt = ViewState["AllCoaches"] as DataTable;

    if (dt != null)
    {
        if (e.SortExpression == (string)ViewState["SortColumn"])
        {
            // We are resorting the same column, so flip the sort direction
            e.SortDirection =
                ((SortDirection)ViewState["SortColumnDirection"] == SortDirection.Ascending) ?
                SortDirection.Descending : SortDirection.Ascending;
        }
        // Apply the sort
        dt.DefaultView.Sort = e.SortExpression +
            (string)((e.SortDirection == SortDirection.Ascending) ? " ASC" : " DESC");
        ViewState["SortColumn"] = e.SortExpression;
        ViewState["SortColumnDirection"] = e.SortDirection; 

        dgvCoaches.DataSource = dt;
        dgvCoaches.DataBind();
    }
}

这是aspx代码：

<asp:GridView ID="dgvCoaches" runat="server" 
    CssClass="table table-hover table-striped" GridLines="None"  DataKeyNames="HealthCoachID" OnRowCommand="dgvCoaches_RowCommand"
    AutoGenerateColumns="False" OnSorting="gridView_Sorting" AllowSorting="true">
    <Columns>
        <asp:BoundField DataField="HealthCoachID" Visible="false" />
        <asp:BoundField DataField="LastName" HeaderText="Last Name" SortExpression="LastName" />
        <asp:BoundField DataField="FirstName" HeaderText="First Name" SortExpression="FirstName" />
        <asp:BoundField DataField="LoginName" HeaderText="Login Name" SortExpression="LoginName" />
        <asp:BoundField DataField="Email" HeaderText="Email" SortExpression="Email" HtmlEncode="false" DataFormatString="<a href=mailto:{0}>{0}</a>" />
        <asp:TemplateField>
            <ItemTemplate>
                    <asp:LinkButton runat="server" BorderStyle="None" CssClass="btn btn-default" Text="<i class='glyphicon glyphicon-edit'></i>" CommandName="Update" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:LinkButton runat="server" OnClientClick="return ConfirmOnDelete();" BorderStyle="None" CssClass="btn btn-default" Text="<i class='glyphicon glyphicon-remove'></i>" CommandName="Delete" CommandArgument="<%# ((GridViewRow) Container).RowIndex %>" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    <RowStyle CssClass="cursor-pointer" />
</asp:GridView>

Answer 15

旧字符串，但也许我的答案会帮助某人。

首先将您的SqlDataSource作为DataView：

Private Sub DataGrid1_SortCommand(ByVal source As Object, ByVal e As DataGridSortCommandEventArgs) Handles grid1.SortCommand
    Dim dataView As DataView = CType(SqlDataSource1.Select(DataSourceSelectArguments.Empty), DataView)
    dataView.Sort = e.SortExpression + dataView.FieldSortDirection(Session, e.SortExpression)

    grid1.DataSourceID = Nothing
    grid1.DataSource = dataView
    grid1.DataBind()

End Sub

然后使用扩展方法进行排序（吱吱声的种类，但是一个良好的开端）：

public static class DataViewExtensions
{
    public static string FieldSortDirection(this DataView dataView, HttpSessionState session, string sortExpression)
    {
        const string SORT_DIRECTION = "SortDirection";
        var identifier = SORT_DIRECTION + sortExpression;

        if (session[identifier] != null)
        {
            if ((string) session[identifier] == " ASC")
                session[identifier] = " DESC";
            else if ((string) session[identifier] == " DESC")
                session[identifier] = " ASC";
        }
        else
            session[identifier] = " ASC";

        return (string) session[identifier];
    }
}

Answer 16

这是解决问题的另一种方法：

protected void grdHeader_OnSorting(object sender, GridViewSortEventArgs e)
{
    List<V_ReportPeriodStatusEntity> items = GetPeriodStatusesForScreenSelection();
    items.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e);
    grdHeader.DataSource = items;
    grdHeader.DataBind();
}

private string ConvertSortDirectionToSql(GridViewSortEventArgs e)
{
    ViewState[e.SortExpression] = ViewState[e.SortExpression] ?? "ASC";
    ViewState[e.SortExpression] = (ViewState[e.SortExpression].ToString() == "ASC") ? "DESC" : "ASC";
    return ViewState[e.SortExpression].ToString();
}

Answer 17

XML：

<asp:BoundField DataField="DealCRMID" HeaderText="Opportunity ID"
 SortExpression="DealCRMID"/>
<asp:BoundField DataField="DealCustomerName" HeaderText="Customer" 
 SortExpression="DealCustomerName"/>
<asp:BoundField DataField="SLCode" HeaderText="Practice" 
 SortExpression="SLCode"/>

代码：

private string ConvertSortDirectionToSql(String sortExpression,SortDirection sortDireciton)
{
    switch (sortExpression)
    {
        case "DealCRMID":
             ViewState["DealCRMID"]=ChangeSortDirection(ViewState["DealCRMID"].ToString());
             return ViewState["DealCRMID"].ToString();

        case "DealCustomerName":
             ViewState["DealCustomerName"] = ChangeSortDirection(ViewState["DealCustomerName"].ToString());
             return ViewState["DealCustomerName"].ToString();

        case "SLCode":
             ViewState["SLCode"] = ChangeSortDirection(ViewState["SLCode"].ToString());
             return ViewState["SLCode"].ToString();

        default:
            return "ASC";
    }       
}

private string ChangeSortDirection(string sortDireciton)
{
    switch (sortDireciton)
    {
        case "DESC":
            return "ASC";
        case "ASC":
            return "DESC";
        default:
            return "ASC";
    }
}

protected void gvPendingApprovals_Sorting(object sender, GridViewSortEventArgs e)
{
    DataSet ds = (System.Data.DataSet)(gvPendingApprovals.DataSource);

    if(ds.Tables.Count>0)
    {
        DataView m_DataView = new DataView(ds.Tables[0]);
        m_DataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql   (e.SortExpression.ToString(), e.SortDirection);

        gvPendingApprovals.DataSource = m_DataView;
        gvPendingApprovals.DataBind();
    }
}

Answer 18

要切换升序和降序，我在应用程序的BasePage中使用一个方法来缓存排序表达式和排序方向：

protected void SetPageSort(GridViewSortEventArgs e)
{
    if (e.SortExpression == SortExpression)
    {
        if (SortDirection == "ASC")
        {
            SortDirection = "DESC";
        }
        else
        {
            SortDirection = "ASC";
        }
    }
    else
    {
        SortDirection = "ASC";
        SortExpression = e.SortExpression;
    }
}

SortExpression和SortDirection都是BasePage中的属性，用于存储和从ViewState检索它们的值。

所以我的所有派生页面都只是从GridView的Sorting方法调用SetPageSort，并绑定GridView：

protected void gv_Sorting(object sender, GridViewSortEventArgs e)
{
    SetPageSort(e);
    BindGrid();
}

BindGrid检查SortExpression并使用它和SortDirection在网格的数据源上执行ORDERY BY，如下所示：

if (SortExpression.Length > 0)
{
    qry.ORDER_BY(SortExpression + " " + SortDirection);
}

gv.DataSource = qry.ExecuteReader();
gv.DataBind();

因此，基类'SetPageSort消除了GridView排序的大部分苦差事。我觉得我忘了什么，但那是一般的想法。

Answer 19

我使用GridView已经有一段时间了，但我认为你需要在离开OnSorting方法之前将网格的SortDirection属性设置为当前的状态。

...所以

List<V_ReportPeriodStatusEntity> items = GetPeriodStatusesForScreenSelection();
items.Sort(new Helpers.GenericComparer<V_ReportPeriodStatusEntity>(e.SortExpression, e.SortDirection));
的 grdHeader.SortDirection = e.SortDirection.Equals(SortDirection.Ascending) ? SortDirection.Descending : SortDirection.Ascending;
grdHeader.DataSource = items;
grdHeader.DataBind();

Answer 20

void dg_SortCommand(object source, DataGridSortCommandEventArgs e)
{
    DataGrid dg = (DataGrid) source;
    string sortField = dg.Attributes["sortField"];
    List < SubreportSummary > data = (List < SubreportSummary > ) dg.DataSource;
    string field = e.SortExpression.Split(' ')[0];
    string sort = "ASC";
    if (sortField != null)
    {
        sort = sortField.Split(' ')[0] == field ? (sortField.Split(' ')[1] == "DESC" ? "ASC" : "DESC") : "ASC";
    }
    dg.Attributes["sortField"] = field + " " + sort;
    data.Sort(new GenericComparer < SubreportSummary > (field, sort, null));
    dg.DataSource = data;
    dg.DataBind();
}

Answer 21

我遇到了一个可怕的问题所以我最终使用LINQ来命令DataTable，然后再将它分配给视图：

Dim lquery = From s In listToMap
             Select s
             Order By s.ACCT_Active Descending, s.ACCT_Name

特别是我在排序布尔字段时发现DataView.Sort和DataGrid.Sort方法不可靠。

我希望这可以帮助那些人。

Answer 22

也许这会对某人有所帮助。不知道是不是因为它是2014年，或者我不理解这篇文章试图解决的问题，但这对于slickgrid非常简单，如下所示：

问题似乎是如何记住＆＃39;当前的排序设置是什么，所以围绕Asp.Net的建议为您保留该值。但是，slickGrid可以告诉您当前的排序顺序是什么：

要切换排序asc desc，您可以使用grid.getSortColumns（）来查找当前列排序。这就是我所做的，但我一次只排序1列，因此我可以安全地执行此操作：＆＃39; if（grid.getSortColumns（）[0] .sortAsc）＆＃39;

...所以我的代码是这样的：

    // Make sure you have sortable: true on the relevant column names or 
    // nothing happens as I found!!
    var columns = [
    { name: "FileName", id: "FileName", field: "FileName", width: 95, selectable: true, sortable: true },
    { name: "Type", id: "DocumentType", field: "DocumentType", minWidth: 105, width: 120, maxWidth: 120, selectable: true, sortable: true },
    { name: "ScanDate", id: "ScanDate", field: "ScanDate", width: 90, selectable: true, sortable: true }, ];

..像往常一样加载数据，然后是排序部分：

   // Clicking on a column header fires this event. Here we toggle the sort direction
    grid.onHeaderClick.subscribe(function(e, args) {
        var columnID = args.column.id;

        if (grid.getSortColumns()[0].sortAsc) {
            grid.setSortColumn(args.column.id, true);
        }
        else {
            grid.setSortColumn(args.column.id, false);
        }
    });

    // The actual sort function is like this 
        grid.onSort.subscribe(function (e, args) {
            sortdir = args.sortAsc ? 1 : -1;
            sortcol = args.sortCol.field;

            //alert('in sort');

            // using native sort with comparer
            // preferred method but can be very slow in IE with huge datasets
            dataView.sort(comparer, args.sortAsc);
            grid.invalidateAllRows();
            grid.render();
        });

// Default comparer is enough for what I'm doing here ..
function comparer(a, b) {
    var x = a[sortcol], y = b[sortcol];
    return (x == y ? 0 : (x > y ? 1 : -1));
}

最后确保您的网站中包含SlickGrid图像文件夹，并且当您选择它时，您会在列上显示asc / desc箭头。如果它们丢失，文本将显示斜体，但不会出现箭头。

Answer 23

写这个，它对我有用：

 protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
    {
        if (ViewState["sortExpression"] == null || ViewState["sortExpression"].ToString() != e.SortExpression.ToString())
            MyDataTable.DefaultView.Sort = e.SortExpression + " ASC";
        else
        {
            if (ViewState["SortDirection"].ToString() == "Ascending")
                MyDataTable.DefaultView.Sort = e.SortExpression = e.SortExpression + " DESC";
            else
                MyDataTable.DefaultView.Sort = e.SortExpression + " ASC";
        }

        GridView1.DataSource = MyDataTable;
        GridView1.DataBind();

        ViewState["sortExpression"] = e.SortExpression;
        ViewState["SortDirection"] = e.SortDirection;
    }

Answer 24

这是我的工作方式。比这里的IMO要简单得多：

创建此SortDirection类

    // ==================================================
    // SortByDirection
    // ==================================================
    public SortDirection SortByDirection
    {
        get
        {
            if (ViewState["SortByDirection"] == null)
            {
                ViewState["SortByDirection"] = SortDirection.Ascending;
            }

            return (SortDirection)Enum.Parse(typeof(SortDirection), ViewState["SortByDirection"].ToString());
        }
        set { ViewState["SortByDirection"] = value; }
    }

然后像这样在您的排序函数中使用它：

            // Created Date
            if (sortBy == "CreatedDate")
            {
                if (SortByDirection == SortDirection.Ascending)
                {
                    data = data.OrderBy(x => x.CreatedDate).ToList();
                    SortByDirection = SortDirection.Descending;
                }
                else {
                    data = data.OrderByDescending(x => x.CreatedDate).ToList();
                    SortByDirection = SortDirection.Ascending;
                } 
            }

Answer 25

post('/action-route' , check() , check(), check() , (req,res) =>{
const errors = validationResult(req);
        if (!errors.isEmpty()) {
            res.json({ errors: errors.array()  });
        } else {
            res.json(req.body);
        }
});

，然后存储以前检索到的信息

protected void gv_Sorting(object sender, GridViewSortEventArgs e)
{
    DataTable dataTable = (DataTable)Cache["GridData"];

    if (dataTable != null)
    {
        DataView dataView = new DataView(dataTable);
        string Field1 = e.SortExpression;
        string whichWay = "ASC";
        if (HttpContext.Current.Session[Field1] != null)
        {
            whichWay = HttpContext.Current.Session[Field1].ToString();
            if (whichWay == "ASC")
                whichWay = "DESC";
            else
                whichWay = "ASC";               
        }

        HttpContext.Current.Session[Field1] = whichWay;
        dataView.Sort = Field1 + " " + whichWay;      
        gv.DataSource = dataView;
        gv.DataBind();
    }
}

Answer 26

在vb.net中但非常简单！

Protected Sub grTicketHistory_Sorting(sender As Object, e As GridViewSortEventArgs) Handles grTicketHistory.Sorting

    Dim dt As DataTable = Session("historytable")
    If Session("SortDirection" & e.SortExpression) = "ASC" Then
        Session("SortDirection" & e.SortExpression) = "DESC"
    Else
        Session("SortDirection" & e.SortExpression) = "ASC"
    End If
    dt.DefaultView.Sort = e.SortExpression & " " & Session("SortDirection" & e.SortExpression)
    grTicketHistory.DataSource = dt
    grTicketHistory.DataBind()

End Sub