在asp.net中对gridview列进行排序

Question

我有一个从数据库加载数据的网格视图。数据首次显示在网格视图中，按日期时间排序。在该 gridview 的一列上，我想允许排序，例如在 main_post 列上。我已经尝试过这个，但是当我单击列标题时，gridview 仍然没有排序。

这是我的 gridview 前端代码：

<asp:DataGrid ID="Datagrid1" runat="server" 
    AllowPaging="True" 
    AllowSorting="True" 
    OnSorting="ComponentGridView_Sorting">
    <Columns>
        <asp:BoundColumn DataField="main_post" HeaderText="Header Post ID" 
            SortExpression="ComponentGridView_Sorting" />
    </Columns>
</asp:DataGrid>

我的后端代码：

protected void loadData()
{
    DataTable dtTemp;
    dtTemp = objDBInterface.getResults(strSQL);
    Datagrid1.DataSource = dtTemp;
    Datagrid1.DataBind();
    ViewState["dtbl"] = dtTemp;
}

protected void ComponentGridView_Sorting(object sender, GridViewSortEventArgs e)
    {
        DataTable dataTable = ViewState["dtbl"] as DataTable;
        if (dataTable != null)
        {
            DataView dataView = new DataView(dataTable);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirection(e.SortDirection);
            Datagrid1.DataSource = dataView;
            Datagrid1.DataBind();
        }
    }
    private string ConvertSortDirection(SortDirection sortDirection)
    {
        string newSortDirection = String.Empty;
        switch (sortDirection)
        {
            case SortDirection.Ascending:
                newSortDirection = "ASC";
                break;
            case SortDirection.Descending:
                newSortDirection = "DESC";
                break;
        }

        return newSortDirection;
    }

我没有任何错误，我不知道我的错误在哪里，有人可以帮我解决这个问题吗？

提前致谢。

Answer 1

很简单，将Allowsorting属性设置为true并在gridview中添加排序事件。

<asp:GridView ID="GridView1" runat="server" AllowSorting="true" 
      OnSorting="GridView1_Sorting">
</asp:GridView>   

现在在 .cs 文件中添加事件 OnSorting

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{ 
    SetSortDirection(SortDireaction);
    if (dataTable != null)
    {
       dataTable.DefaultView.Sort = e.SortExpression + " " +_sortDirection;
        GridView1.DataSource = dataTable;
        GridView1.DataBind();
        SortDireaction = _sortDirection;
    }
} 
protected void SetSortDirection(string sortDirection)
{
    if (sortDirection == "ASC")
    {
        _sortDirection = "DESC";
    }
    else
    {
        _sortDirection = "ASC";
    }
} 

Answer 2

我得到了解决方案。希望这能帮助其他面临类似问题的人。在.aspx页面上需要更改：

从OnSorting="ComponentGridView_Sorting"

到onsortcommand="ComponentGridView_Sorting"

然后将这段代码放在aspx.cs（后端代码）上：

protected void Datagrid1_SortCommand(object source, DataGridSortCommandEventArgs e)
    {
        string strSQL;
        DataTable dt;
        strSQL = "YOUR SELECT STATEMENT (SQL)";
        dt = strSQL;
            {
                string SortDir = string.Empty;
                if (dir == SortDirection.Ascending)
                {
                    dir = SortDirection.Descending;
                    SortDir = "Desc";
                }
                else
                {
                    dir = SortDirection.Ascending;
                    SortDir = "Asc";
                }
                DataView sortedView = new DataView(dt);
                sortedView.Sort = e.SortExpression + " " + SortDir;
                Datagrid1.DataSource = sortedView;
                Datagrid1.DataBind();
            }
    }

    protected SortDirection dir
    {
        get
        {
            if (ViewState["dirState"] == null)
            {
                ViewState["dirState"] = SortDirection.Ascending;
            }
            return (SortDirection)ViewState["dirState"];
        }
        set
        {
            ViewState["dirState"] = value;
        }
    }