在gridView中分页时如何保持排序顺序
本文关键字:何保持 排序 顺序 gridView 分页 | 更新日期: 2023-09-27 18:27:35
我使用gridView显示信息。除了一个细节外,它对我来说绝对完美。如果用户对一列进行排序,然后单击转到另一页,则排序将丢失。基本上,我需要在分页发生时保持排序,任何帮助都将不胜感激。这是我的代码:
public partial class DynamicGridView : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
if (_selectCmd != string.Empty)
BindData();
}
private void BindData()
{
DataTable dt;
if (ViewState[gridView.ClientID + "datatable"] == null || (string)ViewState[gridView.ClientID + "selectCommand"] != _selectCmd)
{
ViewState[gridView.ClientID + "selectCommand"] = _selectCmd;
dt = Classes.SQL.GetDataTable(_selectCmd);
if (dt != null)
{
ViewState[gridView.ClientID + "datatable"] = dt;
if (dt.Columns.Count != gridView.Columns.Count)
{
gridView.Columns.Clear();
foreach (DataColumn column in dt.Columns)
AddBoundField(column);
}
}
}
else
dt = (DataTable)ViewState[gridView.ClientID + "datatable"];
gridView.DataSource = dt;
gridView.DataBind();
}
private void AddBoundField(DataColumn column)
{
BoundField field = new BoundField();
HandleCustomDataFormatting(ref field, column);
field.DataField = column.ColumnName;
field.HeaderText = column.ColumnName;
field.ReadOnly = true;
field.SortExpression = column.ColumnName;
field.ControlStyle.ForeColor = System.Drawing.ColorTranslator.FromHtml("#333333");
field.ItemStyle.Width = System.Web.UI.WebControls.Unit.Pixel(70);
gridView.Columns.Add(field);
}
private void HandleCustomDataFormatting(ref BoundField field, DataColumn column)
{
if (column.DataType == typeof(System.DateTime))
switch (column.ColumnName)
{
case "InvalidDate":
case "NewCustomerValidated":
case "ValidatedDate":
field.DataFormatString = "{0:d}";//exclude time info
break;
default:
field.DataFormatString = "{0:g}";
break;
}
}
private string GetSortDirection(string sortColumn)
{
string sortDirection = "ASC";
string lastSortColumn = (string)ViewState[gridView.ClientID + "SortExpression"];
if (lastSortColumn != null && lastSortColumn == sortColumn)
{
string lastDirection = (string)ViewState[gridView.ClientID + "SortDirection"];
if (lastDirection != null && lastDirection == "ASC")
sortDirection = "DESC";
}
ViewState[gridView.ClientID + "SortExpression"] = sortColumn;
ViewState[gridView.ClientID + "SortDirection"] = sortDirection;
return sortDirection;
}
private string _selectCmd = string.Empty;
public string SelectCommand
{
set { _selectCmd = value; }
}
protected void GridView_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable dt = (DataTable)ViewState[gridView.ClientID + "datatable"];
dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression);
BindData();
}
protected void GridView_PageChange(object sender, GridViewPageEventArgs e)
{
gridView.PageIndex = e.NewPageIndex;
BindData();
}
}
您不需要在每次页面加载时绑定。
if (_selectCmd != string.Empty)
if(!IsPostBack)
BindData();
此外,要小心在ViewState中放入的内容,放入sql查询不是一个好的做法。
这种方法对我很有效。
你可以设置几个变量如下:
protected string SortColummn
{
get { return ViewState["SortColumn"].ToString(); }
set { ViewState["SortColumn"] = value; }
}
protected string SortDirection
{
get { return ViewState["SortDirection"].ToString(); }
set { ViewState["SortDirection"] = value; }
}
在"if(!Page.IsPostBack)"块的Page_Load中为这些设置默认值。然后,在GridView_Sorting中,根据e.SortExpression设置这两个变量。最后,在BindData()中,设置dt。DefaultView.根据这两个变量进行排序。