Problem with selected Rows Grid (loosing State)

[David]

Hello Guys,

i testet some of the functions of your Rad Grid, i can not add the Grid or the Columns
via design mode, they are dynamical added  serverside.
I checked all the Samples that you wrote but can find nothing that fits to my situation.

Sorting stays enabled, but the selected Rows are gone through paging.


Code in ascx

<telerik:RadAjaxPanel ID="_panFilec" runat="server" Height="188px"
    Width="90%" LoadingPanelID="_fileconloadpan" oninit="RadAjaxPanel1_Init" Visible="false" >
<telerik:RadAjaxLoadingPanel ID="_fileconloadpan" runat="server" Height="75px"
            Width="75px" Transparency="30">
<img src="/_layouts/images/myTestloader.gif" alt="Loading..." style="border: 0; margin-top: 45px; color:Black;"/>
</telerik:RadAjaxLoadingPanel>
    </telerik:RadAjaxPanel>

Code for Grid:

public partial class TestWebControl : System.Web.UI.UserControl
    {
        private const string _LOADINGSOURCE = "/_controltemplates/TestWebControl.ascx";
        private const string _VIEWSTATEITEMID = "VIEWSTATEITEMID";
        private const string _DATASOURCECACHE = "_DATASORCECACHE";

        private ICachingOperations _caching;
        private ITelerikBehavior _telerikbehavior;
        private ISearchBehavior _search;

        private RadGrid _gridViewContent;
        private List<GridColumn> _columns;

        public List<GridColumn> Columns
        {
            get
            {
                 return this._columns;
            }
            set
            {
                this._columns= value;
            }
        }
        private string _lastchacheDependency;

        private string _chacheDependency;

        public string CacheDependency
        {
            get { return _chacheDependency; }
            set { _chacheDependency = value; }
        }

        public ISearchBehavior Search
        {
            get { return _search; }
            set { _search = value; }
        }

        private bool _enableSelectColumn = true;

        public bool EnableSelectColumn
        {
            get { return _enableSelectColumn ; }
            set { _enableSelectColumn = value; }
        }


        public ITelerikBehavior Telerikbehavior
        {
            get
            {
                if (_telerikbehavior != null)
                { return _telerikbehavior; }
                else
                {
                    this._telerikbehavior = new TestTelerikBehavior();
                    return _telerikbehavior;
                }
            }
            set
            {
                if (_telerikbehavior != null)
                {
                    _telerikbehavior = value;
                }
            }
        }

        public ICachingOperations Caching
        {
            get {

                if(_caching!=null)
                {return _caching;}

                else
                {
                    this._caching = new ControlToSession(this.ID);
                    return _caching;
                }
            }
            set
            {
                if (value != null)
                {_caching = value;}
            }
        }

        public static TestWebControl LoadFileContent(Page page)
        {
            return page.LoadControl(_LOADINGSOURCE) as FileContentWebControl;
        }

        private int pageSize = 5;
        /// <summary>
        /// Gets or sets the number of items to show per page
        /// </summary>
        public int PageSize
        {
            get { return pageSize; }
            set { pageSize = value; }
        }

        //public void ResetColumns(List<GridColumn> columns)
        //{

        //
        //}

        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);



            _gridViewContent = new RadGrid();
            _gridViewContent.AutoGenerateColumns = false;
            _gridViewContent.Attributes.Add("Width", "80%");
            _gridViewContent.AllowPaging = true;
            _gridViewContent.PageSize = this.PageSize;
            _gridViewContent.AllowSorting = true;
            _gridViewContent.AllowMultiRowSelection = true;
            _gridViewContent.PagerStyle.Mode=GridPagerMode.NextPrev;
            //_gridViewContent.ClientSettings.AllowDragToGroup = true;
            _gridViewContent.ClientSettings.EnableRowHoverStyle = true;
            _gridViewContent.ClientSettings.EnablePostBackOnRowClick = true;
            //_gridViewContent.ClientSettings.Selecting.AllowRowSelect = true;
            //_gridViewContent.ItemCreated += new GridItemEventHandler(_gridViewContent_ItemCreated);
            _gridViewContent.Skin = this.Telerikbehavior.TelerikSkin;
            //_gridViewContent.EnableViewState = false;
            _gridViewContent.NeedDataSource+=new GridNeedDataSourceEventHandler(_gridViewContent_NeedDataSource);
        }

        void _gridViewContent_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
        {
            if (!string.IsNullOrEmpty(_chacheDependency) && Columns != null)
            {

                DataTable datssource = getData();
                if (source != null && datssource.Rows.Count > 0)
                {

                  _gridViewContent.DataSource = datssource;

                }
                else
                {
                    _gridViewContent.DataSource = null;
                }
            }
            else
            {
                _gridViewContent.DataSource = null;
            }
        }

        //void _gridViewContent_ItemCreated(object sender, GridItemEventArgs e)
        //{

        //    if (e.Item is GridDataItem)
        //    {
        //        e.Item.PreRender += new EventHandler(Item_PreRender);
        //    }
        //}

        //void Item_PreRender(object sender, EventArgs e)
        //{
        //    ((sender as GridDataItem)["CheckBoxTemplateColumn"].FindControl("IMGchbx") as CheckBox).Checked = (sender as GridDataItem).Selected;
        //}

        protected void RadAjaxPanel1_Init(object sender, EventArgs e)
        {

        }

        protected override void CreateChildControls()
        {
            base.CreateChildControls();
            string traceConst = _TRACECONST + "CreateChildControls()";
            ECSpand.Logging.Log.WriteDebug("Entering", traceConst);


              if (Columns != null)
              {
                  if (_enableSelectColumn )
                  {
                      TESTCHBoxColumn columnun = new TESTCHBoxColumn();
                      columnun.UniqueName = "CheckBoxTemplateColumn";
                      _gridViewContent.MasterTableView.Columns.Add(columnun);

                  }

                  //_gridViewContent.Columns.Clear();
                  Columns.ForEach(o => _gridViewContent.Columns.Add(o));
              }

            if (ViewState[_VIEWSTATEITEMID] != null)
                _lastchacheDependency = (ViewState[_VIEWSTATEITEMID] as string);

            _panFilec.Controls.Add(_gridViewContent);
        }

        protected override void OnPreRender(System.EventArgs e)
        {
              if (!string.IsNullOrEmpty(_chacheDependency) && Columns !=null)
            {
                DataTable source = getData();
                if (source !=null && source.Rows.Count > 0)
                {
                    _gridViewContent.DataSource = source;
                    if (ItemChanged())
                    {
                        _gridViewContent.Rebind();
                    }
                    _panFilec.Visible = true;
                }
                else
                { _gridViewContent.Rebind(); }

                ViewState[_VIEWSTATEITEMID] = this._chacheDependency;
            }
            else
            {
                _gridViewContent.Rebind();
                ViewState[_VIEWSTATEITEMID] = null;
            }


        }

        public void ResetGridView()
        {
            if (_gridViewContent != null)
            {
                //_gridViewContent.DataSource = null;
                this._chacheDependency = null;
                _gridViewContent.Rebind();
                _panFilec.Controls.Clear();
                _panFilec.Visible = false;
                this.Caching.RemoveObjectFromSession(_DATASOURCECACHE);
            }
        }

        private DataTable getData()
        {

            if (ItemChanged()&& Search!=null)
            {
                DataTable table = this.Search.PerformSearch();
                this.Caching.SaveObjectToSession(_DATASOURCECACHE, table);
                return table;
            }

            else
            {
                return this.Caching.GetObjectFromSession(_DATASOURCECACHE) as DataTable;
            }
        }


        protected override void Render(HtmlTextWriter writer)
        {

            _panFilec.RenderControl(writer);

        }

        /// <summary>
        /// Checks, if a different item is displayed
        /// </summary>
        /// <returns></returns>
        bool ItemChanged()
        {
            return !(_chacheDependency.CompareTo(_lastchacheDependency)==0);
        }

    }
}

Code for Column Template:

  public class TESTCHBoxColumn: GridTemplateColumn
    {
        public TESTCHBoxColumn()
        {
            ISImageButtonTemplate btntemplate = new ISImageButtonTemplate();
            ISImageCheckBox chbxtempalte = new ISImageCheckBox();

            this.HeaderTemplate = btntemplate;
            this.ItemTemplate = chbxtempalte;
        }
    }

 public class ISImageButtonTemplate : System.Web.UI.ITemplate
    {
        #region ITemplate Members
        private const string _CHECKATT = "CHECKATT";
        ImageButton _btn;

        public ISImageButtonTemplate()
        {
            _btn = new ImageButton();
            _btn.ID = "ISImgBtn";
            _btn.ImageUrl = "/_layouts/images/niceTestpic.png";
            _btn.Click += new System.Web.UI.ImageClickEventHandler(_btn_Click);
            _btn.Attributes.Add(_CHECKATT, "false");
        }

        public void InstantiateIn(System.Web.UI.Control container)
        {
            container.Controls.Add(_btn);
        }

        void _btn_Click(object sender, System.Web.UI.ImageClickEventArgs e)
        {
            ImageButton imgbtn = sender as ImageButton;
            RadGrid grid = imgbtn.Parent.Parent.Parent.Parent.Parent.Parent as RadGrid;
            if (grid != null)
            {
                bool check = !My.ConversionHelper.StringToBool(imgbtn.Attributes[_CHECKATT] as string);

                foreach (GridDataItem dataItem in grid.Items)
                {
                    (dataItem.FindControl("IMGchbx") as CheckBox).Checked = check;
                    dataItem.Selected = check;
                }
                imgbtn.Attributes[_CHECKATT] = (check).ToString();
            }

        }
    }

  public class ISImageCheckBox :System.Web.UI.ITemplate
    {

       private CheckBox _box;
       private int number = 0;

        public ISImageCheckBox()
        {
            number = 0;
        }

        public void InstantiateIn(System.Web.UI.Control container)
        {
            number++;
            _box = new CheckBox();
            _box.AutoPostBack = true;
            _box.ID = "IMGchbx";
            _box.CheckedChanged += new EventHandler(_box_CheckedChanged);

            container.Controls.Add(_box);
        }

          void _box_CheckedChanged(object sender, EventArgs e)
        {
            ((sender as CheckBox).Parent.Parent as GridItem).Selected = (sender as CheckBox).Checked;
        }


    }

[Dimo]

Hello David,

Indeed, selection is not persisted across paging. Please refer to the following help article to see how to preserve the selected rows:

http://www.telerik.com/help/aspnet-ajax/grdpersistselectedrowsonsorting.html

Best wishes,
Dimo
the Telerik team

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[David]

Thank you for your Reply,
that it, thank you !