Asp.Net Control Issue During Pagination : The Official Microsoft ASP.NET Forums

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shafiqkr

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454 Points

372 Posts

Asp.Net Control Issue During Pagination

Mar 29, 2012 07:51 AM|LINK

Hi.

i have created my own pagination class and i want to apply it on my gridview...here is my code....all is working but when we change page mean NEXT/PRV etv then data do not change.only paging changes.data remains the same....here is my code

i have created a class and ascx control for data to display

code on display.ascx

<%@ Register TagPrefix="cc1" Namespace="ABC.Controls" %>

this is at the end of gridview

<cc1:Pager ID="resultsPager" runat="server" ControlToPage="gvResults" 
                            CurrentPageIndex="0" FirstImageUrl="" LastImageUrl="" 
                            Mode="FirstPreviousNextLast" NextImageUrl="" PageSize="5" PreviousImageUrl="" 
                            ShowPageNumbers="True">
                        </cc1:Pager>

and this code is on display.ascx.cs

protected  void Page_PreRender(object sender, EventArgs e)
    {
     if (!IsPostBack)
     {
            gvResults.DataSource = ObjectDataSource1.Select();
           
            gvResults.DataBind();
       }          
    }

where should i put this code?what to change in this code so that data also get changed when some one change the pages

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Edited by XIII on Mar 29, 2012 07:54 AM

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mm10

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6445 Points

1187 Posts

Re: Asp.Net Control Issue During Pagination

Mar 29, 2012 11:07 AM|LINK

You probably need to change the CurrentPageIndex property on your UserControl when a page link is clicked.

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superguppie

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Re: Asp.Net Control Issue During Pagination

Mar 29, 2012 11:45 AM|LINK

How does the pager interact with the GridView?

Superguppie.
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When all you've got is a Hammer, Every Problem looks like a Nail. Michael Swain.

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shafiqkr

Member

454 Points

372 Posts

Re: Asp.Net Control Issue During Pagination

Apr 01, 2012 07:57 AM|LINK

superguppie
How does the pager interact with the GridView?

here is the code

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

            _controlToPage = Parent.FindControl(_controlToPageName);
            if (_controlToPage == null)
                throw new Exception(string.Format("'{0}' is not a valid value for ControlToPage (The control does not exist).", _controlToPageName));

            if (
                    ! (
                        (_controlToPage.GetType().IsSubclassOf(typeof(BaseDataBoundControl)))
                        ||
                        (_controlToPage.GetType().IsSubclassOf(typeof(BaseDataList)))
                    )
                )
                throw new Exception("Works only for Controls deriving from BaseDataBoundControl or BaseDataList.");

            if (_controlToPage is BaseDataBoundControl)
                ((BaseDataBoundControl)_controlToPage).DataBinding += new EventHandler(ControlToPage_DataBinding);
            else if (_controlToPage is BaseDataList)
                ((BaseDataList)_controlToPage).DataBinding += new EventHandler(ControlToPage_DataBinding);
        }

        private void ControlToPage_DataBinding(object sender, EventArgs e)
        {
            ChildControlsCreated = false;

            object o = null;

            if (_controlToPage is BaseDataBoundControl)
                o = ((BaseDataBoundControl)_controlToPage).DataSource;
            else if (_controlToPage is BaseDataList)
                o = ((BaseDataList)_controlToPage).DataSource;

            IEnumerable enumerable;

            if (o.GetType().Name == typeof(DataTable).Name)
                enumerable = ((DataTable)o).DefaultView;
            else
                enumerable = (IEnumerable)o;

            _pagedDataSource = new PagedDataSource();
            _pagedDataSource.AllowPaging = true;
            _pagedDataSource.DataSource = enumerable;
            _pagedDataSource.PageSize = PageSize;
            _pagedDataSource.CurrentPageIndex = CurrentPageIndex;

            if (_controlToPage is BaseDataBoundControl)
                ((BaseDataBoundControl)_controlToPage).DataSource = _pagedDataSource;
            else if (_controlToPage is BaseDataList)
                ((BaseDataList)_controlToPage).DataSource = _pagedDataSource;
            
            TotalPages = _pagedDataSource.PageCount;

            Visible = (TotalPages > 0);
        }

The above code is from pager class.

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mm10

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1187 Posts

Re: Asp.Net Control Issue During Pagination

Apr 01, 2012 01:41 PM|LINK

Post the code for the NEXT/PRV events. I guess you have some linkbuttons or similar for each page with records. When you click a linkbutton, you need to change the CurrentPageIndex for the PagedDataSource that your control is bound to.

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shafiqkr

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454 Points

372 Posts

Re: Asp.Net Control Issue During Pagination

Apr 02, 2012 05:54 AM|LINK

mm10
Post the code for the NEXT/PRV events

This is the remaining code....

protected override void CreateChildControls()
        {
            _table.Rows.Clear();
            Controls.Clear();
            ClearChildViewState();

            //for Valid XHTML 1.0 Transitional the table-tag cannot be placed directly within span-tag
            //span-tag is created automatically by the .net control
            //HtmlGenericControl obj = new HtmlGenericControl("object");
            //Controls.Add(obj);

            Controls.Add(_table);
            //obj.Controls.Add(_table);
            _table.EnableViewState = false;
            _table.Width = Unit.Percentage(100);
            _table.Rows.Add(new TableRow());

            TableCell cell = null;

            cell = new TableCell();
            _table.Rows[0].Cells.Add(cell);
            cell.Width = Unit.Percentage(20);
            cell.HorizontalAlign = HorizontalAlign.Left;

            // first button
            if ((CurrentPageIndex > 0) && ((Mode == PagerMode.FirstLast) || (Mode == PagerMode.FirstPreviousNextLast)))
            {
                LinkButton btn = new LinkButton();
                cell.Controls.Add(btn);
                if (FirstImageUrl != string.Empty)
                    btn.Text = string.Format("<img src=\"{0}\" border=\"0\" alt=\"\" />", FirstImageUrl);
                else
                    btn.Text = "|&lt;&lt;";
                btn.CommandArgument = "0";
                btn.CommandName = "Page";
                btn.Command += new CommandEventHandler(btn_Command);
                btn.CausesValidation = false;
            }

            // previous button
            if ((CurrentPageIndex > 0) && ((Mode == PagerMode.PreviousNext) || (Mode == PagerMode.FirstPreviousNextLast)))
            {
                if (cell.Controls.Count > 0)
                {
                    Literal lit = new Literal();
                    lit.Text = "&nbsp;";
                    cell.Controls.Add(lit);
                }

                LinkButton btn = new LinkButton();
                cell.Controls.Add(btn);
                if (PreviousImageUrl != string.Empty)
                    btn.Text = string.Format("<img src=\"{0}\" border=\"0\" alt=\"\" />", PreviousImageUrl);
                else
                    btn.Text = "&lt;";
                btn.CommandArgument = (CurrentPageIndex - 1).ToString();
                btn.CommandName = "Page";
                btn.Command += new CommandEventHandler(btn_Command);
                btn.CausesValidation = false;
            }

            // page numbers
            cell = new TableCell();
            _table.Rows[0].Cells.Add(cell);
            cell.HorizontalAlign = HorizontalAlign.Center;
            cell.Width = Unit.Percentage(40);

            if (_showPageNumbers)
            {
                for (int i = 0; i < TotalPages; i++)
                {
                    if (cell.Controls.Count > 0)
                    {
                        Literal lit = new Literal();
                        lit.Text = "&nbsp;";
                        cell.Controls.Add(lit);
                    }

                    if (i != CurrentPageIndex)
                    {
                        LinkButton btn = new LinkButton();
                        cell.Controls.Add(btn);
                        //this is shafiq coding for ....
                        // int cT = CurrentPageIndex + 3;
                        // int cW = CurrentPageIndex + 7;
                        // if (cW > i)
                        // {
                        // if (cT < i)
                        // {
                        //  btn.Text = "..";
                        //}
                        // else
                        // {
                        // btn.Text = (i + 1).ToString();
                        //}
                        btn.Text = (i + 1).ToString();
                        btn.CommandName = "Page";
                        btn.CommandArgument = i.ToString();
                        btn.Command += new CommandEventHandler(btn_Command);
                        btn.CausesValidation = false;
                    }
                    else
                    {
                        Literal lit = new Literal();
                        cell.Controls.Add(lit);
                        lit.Text = (i + 1).ToString();
                    }
                }
            }

            cell = new TableCell();
            _table.Rows[0].Cells.Add(cell);
            cell.Width = Unit.Percentage(20);
            cell.HorizontalAlign = HorizontalAlign.Right;

            // next button
            if ((CurrentPageIndex < TotalPages - 1) && ((Mode == PagerMode.PreviousNext) || (Mode == PagerMode.FirstPreviousNextLast)))
            {
                LinkButton btn = new LinkButton();
                cell.Controls.Add(btn);
                if (NextImageUrl != string.Empty)
                    btn.Text = string.Format("<img src=\"{0}\" border=\"0\" alt=\"\" />", NextImageUrl);
                else
                    btn.Text = "&gt;";
                btn.CommandArgument = (CurrentPageIndex + 1).ToString();
                btn.CommandName = "Page";
                btn.Command += new CommandEventHandler(btn_Command);
                btn.CausesValidation = false;
            }

            // last button
            if ((CurrentPageIndex < TotalPages - 1) && ((Mode == PagerMode.FirstLast) || (Mode == PagerMode.FirstPreviousNextLast)))
            {
                if (cell.Controls.Count > 0)
                {
                    Literal lit = new Literal();
                    lit.Text = "&nbsp;";
                    cell.Controls.Add(lit);
                }

                LinkButton btn = new LinkButton();
                cell.Controls.Add(btn);
                if (LastImageUrl != string.Empty)
                    btn.Text = string.Format("<img src=\"{0}\" border=\"0\" alt=\"\" />", LastImageUrl);
                else
                    btn.Text = "&gt;&gt;|";
                btn.CommandArgument = (TotalPages - 1).ToString();
                btn.CommandName = "Page";
                btn.Command += new CommandEventHandler(btn_Command);
                btn.CausesValidation = false;
            }
        }

        void btn_Command(object sender, CommandEventArgs e)
        {
            CurrentPageIndex = int.Parse(e.CommandArgument.ToString());
        }
    }

    public enum PagerMode
    {
        FirstLast,
        PreviousNext,
        FirstPreviousNextLast,
        None
    }

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mm10

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6445 Points

1187 Posts

Re: Asp.Net Control Issue During Pagination

Apr 02, 2012 07:10 AM|LINK

You need to databind the control in the btn_Command event handler:

void btn_Command(object sender, CommandEventArgs e)
        {
            CurrentPageIndex = int.Parse(e.CommandArgument.ToString());

_pagedDataSource = new PagedDataSource(); 
            _pagedDataSource.AllowPaging = true; 
            _pagedDataSource.DataSource = enumerable; 
            _pagedDataSource.PageSize = PageSize; 
            _pagedDataSource.CurrentPageIndex = CurrentPageIndex;

YourControl.DataSource = _pagedDataSource;
YourControl.DataBind();
        }

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Edited by mm10 on Apr 02, 2012 07:12 AM

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shafiqkr

Member

454 Points

372 Posts

Re: Asp.Net Control Issue During Pagination

Apr 02, 2012 09:05 AM|LINK

mm10
You need to databind the control in the btn_Command event handler:

Using your code enumerable is not define in your code..so i made it again like i have in my first code so finally i made it like this

void btn_Command(object sender, CommandEventArgs e)
        {

 CurrentPageIndex = int.Parse(e.CommandArgument.ToString());
          
            if (_controlToPage is BaseDataBoundControl)
                ((BaseDataBoundControl)_controlToPage).DataBinding += new EventHandler(ControlToPage_DataBinding);
            else if (_controlToPage is BaseDataList)
                ((BaseDataList)_controlToPage).DataBinding += new EventHandler(ControlToPage_DataBinding);
            object o = null;

            if (_controlToPage is BaseDataBoundControl)
                o = ((BaseDataBoundControl)_controlToPage).DataSource;
            else if (_controlToPage is BaseDataList)
                o = ((BaseDataList)_controlToPage).DataSource;

            IEnumerable enumerable;

            
                enumerable = (IEnumerable)o;
            _pagedDataSource = new PagedDataSource();
            _pagedDataSource.AllowPaging = true;
            _pagedDataSource.DataSource = enumerable;
            _pagedDataSource.PageSize = PageSize;
            _pagedDataSource.CurrentPageIndex = CurrentPageIndex;
            if (_controlToPage is BaseDataBoundControl)
                ((BaseDataBoundControl)_controlToPage).DataSource = _pagedDataSource;
            else if (_controlToPage is BaseDataList)
                ((BaseDataList)_controlToPage).DataSource = _pagedDataSource;
            ((BaseDataList)_controlToPage).DataBind();

}

Now on debugging Datasource(Bold one) is NULL after click next page.so O si null..so not working

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Edited by shafiqkr on Apr 02, 2012 09:06 AM

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mm10

Contributor

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1187 Posts

Re: Asp.Net Control Issue During Pagination

Apr 02, 2012 10:50 AM|LINK

On which line is the datasource NULL?

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superguppie

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48225 Points

8679 Posts

Re: Asp.Net Control Issue During Pagination

Apr 02, 2012 02:33 PM|LINK

On PostBack the DataSource is not remembered. You need to get it again, just like a regular DataBind.

Superguppie.
Please remember to click “Mark as Answer” on the post that helps you. This can be beneficial to other community members reading the thread.
When all you've got is a Hammer, Every Problem looks like a Nail. Michael Swain.

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shafiqkr

Asp.Net Control Issue During Pagination

mm10

Re: Asp.Net Control Issue During Pagination

superguppie

Re: Asp.Net Control Issue During Pagination

shafiqkr

Re: Asp.Net Control Issue During Pagination

superguppie

mm10

Re: Asp.Net Control Issue During Pagination

shafiqkr

Re: Asp.Net Control Issue During Pagination

mm10

mm10

Re: Asp.Net Control Issue During Pagination

shafiqkr

Re: Asp.Net Control Issue During Pagination

mm10

mm10

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superguppie

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