Pagination & Sorting as Usercontrol

Pagination & Sorting in User control

It is a control used to move to any pages that we need .We can set the page size of the grid using this control. We can sort any column in ascending and descending order by just clicking corresponding heading with this control. Using this control users can move to the first and last page with just a button click. It also displays the total records and total number of pages available with respect to the given page size.

Features

1. Immediate page navigation

   If we change the value in the text box within the limit of the pages available it will call the event defined in code behind of aspx page for user control . Event in the code behind of aspx page will call the stored procedure to bind the listview.

2. Define Records count / page

   If we change the drop down value then it will call the event defined in code behind of aspx page for user control . Event in the code behind of aspx page will call the stored procedure to bind the list view.

3. Sort ascending or descending based on any of the field in list view by just clicking on heading.

   On clicking the heading the method defined in user control will be called ,and it will hide other images in the list view header and , call back the aspx page method with current column name and order as parameter . Method in the aspx page will call the stored procedure to bind the list view and make the corresponding image visible.

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4. Navigate to last and first page with a button click.

   With the click of the First Page it will send the page number as 1 .It will set the value of text box as the same. It will call the event defined in the code behind page of aspx page for user control . Event in the code behind of aspx page will call the stored procedure to bind the list view. With the click of the Last Page it will sent the page number as the maximum number of pages available. It will set the value of text box as the same. It will call the event defined in code behind of aspx page for user control. Event in the code behind of aspx page will call the stored procedure to bind the list view.

5. Displays the total records

   When the page loads the user control will bind the value of the total records from the database by calling the method defined in aspx page with the page number specified in the text box as parameter from the user control . Method in the aspx page will call the stored procedure to bind the list view.

Stored Procedure

Create a Stored Procedure for each page for Selecting the needed columns in the List View with the parameters page number,page size, column name & order to which we need to apply sorting and the order in which we need to get it sorted (ascending or descending).

User Control

Make the above table as user control design. Define the functions and events. Inherit the interface that we created in Abstract class. To call the function from the user control we must use the following code in code behind of user control.

// write code here
AbstractClass page=(AbstractClass)Page;
page.ListGridview(CurrentPage,PageSize,SortOrder);

Register the user control in the top of the aspx page where we add pagination.

// write code here
<%@ Register src="~/Paging.ascx" TagName="page" TagPrefix="uc1"%>

<uc1:page ID="pageGrid" runat="server" Visible="true"/>

<asp:LinkButton ID="lnkCode" ToolTip="Click to sort" CssClass="lnkFont" CommandName="btnSortCode" CommandArgument="Code" runat="server">Route Code</asp:LinkButton>


<img src="~/Images/Down_Arrow.jpg" id="btnSortCode" runat="server" />

Code Behind

Method to bind grid should be over ridden from code behind. Call List View's Item Command event for sorting .

protected void lvRoute_ItemCommand(object sender,ListViewCommandEventArgs e)
{}

Inside this event we can call the functions that we declare in User Control. For that we should give usercontrolId.HideArrows() and usercontrolId.SortRecords().For Paging we should call the user control event Pager_Changed which is defined in User control.

protected void Pager_Changed(object sender,PagerEventArgs e)
{
var pageNumber=e.PageNumber;
var pageSize=e.PageSize;
ListGridview(pageNumber,pageSize,hdnSortOrder.Value);
}

Abstract Class

Create an abstract class in the App Code to create an abstract method to call this method from user control & to give the defenition of the same from the aspx.cs page. Create an interface to define two methods one to hide arrows in the grid and other to get the sort order of the grid.

public interface IMethods
{
void SortRecords(string buttonName,string ColumnName,HtmlImage lnkSortCode);
void HideSortIcons(string buttonName,string UniqueID);
}
public abstract class AbstractClass:System.Web.UI.Page
{
  public AbstractClass()
  {
  }
  public abstract string ListGridView(int CurrentPage,int PagingSize,string SortOrder);
}