Allow Paging in Repeater and DataList Using C#

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Introduction

The Repeater and DataList are two very important controls and many developers use at least one of them in most of their websites or web applications. Also, these Controls are easy to use for UI developers, but their features are limited. The Gridview control has a very useful paging feature, but it's a complex control and you might not want to use it. And, if you want to use a Repeater or a DataList, they do not support paging, so what will you do ?!!

I will show you how to make a Repeater or a DataList that allows paging. I'll also make a web user control that anyone can use to allow paging in a Repeater or DataList control.

How to Decide to Use the DataGrid, DataList, or Repeater

The URL below describes the differences between a DataGrid, DataList, and a Repeater and helps to decide which one to use: http://msdn.microsoft.com/en-us/library/aa479015.aspx.

Advantages of the AllowPaging Control

It enables paging in Repeater and DataList controls. It is an easy to use Web User Control. The control depends on ObjectDataSource so, if you want to use SqlDataSource, just replace ObjectDataSource with SqlDataSource.

Using the code

The sample code is divided into three parts:

1. The Default Page to add a Repeater or DataList control.
2. The UCPager Web User Control that is responsible for paging.
3. The GetData class to get data from the database.

Also, I'm using the Northwind database in this sample.

First, I'll talk about the User Control sample code. There are four important properties:

• CurrentPage - sets or gets the current page number
• Ods - pass to it the ObjectDataSource
• ObjectControl - pass a Repeater or DataList
• PageSize - pass an integer for how many records will appear in each page

/// <summary>
/// set or get the Current Page Number
/// </summary>
public int CurrentPage
{
    get
    {
        //get current page number
        object obj = this.ViewState["_CurrentPage"];
        if (obj == null)
        {
            return 0;
        }
        else
        {
            return (int)obj;
        }
    }
    set
    {
        //set in viewstate the current page number
        this.ViewState["_CurrentPage"] = value;
    }
}

/// <summary>
/// set or get ObjectDataSource that's use to bind the control
/// Like(Repeater or Datalist)
/// </summary>
public ObjectDataSource Ods { get; set; }

/// <summary>
/// set or get Control Name EX. (Repeater1 or Datalist1)
/// </summary>
public object ObjectControl { get; set; }

/// <summary>
/// set or get count of pages
/// page size determine how many records will appears in every page
/// </summary>
public int PageSize { get; set; }

The method below is responsible for binding a control and enabling or disabling the navigation buttons depending on how records are shown.

/// <summary>
/// bind controls with data
/// enable and disable controls depending on page number
/// check for object Control if it a Repeater or a DataList
/// </summary>
/// <returns>the count of pages</returns>
private int GetItems()
{
    //create new instance of PagedDataSource
    PagedDataSource objPds = new PagedDataSource();
    //set number of pages will appear
    objPds.PageSize = PageSize;
    objPds.DataSource = Ods.Select();
    objPds.AllowPaging = true;
    int count = objPds.PageCount;
    objPds.CurrentPageIndex = CurrentPage;
    if (objPds.Count > 0)
    {
        //dispaly controls if there are pages
        btnPrevious.Visible = true;
        btnNext.Visible = true;
        btnLastRecord.Visible = true;
        btnFirstRecord.Visible = true;
        lblCurrentPage.Visible = true;
        lblCurrentPage.Text = "Page " + 
          Convert.ToString(CurrentPage + 1) + " of " + 
          Convert.ToString(objPds.PageCount);
    }
    else
    {
        //disable controls if there are no pages
        btnPrevious.Visible = false;
        btnNext.Visible = false;
        btnLastRecord.Visible = false;
        btnFirstRecord.Visible = false;
        lblCurrentPage.Visible = false;
    }
    btnPrevious.Enabled = !objPds.IsFirstPage;
    btnNext.Enabled = !objPds.IsLastPage;
    btnLastRecord.Enabled = !objPds.IsLastPage;
    btnFirstRecord.Enabled = !objPds.IsFirstPage;
    //check for object control if it a DataList
    //we will use DList Variable
    if (ObjectControl is DataList)
    {
        DList = (DataList)ObjectControl;
        DList.DataSource = objPds;
        DList.DataBind();
    }
    //check for object control if it a Repeater
    //we will use Rep Variable
    else if (ObjectControl is Repeater)
    {
        Rep = (Repeater)ObjectControl;
        Rep.DataSource = objPds;
        Rep.DataBind();
    }
    return count;
}

In the First Record button:

//go to first Page
CurrentPage = 0;

GetItems();

In the Last Record button:

//go to last page
CurrentPage = GetItems() -1;

GetItems();

In the Previous Record button:

//back to previous page
CurrentPage -= 1;

GetItems();

In the Next Record button:

//go to next page
CurrentPage += 1;

GetItems();

In the Default Page, all you need is bind the AllowPaging control properties, and the code below explains that:

UCPager1.Ods = ObjEmployees;

UCPager1.ObjectControl = Repeater1;

UCPager1.PageSize = 1;

I'm waiting for your comments. You can read my blog here: http://waleedelkot.blogspot.com/.

Points of Interest

This control saves a lot of time for me, and I hope it helps you too.

History

• 27-08-2009: First version released.

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)