Paging ListView With DataPager

• Download ListView - 4.26 KB

Introduction

Recently, I receive some e-mail about ListView from colleagues/friends who want to Paging the ListView, but the DataSource must be set programatically. Then, I do some tests and get the result that follows.

Background

Paging the ListView with DataPager is very easy and you can't write some code. Just add and configure a DataSource, add a ListView, set the DataSource to ListView. Add a DataPager and configure it to ListView. Done!

Run app and enjoy it!

But, when the DataSource is set in code, some cautions must be done. Now, to populate the ListView, you must use the DataPager.

Using the code

Let't try. Add a ListView:

<asp:ListView ID="ListViewProducts" runat="server" ItemPlaceholderID="ProductItem">
    <ItemTemplate>
        <div class="Product">
            <strong>
                <asp:Label runat="server" ID="LabelId" Text='<%# Eval("Id") %>'></asp:Label>
                ::
                <asp:Label runat="server" ID="LabelName" Text='<%# Eval("Name") %>'></asp:Label>
            </strong>
            <br />
            <em>
                <asp:Label runat="server" ID="LabelDescription" Text='<%# Eval("Description") %>'></asp:Label>
            </em>
        </div>
    </ItemTemplate>
    <LayoutTemplate>
        <asp:PlaceHolder runat="server" ID="ProductItem"></asp:PlaceHolder>
    </LayoutTemplate>
    <ItemSeparatorTemplate>
        <hr />
    </ItemSeparatorTemplate>
</asp:ListView> 

Then, add the DataPager:

<asp:DataPager ID="DataPagerProducts" runat="server" PagedControlID="ListViewProducts"
    PageSize="3" OnPreRender="DataPagerProducts_PreRender">
    <Fields>
        <asp:NextPreviousPagerField ShowFirstPageButton="True" ShowNextPageButton="False" />
        <asp:NumericPagerField />
        <asp:NextPreviousPagerField ShowLastPageButton="True" ShowPreviousPageButton="False" />
    </Fields>
</asp:DataPager>

See that the event OnPreRender was implemented. It's used to populate the ListView:

protected void DataPagerProducts_PreRender(object sender, EventArgs e)
{
    ProductList db = new ProductList();
    this.ListViewProducts.DataSource = db.GellAll();
    this.ListViewProducts.DataBind();
}

I create two class to help this example:

1) Product: represent a product item;
2) ProductList: represent a database access layer.

ProductClass

using System;

/// <summary>
/// Class that represent a product item.
/// </summary>
public class Product
{
    private int? _Id;
    private string _Name;
    private string _Descrition;

    public Product(){}

    public Product(int Id, string Name, string Description)
    {
        this._Id = Id;
        this._Name = Name;
        this._Descrition = Description;
    }

    /// <summary>
    /// Product Id
    /// </summary>
    public int? Id
    {
        get { return _Id; }
        set { _Id = value; }
    }

    /// <summary>
    /// Product Name
    /// </summary>
    public string Name
    {
        get { return _Name; }
        set { _Name = value; }
    }

    /// <summary>
    /// Product Complete Description
    /// </summary>
    public string Description
    {
        get { return _Descrition; }
        set { _Descrition = value; }
    }
}

ProductList Class

using System;
using System.Collections.Generic;

/// <summary>
/// Simulation of a Product Database
/// </summary>
public class ProductList
{
    private IList<Product> _ProductDB = new List<Product>();

    public ProductList()
    {
        this._ProductDB.Add(new Product(1, "Computer", "Complete hardware with software included."));
        this._ProductDB.Add(new Product(2, "Kitchen Calendar", "Beautiful caledar for your kitchen."));
        this._ProductDB.Add(new Product(3, "Shoes", "Most advanced anti-impact system in a small shoe."));
        this._ProductDB.Add(new Product(4, "Pen", "What you think, must be written. This pen is your helper."));
        this._ProductDB.Add(new Product(5, "Cell Phone", "Powerfull comunication thing. Today is part of your body. Get one more."));
    }

    public IList<Product> GellAll()
    {
        return this._ProductDB;
    }
} 

Points of Interest

Interesting Articles:

• http://msdn2.microsoft.com/en-us/library/system.web.ui.webcontrols.datapager.aspx
• http://aspnet.4guysfromrolla.com/articles/021308-1.aspx
• http://www.west-wind.com/WebLog/posts/127340.aspx
  

History

2008-03-03 - First insert.