Hi there!
Check out my solution. You should be able to more or less copy and paste it and adjust for your use:
Markup:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="ListBox.aspx.cs" Inherits="ASPNET.ListBox" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h4>Authors in DB</h4>
<asp:ListBox runat="server" ID="AuthorsListBox" Height="200px" Rows="5"></asp:ListBox>
</div>
<div>
<h4>Search</h4>
<label>Search Author:</label>
<asp:TextBox runat="server" ID="SearchTextBox" />
</div>
<div>
<asp:Button runat="server" ID="SearchButton"
Text="Search" OnClick="SearchButton_Click" />
<asp:button runat="server" ID="ResetSearchButton"
Text="Clear" OnClick="ResetSearchButton_Click" />
</div>
<div>
<h4>Search Results</h4>
<asp:DataList runat="server" ID="AuthorsDataList">
<ItemTemplate>
<label>
<%#Eval("AuthorName") %>
</label>
</ItemTemplate>
</asp:DataList>
</div>
</form>
</body>
</html>
Code behind:
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace ASPNET
{
public partial class ListBox : System.Web.UI.Page
{
/// <summary>
/// A local data source variable.
/// </summary>
private List<Author> _Authors;
/// <summary>
/// Gets or sets the search text box.
/// </summary>
private string _SearchBoxText
{
get { return SearchTextBox.Text; }
set { SearchTextBox.Text = value; }
}
/// <summary>
/// Pre load data.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_PreInit(object sender, EventArgs e)
{
_Authors = MockAuthors.GetMockAuthorData();
}
/// <summary>
/// Set controls.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
AuthorsListBox.DataSource = _Authors.Select(x => x.AuthorName);
AuthorsListBox.DataBind();
}
AuthorsListBox.SelectionMode = ListSelectionMode.Multiple;
}
/// <summary>
/// Returns only an array of the author names.
/// </summary>
/// <returns></returns>
private IEnumerable<string> GetAuthorNames()
{
if(_Authors.Any())
{
return _Authors.Select(x => x.AuthorName);
}
return new string[] { };
}
/// <summary>
/// Resets controls for new search.
/// </summary>
private void ResetSearch()
{
AuthorsListBox.SelectedIndex = -1;
_SearchBoxText = string.Empty;
AuthorsDataList.DataSource = null;
AuthorsDataList.DataBind();
SearchTextBox.Focus();
}
/// <summary>
/// Performs search of author names. Then selects each matching data list item in global list.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void SearchButton_Click(object sender, EventArgs e)
{
// Reset the controls from the previous search.
AuthorsListBox.SelectedIndex = -1;
// Search authors with matching search text
List<Author> authorsMatchingSearch =
_Authors
.Where(x =>
x.AuthorName.ToLower().Contains(_SearchBoxText))
.ToList();
AuthorsDataList.DataSource = authorsMatchingSearch;
AuthorsDataList.DataBind();
// Add logic to do something when no matches found.
// Select the authors from main list
foreach (ListItem item in AuthorsListBox.Items)
{
if (authorsMatchingSearch
.Select(x => x.AuthorName.ToLower())
.Contains(item.Text.ToLower()))
{
item.Selected = true;
}
}
}
/// <summary>
/// Resets the form.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void ResetSearchButton_Click(object sender, EventArgs e)
{
ResetSearch();
}
}
/// <summary>
/// A data model representing an Author entity.
/// </summary>
public class Author
{
/// <summary>
/// The name of the Author.
/// </summary>
public string AuthorName { get; set; }
}
/// <summary>
/// Generates mock data.
/// </summary>
public static class MockAuthors
{
/// <summary>
/// Mocks up Authors List.
/// </summary>
/// <returns></returns>
public static List<Author> GetMockAuthorData()
{
return new List<Author>
{
new Author
{
AuthorName = "James Smith"
},
new Author
{
AuthorName = "Sally Cunnigham"
},
new Author
{
AuthorName = "Billy Buffinger"
},
new Author
{
AuthorName = "James Jones"
},
new Author
{
AuthorName = "James Cunningham"
}
};
}
}
}
Submit an article or tip