Monday 30 January 2012

Search Records In GridView And Highlight Results Asp.Net Ajax

Search Records In GridView And Highlight Results Asp.Net Ajax

 

In this example i am searching records of gridview and highlighting the results based on search criteria user enter in textbox .

This example is using AJAX and C# asp.NET



<%@ Page Language="C#" AutoEventWireup="true"
CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Grid Search example</title>
<style type="text/css">
.highlight {
text-decoration:none; font-weight:bold;
color:black; background:yellow;}
</style>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1"
runat="server" />

<div>
Enter first name to search:
</div>
<div>
<asp:TextBox ID="txtSearch" runat="server"
AutoPostBack="True"
OnTextChanged="txtSearch_TextChanged">
</asp:TextBox>&nbsp;
</div>
<div>
<asp:UpdatePanel ID="UpdatePanel1"
runat="server">
<ContentTemplate>
<asp:GridView ID="grdSearch"
runat="server"
AutoGenerateColumns="false">
<Columns>
<asp:TemplateField HeaderText="FirstName">
<ItemTemplate>
<asp:Label ID="lblFirstName"
runat="server"
Text='<%# Highlight(Eval("FirstName").ToString()) %>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="LastName">
<ItemTemplate>
<asp:Label ID="lblLastName" runat="server"
Text='<%#(Eval("LastName")) %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Location">
<ItemTemplate>
<asp:Label ID="lblLocation" runat="server"
Text='<%#(Eval("Location")) %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="txtSearch"
EventName="TextChanged" />
</Triggers>
</asp:UpdatePanel>

</div>

</form>
</body>
</html>

And it code behind
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Text.RegularExpressions;

public partial class _Default : System.Web.UI.Page
{
string strConnection =
ConfigurationManager.AppSettings["ConnectionString"];
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindGrid();
}
}

private DataTable GetRecords()
{
SqlConnection conn = new SqlConnection(strConnection);
conn.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "Select * from Employees";
SqlDataAdapter dAdapter = new SqlDataAdapter();
dAdapter.SelectCommand = cmd;
DataSet objDs = new DataSet();
dAdapter.Fill(objDs);
return objDs.Tables[0];

}
private void BindGrid()
{
DataTable dt = GetRecords();
if (dt.Rows.Count > 0)
{
grdSearch.DataSource = dt;
grdSearch.DataBind();
}
}
private void SearchText()
{
DataTable dt = GetRecords();
DataView dv = new DataView(dt);
string SearchExpression = null;
if (!String.IsNullOrEmpty(txtSearch.Text))
{
SearchExpression = string.Format("{0} '%{1}%'",
grdSearch.SortExpression, txtSearch.Text);

}
dv.RowFilter = "FirstName like" + SearchExpression;
grdSearch.DataSource = dv;
grdSearch.DataBind();

}
public string Highlight(string InputTxt)
{
string Search_Str = txtSearch.Text.ToString();
// Setup the regular expression and add the Or operator.
Regex RegExp = new Regex(Search_Str.Replace(" ", "|").Trim(),
RegexOptions.IgnoreCase);

// Highlight keywords by calling the 
//delegate each time a keyword is found.
return RegExp.Replace(InputTxt,
new MatchEvaluator(ReplaceKeyWords));

// Set the RegExp to null.
RegExp = null;

}

public string ReplaceKeyWords(Match m)
{

return "<span class=highlight>" + m.Value + "</span>";

}

protected void txtSearch_TextChanged(object sender, EventArgs e)
{
SearchText();
}
}


Download the sample code

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