Search Records In GridView And Highlight Results Asp.Net Ajax

In this example i am Explaining how to Search Records In GridView And Highlight Results Using Ajax In Asp.Net 2.0,3.5,4.0 based on text entered in textbox.



Add following CSS style in head section of page.

show source

1<style type="text/css">

2.highlight

3{

4text-decoration:none; font-weight:bold;

5color:black; background:yellow;

6}

7</style>

HTML SOURCE

---

<asp:ScriptManager ID="ScriptManager1" runat="server"/>

Enter first name to search:

<asp:TextBox ID="txtSearch" runat="server" AutoPostBack="True"

             OnTextChanged="txtSearch_TextChanged"/>

<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()) %>'/>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="LastName">

<ItemTemplate>

<asp:Label ID="lblLastName" runat="server" Text='<%#(Eval("LastName")) %>'/>

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="Location">

<ItemTemplate>

<asp:Label ID="lblLocation" runat="server" Text='<%#(Eval("Location")) %>'/>

</ItemTemplate>

</asp:TemplateField>

</Columns>

</asp:GridView>

</ContentTemplate>

<Triggers>

<asp:AsyncPostBackTrigger ControlID="txtSearch" EventName="TextChanged" />

</Triggers>

</asp:UpdatePanel>

Write following code in code behind
C# CODE

---

show source

01protected void Page_Load(object sender, EventArgs e)

02    {

03        if (!IsPostBack)

04        {

05            BindGrid();

06        }

07    }

08    private DataTable GetRecords()

09    {

10        SqlConnection conn = new SqlConnection(strConnection);

11        conn.Open();

12        SqlCommand cmd = new SqlCommand();

13        cmd.Connection = conn;

14        cmd.CommandType = CommandType.Text;

15        cmd.CommandText = "Select * from Employees";

16        SqlDataAdapter dAdapter = new SqlDataAdapter();

17        dAdapter.SelectCommand = cmd;

18        DataSet objDs = new DataSet();

19        dAdapter.Fill(objDs);

20        return objDs.Tables[0];

21 

22    }

23    private void BindGrid()

24    {

25        DataTable dt = GetRecords();

26        if (dt.Rows.Count > 0)

27        {

28            grdSearch.DataSource = dt;

29            grdSearch.DataBind();

30        }

31    }

32    private void SearchText()

33    {

34        DataTable dt = GetRecords();

35        DataView dv = new DataView(dt);

36        string SearchExpression = null;

37        if (!String.IsNullOrEmpty(txtSearch.Text))

38        {

39            SearchExpression = string.Format("{0} '%{1}%'",

40            grdSearch.SortExpression, txtSearch.Text);

41 

42        }

43        dv.RowFilter = "FirstName like" + SearchExpression;

44        grdSearch.DataSource = dv;

45        grdSearch.DataBind();

46 

47    }

48    public string Highlight(string InputTxt)

49    {

50        string Search_Str = txtSearch.Text.ToString();

51        // Setup the regular expression and add the Or operator.

52        Regex RegExp = new Regex(Search_Str.Replace(" ", "|").Trim(),

53        RegexOptions.IgnoreCase);

54 

55        // Highlight keywords by calling the

56        //delegate each time a keyword is found.

57        return RegExp.Replace(InputTxt,

58        new MatchEvaluator(ReplaceKeyWords));

59 

60        // Set the RegExp to null.

61        RegExp = null;

62 

63    }

64 

65    public string ReplaceKeyWords(Match m)

66    {

67 

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

69 

70    }

71 

72    protected void txtSearch_TextChanged(object sender, EventArgs e)

73    {

74        SearchText();

75    }

VB.NET

---

show source

01Protected Sub Page_Load(sender As Object, e As EventArgs)

02 If Not IsPostBack Then

03  BindGrid()

04 End If

05End Sub

06Private Function GetRecords() As DataTable

07 Dim conn As New SqlConnection(strConnection)

08 conn.Open()

09 Dim cmd As New SqlCommand()

10 cmd.Connection = conn

11 cmd.CommandType = CommandType.Text

12 cmd.CommandText = "Select * from Employees"

13 Dim dAdapter As New SqlDataAdapter()

14 dAdapter.SelectCommand = cmd

15 Dim objDs As New DataSet()

16 dAdapter.Fill(objDs)

17 Return objDs.Tables(0)

18 

19End Function

20Private Sub BindGrid()

21 Dim dt As DataTable = GetRecords()

22 If dt.Rows.Count > 0 Then

23  grdSearch.DataSource = dt

24  grdSearch.DataBind()

25 End If

26End Sub

27Private Sub SearchText()

28 Dim dt As DataTable = GetRecords()

29 Dim dv As New DataView(dt)

30 Dim SearchExpression As String = Nothing

31 If Not [String].IsNullOrEmpty(txtSearch.Text) Then

32 

33  SearchExpression = String.Format("{0} '%{1}%'", grdSearch.SortExpression, txtSearch.Text)

34 End If

35 dv.RowFilter = "FirstName like" & SearchExpression

36 grdSearch.DataSource = dv

37 grdSearch.DataBind()

38 

39End Sub

40Public Function Highlight(InputTxt As String) As String

41 Dim Search_Str As String = txtSearch.Text.ToString()

42 ' Setup the regular expression and add the Or operator.

43 Dim RegExp As New Regex(Search_Str.Replace(" ", "|").Trim(), RegexOptions.IgnoreCase)

44 

45 ' Highlight keywords by calling the

46 'delegate each time a keyword is found.

47 Return RegExp.Replace(InputTxt, New MatchEvaluator(AddressOf ReplaceKeyWords))

48 

49 ' Set the RegExp to null.

50 RegExp = Nothing

51 

52End Function

53 

54Public Function ReplaceKeyWords(m As Match) As String

55 

56 Return "<span class="highlight">" & Convert.ToString(m.Value) & "</span>"

57 

58End Function

59 

60Protected Sub txtSearch_TextChanged(sender As Object, e As EventArgs)

61 SearchText()

62End Sub

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