Highlight DataList Item based on Session DataTable data using C# and VB.Net in ASP.Net

Hi sat,

Check below example.

HTML

<asp:DataList runat="server" ID="dlStudentsDetails" OnItemDataBound="OnItemDataBound">
    <ItemTemplate>
        <table>
            <tr>
                <td>StudentId</td>
                <td>
                    <asp:Label ID="lblID" Text='<%# Eval("StudentID") %>' runat="server" /></td>
            </tr>
            <tr>
                <td>Phy</td>
                <td>
                    <asp:Label ID="lblPhy" Text='<%# Eval("Phy") %>' runat="server" /></td>
            </tr>
            <tr>
                <td>Chm</td>
                <td>
                    <asp:Label ID="lblChm" Text='<%# Eval("Chm") %>' runat="server" /></td>
            </tr>
            <tr>
                <td>Mth</td>
                <td>
                    <asp:Label ID="lblMth" Text='<%# Eval("Mth") %>' runat="server" /></td>
            </tr>
        </table>
    </ItemTemplate>
</asp:DataList>

Namespaces

C#

using System.Data;
using System.Drawing;

VB.Net

Imports System.Data
Imports System.Drawing

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindStudentSession();
        this.BindDetails();
    }
}

private void BindStudentSession()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { new DataColumn("StudentID"), new DataColumn("Attended"), new DataColumn("FeesPaid") });
    dt.Rows.Add("0002", "Yes", "No");
    dt.Rows.Add("0004", "No", "No");
    Session["Students"] = dt;
}

private void BindDetails()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { new DataColumn("StudentID"), new DataColumn("Phy"), new DataColumn("Chm"), new DataColumn("Mth") });
    dt.Rows.Add("0001", "98", "95", "99");
    dt.Rows.Add("0002", "95", "86", "94");
    dt.Rows.Add("0003", "94", "97", "93");
    dt.Rows.Add("0004", "95", "96", "95");
    this.dlStudentsDetails.DataSource = dt;
    this.dlStudentsDetails.DataBind();
}

protected void OnItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        string id = ((e.Item as DataListItem).FindControl("lblID") as Label).Text;
        DataTable dt = Session["Students"] as DataTable;
        foreach (DataRow row in dt.Rows)
        {
            string sId = row["StudentID"].ToString();
            if (id == sId)
            {
                ((e.Item as DataListItem).FindControl("lblID") as Label).BackColor = Color.Yellow;
                break;
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not Me.IsPostBack Then
        Me.BindStudentSession()
        Me.BindDetails()
    End If
End Sub

Private Sub BindStudentSession()
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("StudentID"), New DataColumn("Attended"), New DataColumn("FeesPaid")})
    dt.Rows.Add("0002", "Yes", "No")
    dt.Rows.Add("0004", "No", "No")
    Session("Students") = dt
End Sub

Private Sub BindDetails()
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("StudentID"), New DataColumn("Phy"), New DataColumn("Chm"), New DataColumn("Mth")})
    dt.Rows.Add("0001", "98", "95", "99")
    dt.Rows.Add("0002", "95", "86", "94")
    dt.Rows.Add("0003", "94", "97", "93")
    dt.Rows.Add("0004", "95", "96", "95")
    Me.dlStudentsDetails.DataSource = dt
    Me.dlStudentsDetails.DataBind()
End Sub

Protected Sub OnItemDataBound(ByVal sender As Object, ByVal e As DataListItemEventArgs)
    If e.Item.ItemType = ListItemType.Item OrElse e.Item.ItemType = ListItemType.AlternatingItem Then
        Dim id As String = TryCast((TryCast(e.Item, DataListItem)).FindControl("lblID"), Label).Text
        Dim dt As DataTable = TryCast(Session("Students"), DataTable)
        For Each row As DataRow In dt.Rows
            Dim sId As String = row("StudentID").ToString()
            If id = sId Then
                TryCast((TryCast(e.Item, DataListItem)).FindControl("lblID"), Label).BackColor = Color.Yellow
                Exit For
            End If
        Next
    End If
End Sub

Screenshot