Change GridView Cell color based on condition using C# and VB.Net in ASP.Net

Hi kankon,

Use GridView RowDataBound event and check the cell value to set the color.

Check this example. Now please take its reference and correct your code.

I have binded GridView using temporary Datatable. You have to use your code for binding the GridView from database using stored procedure.

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowEditing="OnRowEditing" OnRowDataBound="OnRowDataBound"
    OnRowUpdating="OnRowUpdating" OnRowCancelingEdit="OnRowCancelingEdit" OnRowDeleting="OnRowDeleting">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:TemplateField HeaderText="Time">
            <ItemTemplate>
                <asp:Label ID="lblTime" runat="server" Text='<%# Eval("Time", "{0:hh:mm tt}") %>'></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:CommandField ButtonType="Link" ShowEditButton="true" ShowDeleteButton="true" />
    </Columns>
</asp:GridView>

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)
    {
        BindGrid();
    }
}

private void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[3] {
        new DataColumn("Id"), new DataColumn("Name"), new DataColumn("Time", typeof(DateTime)) });
    dt.Rows.Add(1, "John Hammond", "2020-05-05 1:20 PM");
    dt.Rows.Add(2, "Mudassar Khan", "2020-05-05 10:30 AM");
    dt.Rows.Add(3, "Suzanne Mathews", "2020-05-05 9:23 AM");
    dt.Rows.Add(4, "Robert Schidner", "2020-05-05 4:50 PM");
    GridView1.DataSource = dt;
    GridView1.DataBind();
}

protected void OnRowEditing(object sender, GridViewEditEventArgs e)
{
    GridView1.EditIndex = e.NewEditIndex;
    this.BindGrid();
}

protected void OnRowUpdating(object sender, GridViewUpdateEventArgs e)
{
    GridView1.EditIndex = -1;
    this.BindGrid();
}

protected void OnRowCancelingEdit(object sender, EventArgs e)
{
    GridView1.EditIndex = -1;
    this.BindGrid();
}

protected void OnRowDeleting(object sender, GridViewDeleteEventArgs e)
{
    this.BindGrid();
}

protected void OnRowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex != GridView1.EditIndex)
    {
        (e.Row.Cells[3].Controls[2] as LinkButton).Attributes["onclick"] = "return confirm('Do you want to delete this row?');";
        DateTime time = Convert.ToDateTime((e.Row.FindControl("lblTime") as Label).Text);
        if (time.ToString("tt").ToUpper() == "PM")
        {
            (e.Row.FindControl("lblTime") as Label).ForeColor = Color.Red;
        }
        if (time.ToString("tt").ToUpper() == "AM")
        {
            (e.Row.FindControl("lblTime") as Label).ForeColor = Color.Blue;
        }
    }
}

VB.Net

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

Private Sub BindGrid() Handles Me.Load
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn(2) {
                        New DataColumn("Id"), New DataColumn("Name"), New DataColumn("Time", GetType(DateTime))})
    dt.Rows.Add(1, "John Hammond", "2020-05-05 1:20 PM")
    dt.Rows.Add(2, "Mudassar Khan", "2020-05-05 10:30 AM")
    dt.Rows.Add(3, "Suzanne Mathews", "2020-05-05 9:23 AM")
    dt.Rows.Add(4, "Robert Schidner", "2020-05-05 4:50 PM")
    GridView1.DataSource = dt
    GridView1.DataBind()
End Sub

Protected Sub OnRowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
    GridView1.EditIndex = e.NewEditIndex
    Me.BindGrid()
End Sub

Protected Sub OnRowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
    GridView1.EditIndex = -1
    Me.BindGrid()
End Sub

Protected Sub OnRowCancelingEdit(ByVal sender As Object, ByVal e As EventArgs)
    GridView1.EditIndex = -1
    Me.BindGrid()
End Sub

Protected Sub OnRowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)
    Me.BindGrid()
End Sub

Protected Sub OnRowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
    If e.Row.RowType = DataControlRowType.DataRow AndAlso e.Row.RowIndex <> GridView1.EditIndex Then
        TryCast(e.Row.Cells(3).Controls(2), LinkButton).Attributes("onclick") = "return confirm('Do you want to delete this row?');"
        Dim time As DateTime = Convert.ToDateTime((TryCast(e.Row.FindControl("lblTime"), Label)).Text)

        If time.ToString("tt").ToUpper() = "PM" Then
            TryCast(e.Row.FindControl("lblTime"), Label).ForeColor = Color.Red
        End If
        If time.ToString("tt").ToUpper() = "AM" Then
            TryCast(e.Row.FindControl("lblTime"), Label).ForeColor = Color.Blue
        End If
    End If
End Sub

Screenshot