public class CalendarConditionalCellStyle : CalendarNamedCellStyle 

using System;
using System.Windows.Forms;
using System.Drawing;
using GrapeCity.Win.CalendarGrid;

namespace CalendarGridSampleCode
{
    public class ConditionalCellStyleDemo : Form
    {
        private GcCalendarGrid gcCalendarGrid1 = new GcCalendarGrid();
        private Label label1 = new Label();

        public ConditionalCellStyleDemo()
        {
            this.Text = "ConditionalCellStyle Demo";
            this.Size = new Size(600, 400);

            this.gcCalendarGrid1.Dock = DockStyle.Fill;
            this.Controls.Add(this.gcCalendarGrid1);

            label1.Text = "When specified date match condition, the corresponding background will be painted.";
            label1.Height = 50;
            label1.Dock = DockStyle.Bottom;
            label1.BackColor = SystemColors.Info;
            label1.ForeColor = Color.Red;
            this.Controls.Add(label1);

            this.Load += Form1_Load;

            this.StartPosition = FormStartPosition.CenterScreen;
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            CalendarCellStyle cellStyle1 = new CalendarCellStyle();
            cellStyle1.BackColor = Color.Lime;

            CalendarCellStyle cellStyle2 = new CalendarCellStyle();
            cellStyle2.BackColor = Color.Yellow;

            CalendarCellStyle cellStyle3 = new CalendarCellStyle();
            cellStyle3.BackColor = Color.Red;

            CalendarConditionalCellStyleItem item1 = new CalendarConditionalCellStyleItem(cellStyle1, ConditionalStyleOperator.IsMonday);            
            CalendarConditionalCellStyleItem item2 = new CalendarConditionalCellStyleItem(cellStyle2, ConditionalStyleOperator.IsFriday);          
            CalendarConditionalCellStyleItem item3 = new CalendarConditionalCellStyleItem(cellStyle3, ConditionalStyleOperator.IsTrailingDay);
        
            CalendarConditionalCellStyle conditionalStyle1 = new CalendarConditionalCellStyle("defaultCalendarConditionalStyle");
            conditionalStyle1.Items.Add(item1);
            conditionalStyle1.Items.Add(item2);
            conditionalStyle1.Items.Add(item3);
            this.gcCalendarGrid1.Styles.Clear();
            this.gcCalendarGrid1.Template.Content.GetCell(0, 0).CellStyleName = "defaultCalendarConditionalStyle";
            this.gcCalendarGrid1.Styles.Add(conditionalStyle1);
        }

        [STAThreadAttribute()]
        public static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new ConditionalCellStyleDemo());
        }
    }
}