C#

// object FilterValue = comboBoxValue.SelectedValue;

MyClass filterValue = comboBoxValue.SelectedValue as MyClass;

if (comboBoxValue.SelectedValue == null)
{
    //TODO: clear results
    return;
}

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form2 frm2;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            frm2 = new Form2();
            frm2.MyVar = textBox1.Text;

            frm2.Show();
            
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (frm2 != null)
            {
                frm2.MyVar = textBox1.Text;
            }
        }

	}
}

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        public string MyVar
        {
            set
            {
                textBox1.Text = value;
            }
        }
    }
}

public class Form1 : Form
{
    public delegate void StringTransportingEvent(string value);
    public event StringTransportingEvent VariableChanged;

    override void OnLoad()
    {
        Form2 secondForm = new Form2(this);
        secondForm.Show();
    }

    textBox1_TextChanged(object sender, EventArgs e)
    {
        EventHandler eh = VariableChanged;
        if( eh != null)
        {
            eh(textBox1.Text);
        }
    }
}

public class Fomr2 : Form
{
    public Form2(Form1 eventRaiser)
    {
        eventRaiser.VariableChanged += Form1_VariableChanged;
    }


    private void Form1_VariableChanged(string value)
    {
        this.TextBox1.Text = value;
    }
}

faraz34 wrote:

but i didn't get an explicit answer

class MyDgv : DataGridView
{
    public override Image BackgroundImage
    {
        get
        {
            return base.BackgroundImage;
        }
        set
        {
            base.BackgroundImage = value;
        }
    }
    protected override void PaintBackground(
        Graphics graphics, Rectangle clipBounds, Rectangle gridBounds)
    {
        base.PaintBackground(graphics, clipBounds, gridBounds);
        graphics.DrawImage(BackgroundImage, new Point(0, 0));
    }
}

public partial class Form1 : Form
{
    MyDgv _dgv = new MyDgv();

    public Form1()
    {
        InitializeComponent();

        _dgv.Dock = DockStyle.Fill;
        _dgv.BackgroundImage = Image.FromFile(
            @"C:\Users\Eddy PC\Pictures\untitled.bmp");
        _dgv.DataSource = new List<DateTime>() { 
            DateTime.MinValue, 
            DateTime.Now, 
            DateTime.MaxValue };
        this.Controls.Add(_dgv);
    }
}

Bastard Programmer from Hell