C#

uint ToUInt(int value)
{
    return value < 0 ? (uint)(int.MaxValue - value) : (uint)value;
}
int ToInt(uint value)
{
    return value > int.MaxValue ? (int)(int.MaxValue - value) : (int)value;
}

namespace ModelDialogExceptions
{
    public partial class  MainForm : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                ModelDialog mdl = new ModelDialog();
                mdl.ShowDialog(); 
            }
            catch (Exception exc)// caught only in the Debug build
            {
                MessageBox.Show("Exception captured!!!");
            }
        }
    }
}

namespace ModelDialogExceptions
{
    public partial class ModelDialog : Form
    {
        public ModelDialog()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            throw new System.IO.FileNotFoundException("");
        }
    }
}