public partial class Form1: Form
    {
        private IEObjectLine ieobjectline;
        public Form1()
        {
            InitializeComponent();
           
        }

        private void button1_Click(object sender, EventArgs e)
        {
            ieobjectline = (IEObjectLine)ieViewer1.Image.Annotations.GetTemplateObject(IEObjectType.Line);

            ieobjectline.Name = "Line";
            ieobjectline.Left = 0;
            ieobjectline.Top = 100;
            ieobjectline.Width = 200;
            ieobjectline.Height = 1;
            ieobjectline.Transparency = 255;
 
            ieobjectline.PenWidth = 1;
            ieobjectline.PenColor = new IERGB(Color.Black);
            ieobjectline.PenStyle = IEPenStyles.Solid;

            ieViewer1.EnableObjectInserting = IEViewer.ObjectInserting.Line;

        }

        private void ieViewer1_MouseMove(object sender, MouseEventArgs e)
        {
            if (ieobjectline != null)
            {
               Console.WriteLine(ieobjectline.Left.ToString() + ", " + ieobjectline.Top.ToString() + ", " + ieobjectline.Width.ToString() + ", " + ieobjectline.Height.ToString());

            }

        }

}