interface LoadBehavior
    {
        void Load(System.Windows.Forms.DataGridView dwg);
    }

    class LoadFromTxt: LoadBehavior
    {
        void Load(System.Windows.Forms.DataGridView dwg)
        {
            /** Load data from text file */
        }
    }

    class LoadFromInternet: LoadBehavior
    {
        public void Load(System.Windows.Forms.DataGridView dwg)
        { 
            /** Load data from internet  */
        }
    }

    class Loader
    {     
        LoadBehavior loadBehavior
        System.Windows.Forms.DataGridView dvg;

        public void SetDataGridView(System.Windows.Forms.DataGridView dvg)
        {
            this.dvg = dvg;
        }

        public void LoadBehavior(LoadBehavior loadBehavior)
        {
            this.loadBehavior = loadBehavior;
            
        }

        public void Load()
        {
            this.loadBehavior.Load(dvg);
        }
    }