CheckExportFile();

        private void buttonCheck_Click(object sender, EventArgs e) 
        {
            ProgressBar();
            CheckExportFile();
        }

        void ProgressBar()
        {
            ProgressBar progressBar = new ProgressBar
            {
                Location = new System.Drawing.Point(227, 19),
                Name = "progressBar",
                Size = new System.Drawing.Size(300, 23),
                Step = 1,
                Style = System.Windows.Forms.ProgressBarStyle.Marquee,
                TabIndex = 6
            };


            Action<ProgressBar> action = AddProgressBar;

            if (this.groupBoxStatus.InvokeRequired)
            {
                this.groupBoxStatus.Invoke(action, progressBar);
            }
            else
            {
                action(progressBar);
            }

           // this.groupBoxStatus.Controls.Add(progressBar);
        }

        void AddProgressBar(ProgressBar progressBar)
        {
            this.groupBoxStatus.Controls.Add(progressBar);
        }