private void SetProgressPanelVisible(Boolean isVisible) { if (!this.pnlProgress.InvokeRequired) { this.pnlProgress.Visible = isVisible; this.pnlProgress.Enabled = isVisible; } else { Panel panelControl = pnlProgress; SetProgressPanelVisibleDelegate setProgressPanelVisibleDelegate = new SetProgressPanelVisibleDelegate(SetProgressPanelVisible); Object[] objArray = new Object[] { isVisible }; panelControl.Invoke(setProgressPanelVisibleDelegate, objArray); } }