public void ProcessArgs(string[] args, bool firstInstance) { //Process Command Line Arguments Here if (args.Length == 0) { //if no file is given via args get file from OpenFileDialog Microsoft.Win32.OpenFileDialog fileDlg = new Microsoft.Win32.OpenFileDialog(); fileDlg.DefaultExt = "vpp"; fileDlg.Filter = "VisionProFiles (*.vpp)|*.vpp"; if (!String.IsNullOrEmpty(settings.ReadValue("FileDialog", "InitialDirectory"))) { fileDlg.InitialDirectory = settings.ReadValue("FileDialog", "InitialDirectory"); } fileDlg.ShowDialog(); MyWindow.OpenVPP(fileDlg.FileName); } else if (args.Length == 1) { MyWindow.OpenVPP(args[0]); } }