void OnOpen(object sender, EventArgs e) { if (String.IsNullOrEmpty(txtPath.Text)) { return; } IShellService shell = GlobalServices.Instance.GetService <IShellService>(); if (shell != null) { shell.OpenFile(txtPath.Text, btnOpen); } else { DisplayAlert("GridDemo", "Unable to open a file. The Shell service is not found.", "Cancel"); } }