private void OnAddEditContactRequestMsg(AddEditContactRequestMsg obj) { var openFileDialog = new OpenFileDialog { DefaultExt = "key", Filter = "Public Key File (*.key)| *.key" }; var dialogResult = openFileDialog.ShowDialog(); if (dialogResult != null && dialogResult.Value) { var filename = openFileDialog.FileName; _messenger.Send(new AddEditContactConfirmMsg(filename)); } }