//On Click method for the dll button private void DllButton_Click(object sender, RoutedEventArgs e) { OpenFileDialog openFileDialog = new OpenFileDialog(); if (openFileDialog.ShowDialog() == true) { try { _generalVM.LoadDLLFile(openFileDialog.FileName); } catch (Exception) { filePathTextBox.Text = "Invalid dll file"; return; } filePathTextBox.Text = openFileDialog.FileName; graphs.cmbProperties.SelectedIndex = 0; playback.playBtn.Content = "Start"; playback.IsPlaying = false; } }