private void LoadNn_Click(object sender, EventArgs e) { var dlg = new OpenFileDialog(); if (dlg.ShowDialog() == DialogResult.OK) { txtBoxNnPath.Text = dlg.FileName; if (Path.GetExtension(dlg.FileName) == ".json") { Inference inference = new Inference(); inference.LoadNeuralNetwork(dlg.FileName); Form1 f1 = new Form1(inference); Hide(); f1.Show(); } else { MessageBox.Show("File has to be a .json file"); } } }