private void categoriesListBox_SelectedIndexChanged(object sender, EventArgs e) { try { // categoryLabel.Text = categoriesListBox.SelectedItem; var category = categoriesListBox.SelectedItem as CategoryModel; categoryLabel.Text = category.name; SideClass.OutputData.outputExpensesToDgv(dataGridView1, category.name); var mlrArray = SQLiter.getMLRSum(category.name); maxSumLabel.Text = mlrArray[0].ToString(); lostSumLabel.Text = mlrArray[1].ToString(); remainingSumLabel.Text = mlrArray[2].ToString(); } catch (NullReferenceException) { MessageBox.Show("f**k"); } }