Errors when using GUI: IllegalStateException
问题 I keep getting errors when trying to run my program even though when making the program in net beans I have no errors. It's only when I try to compile that 50 errors pop up. Someone explained that my JTextField wasn't attached to the Horizontal group and I thought I fixed it but it seems not. public class TrianglePerimeter extends javax.swing.JFrame { public TrianglePerimeter() { utilizeComponents(); } @SuppressWarnings("Not Checked") private void utilizeComponents() { sideOneInput = new