我有一個類:超級構造函數不能正常工作如何,我認爲它應該
public abstract class LogicGate extends JPanel implements PropertyChangeListener {
private Image image;
private URL url;
private OutputTerminal output;
private Terminal input0;
private Terminal input1;
public LogicGate(String fileName) {
this.url = getClass().getResource(fileName);
this.image = new javax.swing.ImageIcon(url).getImage();
this.setSize(image.getWidth(null), image.getHeight(null));
this.output = new OutputTerminal();
}
}
和子類:
public class ANDGate extends LogicGate {
private OutputTerminal output;
private Terminal input0;
private Terminal input1;
public ANDGate() {
super("images/AND.gif");
System.out.println(this.output);
}
}
然而,當我調用一個新的ANDGate
對象,output
爲空,當它應該已經分配了(按照超級構造函數)。
現在很清楚,我在理解子類的構造函數時做了一個假設;我究竟做錯了什麼?
那麼這一切固定。感謝:D –