Java JTextField和图形图像不工作

所以我有下面的代码，每当我按下square工具按钮时，它应该在JTextFields所说的地方画一个正方形。但由于某些原因，JTextField值不起作用，并且无法绘制正方形。。。这是平方码和JTextField：

JTextFields的初始化

        squareX = new JTextField(3);
        squareY = new JTextField(3);
        squareW = new JTextField(3);
        squareH = new JTextField(3);

ActionListeners：

        squareX.addActionListener(listener);
        squareY.addActionListener(listener);
        squareW.addActionListener(listener);
        squareH.addActionListener(listener);

在这里，我将它们的值设置为文本：

        x = Integer.parseInt(op.squareX.getText());
        y = Integer.parseInt(op.squareY.getText());
        w = Integer.parseInt(op.squareW.getText());
        h = Integer.parseInt(op.squareH.getText());
        g.fillRect(x,y,w,h);

如果这里重要的是错误所说的话

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.Integer.parseInt(Integer.java:470)
    at java.lang.Integer.parseInt(Integer.java:499)
    at com.theDevCorner.Game$GridPane.paintComponent(Game.java:155)
    at javax.swing.JComponent.paint(JComponent.java:1037)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5106)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4890)
    at javax.swing.RepaintManager$3.run(RepaintManager.java:814)
    at javax.swing.RepaintManager$3.run(RepaintManager.java:802)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:802)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:745)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:725)
    at javax.swing.RepaintManager.access$1000(RepaintManager.java:46)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1684)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:708)
    at java.awt.EventQueue.access$400(EventQueue.java:82)
    at java.awt.EventQueue$2.run(EventQueue.java:669)
    at java.awt.EventQueue$2.run(EventQueue.java:667)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:678)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

构造函数JTextFieldint指定列数而不是初始值。因此，当传递给IntegerparseInt时，JTextComponent的文本值仍然为空。因此，您可以使用指定初始值的构造函数：

squareX = new JTextField("3");
squareY = new JTextField("3");
squareW = new JTextField("3");
squareH = new JTextField("3");

构造函数JTextFieldint指定列数而不是初始值。因此，当传递给IntegerparseInt时，JTextComponent的文本值仍然为空。因此，您可以使用指定初始值的构造函数：

squareX = new JTextField("3");
squareY = new JTextField("3");
squareW = new JTextField("3");
squareH = new JTextField("3");

---

非常感谢。但我也想知道是否有一种方法，我可以在文本框中输入一个值，并在按enter键时更改它。我应该打电话到什么地方重新粉刷吗@Reimusy您已经有了一个ActionListener，您可以使用它来更改值，也可以使用它来调用RepaintaltNative您可以使用或将用户输入限制为仅数值谢谢！但我也想知道是否有一种方法，我可以在文本框中输入一个值，并在按enter键时更改它。我应该打电话到什么地方重新粉刷吗@Reimusy您已经有了一个ActionListener，您可以使用它来更改值，也可以使用它来调用RepaintaltNative。您可以使用或将用户输入限制为仅数值