Question

我试图从JTextField获取所选文本。我找到了.getHighlighter（）函数，它可以工作。我得到了所需的文本，但它不断抛出和索引越界异常。谁能告诉我为什么？

PS：我还试过检查h！= null和h [0]！= null。结果相同。

private void jTextField1MouseDragged(java.awt.event.MouseEvent evt) {                                         
    Highlight[] h = jTextField1.getHighlighter().getHighlights();
    jLabel2.setText("Selected text: " + jTextField1.getText().substring(h[0].getStartOffset(), h[0].getEndOffset()));
}

例外：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0
at interfacesprueba1.Ej3b.jTextField1MouseDragged(Ej3b.java:110)
at interfacesprueba1.Ej3b.access$000(Ej3b.java:14)
at interfacesprueba1.Ej3b$1.mouseDragged(Ej3b.java:42)
at java.awt.AWTEventMulticaster.mouseDragged(AWTEventMulticaster.java:320)
at java.awt.Component.processMouseMotionEvent(Component.java:6583)
at javax.swing.JComponent.processMouseMotionEvent(JComponent.java:3342)
at java.awt.Component.processEvent(Component.java:6304)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4891)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4542)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2750)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

Answer 1

你需要像这样检查数组长度

private void jTextField1MouseDragged(java.awt.event.MouseEvent evt) {
        Highlight[] h = jTextField1.getHighlighter().getHighlights();
        if (h != null && h.length > 0) {
            jLabel2.setText(
                    "Selected text: " + jTextField1.getText().substring(h[0].getStartOffset(), h[0].getEndOffset()));
        }
    }

使用荧光笔的java.lang.ArrayIndexOutOfBoundsException

1 个答案: