我只是这个秋千的新生,所以我遇到了这个问题:JButton - 把图像不起作用
我试图把图像放到我的按钮,但每当我尝试加,是因为在其他条目返回此
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:217)
at gui.MainPanel.<init>(MainPanel.java:45)
at gui.IntroPanel$2.actionPerformed(IntroPanel.java:62)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6527)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6292)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4883)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:719)
at java.awt.EventQueue$4.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
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)
我是一个有点困惑的人说,它工作正常,但是,它成为了我克服一个具有挑战性的任务。你应该事先知道MainPanel
类代表框架中的面板,在MainPanel
里面,我有输入面板,我试图把我的JButton
。这里是我的代码:
public class MainPanel extends JPanel {
private JPanel inputPanel;
private JButton inputButton;
public MainPanel() {
setBackground(new Color(250, 250, 250));
setPreferredSize(new Dimension(1400, 800));
setLayout(new BorderLayout());
inputPanel = new JPanel();
inputButton = new JButton(new ImageIcon(getClass().getResource("images/input.png")));
inputPanel.add(inputButton);
add(inputPanel);
}
}
编辑: 我的文件夹结构是简单的
- 项目→
gui
(包)→images
(文件夹)这是图像。 - 项目→
gui
(包)→MainPanel.java
(和所有其他源代码)。
SOLUTION:文件目录应该是像../images/input.png
。
包中是否有'MainPanel'?项目的结构是什么(至少显示'MainPanel'源文件和图像的位置)? – 2015-02-24 10:17:28
'setPreferredSize(new Dimension(1400,800));'请参阅[我应该避免使用Java Swing中的set(Preferred | Maximum | Minimum)Size方法吗?](http://stackoverflow.com/q/7229226/ 418556)(是的。)在这种情况下,我们最好查看[white space]的布局填充和边界(http://stackoverflow.com/a/17874718/418556),然后调用'frame.pack();' 。 – 2015-02-24 10:19:53
*“我的图片的尺寸为90x68”。* Riiight ..除非它适用于图像“89x68”,而另一个则不适用于'90x68',否则我看不出相关。请回答我的前两个问题。 – 2015-02-24 10:22:41