我只是這個鞦韆的新生,所以我遇到了這個問題:JButton - 把圖像不起作用
我試圖把圖像放到我的按鈕,但每當我嘗試加,是因爲在其他條目返回此
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)
我是一個有點困惑的人說,它工作正常,但是,它成爲了我克服一個具有挑戰性的任務。你應該事先知道MainPanel
類代表框架中的面板,在MainPanel
裏面,我有輸入面板,我試圖把我的JButton
。這裏是我的代碼:
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);
}
}
編輯: 我的文件夾結構是簡單的
- 項目→
gui
(包)→images
(文件夾)這是圖像。 - 項目→
gui
(包)→MainPanel.java
(和所有其他源代碼)。
SOLUTION:文件目錄應該是像../images/input.png
。
包中是否有'MainPanel'?項目的結構是什麼(至少顯示'MainPanel'源文件和圖像的位置)? – 2015-02-24 10:17:28
'setPreferredSize(new Dimension(1400,800));'請參閱[我應該避免使用Java Swing中的set(Preferred | Maximum | Minimum)Size方法嗎?](http://stackoverflow.com/q/7229226/ 418556)(是的。)在這種情況下,我們最好查看[white space]的佈局填充和邊界(http://stackoverflow.com/a/17874718/418556),然後調用'frame.pack();' 。 – 2015-02-24 10:19:53
*「我的圖片的尺寸爲90x68」。* Riiight ..除非它適用於圖像「89x68」,而另一個則不適用於'90x68',否則我看不出相關。請回答我的前兩個問題。 – 2015-02-24 10:22:41