importjavax.swing.*;importjava.awt.event.ActionEvent;importjava.awt.event.ActionListener;publicclassComboBoxExample{publicstaticvoidmain(String[]args){JFrameframe=newJFrame();String[]options={"选项1","选项2","选项3"};JComboBox<String>comboBox=newJComboBox<>(options);comboBox.addActionListener(...
Exceptionin thread"AWT-EventQueue-0"java.lang.NullPointerExceptionatjavax.swing.JComboBox.getSelectedItem(JComboBox.java:669) 1. 2. 这些异常经常导致应用程序崩溃或表现不稳定。通过对异常统计发现,大约 60% 的用户在使用下拉框时遭遇此错。 根因分析 通过对JComboBox的工作原理深入分析,我们发现问题的根源...
java.lang.Object java.awt.Component java.awt.Container javax.swing.JComponent javax.swing.JComboBox<E> Type Parameters: E - the type of the elements of this combo box All Implemented Interfaces: ActionListener, ImageObserver, ItemSelectable, MenuContainer, Serializable, EventListener, Accessible, ...
在Java中,可以通过以下步骤使用Combobox设置框架的标题: 1. 导入必要的类: ```java import javax.swing.*; import java.awt...
JavaSE高级之GUI编程 它规定了所有GUI组件的的的基本特性 j ava.swing 是在java.awt 的基础上构建起来的,引入了许多新的功能和新的特性 c) GUI组件 i. ...基本组件:在其控件中不能容纳其他组件,如按钮,文本框等 ii. 容器:可以在其上面添加其他组件,如窗口,对话框等; 2. ...按钮组件:JButton-...
java.lang.Object java.awt.Component java.awt.Container javax.swing.JComponent javax.swing.AbstractButton javax.swing.JButton javax.swing.plaf.metal.MetalComboBoxButton 实现的所有接口 ImageObserver, ItemSelectable, MenuContainer, Serializable, Accessible, SwingConstants public class ...
クラス java.awt.Container.AccessibleAWTContainerで宣言されたメソッド getAccessibleAt クラス java.awt.Component.AccessibleAWTComponentで宣言されたメソッド addFocusListener,contains,getAccessibleComponent,getAccessibleIndexInParent,getAccessibleParent,getBackground,getBounds,getCursor,getFont,getFontMetrics,get...
声明方法的类 java.awt.Container.AccessibleAWTContainer getAccessibleAt 声明方法的类 java.awt.Component.AccessibleAWTComponent addFocusListener, contains, getAccessibleComponent, getAccessibleIndexInParent, getAccessibleParent, getBackground, getBounds, getCursor, getFont, getFontMetrics, getForeground, getLoca...
import java.awt.F ont; import java.awt.GridLayout; importjava.awt.eve nt.ltemEve nt; import java.awt.eve nt.ItemListe ner; importjavax.sw in g.JComboBox; importjavax.swi ng.JFrame; importjavax.sw in g.JLabel; importjavax.swi ng.JOptio nPane; ...
accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW 从类继承的字段 java.awt.Component BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT ...