介绍
CheckBox控件是用来开启选项(true)或关闭(false)。每个复选框标签代表的复选框做什么。通过点击它可以改变一个复选框的状态。
类的声明
以下是声明的java.awt.Checkbox类:
public class Checkbox extends Component implements ItemSelectable,Accessible
类的构造函数
| S.N. | 构造函数与说明 | 
|---|---|
| 1 | Checkbox() Creates a check box with an empty string for its label. | 
| 2 | Checkbox(String label) Creates a check box with the specified label. | 
| 3 | Checkbox(String label, boolean state) Creates a check box with the specified label and sets the specified state. | 
| 4 | Checkbox(String label, boolean state, CheckboxGroup group) Constructs a Checkbox with the specified label, set to the specified state, and in the specified check box group. | 
| 5 | Checkbox(String label, CheckboxGroup group, boolean state) Creates a check box with the specified label, in the specified check box group, and set to the specified state. | 
类方法
| S.N. | 方法和说明 | 
|---|---|
| 1 | void addItemListener(ItemListener l) Adds the specified item listener to receive item events from this check box. | 
| 2 | void addNotify() Creates the peer of the Checkbox. | 
| 3 | AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this Checkbox. | 
| 4 | CheckboxGroup getCheckboxGroup() Determines this check box's group. | 
| 5 | ItemListener[] getItemListeners() Returns an array of all the item listeners registered on this checkbox. | 
| 6 | String getLabel() Gets the label of this check box. | 
| 7 | <T extends EventListener>T[] getListeners(Class<T> listenerType) Returns an array of all the objects currently registered as FooListeners upon this Checkbox. | 
| 8 | Object[] getSelectedObjects() Returns an array (length 1) containing the checkbox label or null if the checkbox is not selected. | 
| 9 | boolean getState() Determines whether this check box is in the on or off state. | 
| 10 | protected String paramString() Returns a string representing the state of this Checkbox. | 
| 11 | protected void processEvent(AWTEvent e) Processes events on this check box. | 
| 12 | protected void processItemEvent(ItemEvent e) Processes item events occurring on this check box by dispatching them to any registered ItemListener objects. | 
| 13 | void removeItemListener(ItemListener l) Removes the specified item listener so that the item listener no longer receives item events from this check box. | 
| 14 | void setCheckboxGroup(CheckboxGroup g) Sets this check box's group to the specified check box group. | 
| 15 | void setLabel(String label) Sets this check box's label to be the string argument. | 
| 16 | void setState(boolean state) Sets the state of this check box to the specified state. | 
继承的方法
这个类继承的方法从以下类:
- 
		java.awt.Component 
- 
		java.lang.Object 
CheckBox的示例
说在您选择使用的编辑器创建以下java程序 D:/ > AWT > com > xuhuhu.com > gui >
AwtControlDemo.javapackage com.zaixian.gui; import java.awt.*; import java.awt.event.*; public class AwtControlDemo { private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; public AwtControlDemo(){ prepareGUI(); } public static void main(String[] args){ AwtControlDemo awtControlDemo = new AwtControlDemo(); awtControlDemo.showCheckBoxDemo(); } private void prepareGUI(){ mainFrame = new Frame("Java AWT Examples"); mainFrame.setSize(400,400); mainFrame.setLayout(new GridLayout(3, 1)); mainFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent windowEvent){ System.exit(0); } }); headerLabel = new Label(); headerLabel.setAlignment(Label.CENTER); statusLabel = new Label(); statusLabel.setAlignment(Label.CENTER); statusLabel.setSize(350,100); controlPanel = new Panel(); controlPanel.setLayout(new FlowLayout()); mainFrame.add(headerLabel); mainFrame.add(controlPanel); mainFrame.add(statusLabel); mainFrame.setVisible(true); } private void showCheckBoxDemo(){ headerLabel.setText("Control in action: CheckBox"); Checkbox chkApple = new Checkbox("Apple"); Checkbox chkMango = new Checkbox("Mango"); Checkbox chkPeer = new Checkbox("Peer"); chkApple.addItemListener(new ItemListener() { public void itemStateChanged(ItemEvent e) { statusLabel.setText("Apple Checkbox: " + (e.getStateChange()==1?"checked":"unchecked")); } }); chkMango.addItemListener(new ItemListener() { public void itemStateChanged(ItemEvent e) { statusLabel.setText("Mango Checkbox: " + (e.getStateChange()==1?"checked":"unchecked")); } }); chkPeer.addItemListener(new ItemListener() { public void itemStateChanged(ItemEvent e) { statusLabel.setText("Peer Checkbox: " + (e.getStateChange()==1?"checked":"unchecked")); } }); controlPanel.add(chkApple); controlPanel.add(chkMango); controlPanel.add(chkPeer); mainFrame.setVisible(true); } }
编译程序,使用命令提示符。到 D:/ > AWT 然后键入以下命令。
D:AWT>javac comzaixianguiAwtControlDemo.java
如果没有错误出现,这意味着编译成功。使用下面的命令来运行程序。
D:AWT>java com.zaixian.gui.AwtControlDemo
验证下面的输出
 
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