ComponentListener接口

ComponentEvent類必須實現這個接口。類的對象組件註冊。使用addComponentListener（）方法，該對象可以被註冊。組件事件提出僅供參考。

接口聲明

以下是聲明的java.awt.event.ComponentListener接口：

public interface ComponentListener extends EventListener

接口中的方法

S.N.

方法＆說明

void componentHidden(ComponentEvent e)
Invoked when the component has been made invisible.

void componentMoved(ComponentEvent e)
Invoked when the component's position changes.

void componentResized(ComponentEvent e)
Invoked when the component's size changes.

void componentShown(ComponentEvent e)
Invoked when the component has been made visible.

繼承的方法

這個接口繼承的方法從下面的接口：

java.awt.EventListener

ComponentListener示例

選擇使用任何編輯器創建以下java程序 D:/ > AWT > com > yiibai > gui >

AwtListenerDemo

package com.yiibai.gui; import java.awt.*; import java.awt.event.*; public class AwtListenerDemo { private Frame mainFrame; private Label headerLabel; private Label statusLabel; private Panel controlPanel; public AwtListenerDemo(){ prepareGUI(); } public static void main(String[] args){ AwtListenerDemo awtListenerDemo = new AwtListenerDemo(); awtListenerDemo.showComponentListenerDemo(); } 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 showComponentListenerDemo(){ headerLabel.setText("Listener in action: ComponentListener"); ScrollPane panel = new ScrollPane(); panel.setBackground(Color.magenta); Label msglabel = new Label(); msglabel.setAlignment(Label.CENTER); msglabel.setText("Welcome to TutorialsPoint AWT Tutorial."); panel.add(msglabel); msglabel.addComponentListener(new CustomComponentListener()); controlPanel.add(panel); mainFrame.setVisible(true); } class CustomComponentListener implements ComponentListener { public void componentResized(ComponentEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " resized. "); } public void componentMoved(ComponentEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " moved. "); } public void componentShown(ComponentEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " shown. "); } public void componentHidden(ComponentEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " hidden. "); } } }

編譯程序，使用命令提示符。到 D:/ > AWT 然後鍵入以下命令。

D:AWT>javac comyiibaiguiAwtListenerDemo.java

如果沒有錯誤出現，這意味着編譯成功。使用下面的命令來運行程序。

D:AWT>java com.yiibai.gui.AwtListenerDemo

驗證下面的輸出

AWT