ContainerListener 接口

介紹

用於接收容器事件的接口ContainerListener。過程容器事件的類需要實現這個接口。

類的聲明

以下聲明是java.awt.event.ContainerListener接口：

public interface ContainerListener extends EventListener

接口中的方法

S.N.

方法＆說明

void componentAdded(ContainerEvent e)
Invoked when a component has been added to the container.

void componentRemoved(ContainerEvent e)
Invoked when a component has been removed from the container.

繼承的方法

這個類繼承的方法從下面的接口：

java.awt.event.EventListener

AdjustmentListener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.showContainerListenerDemo(); } 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 showContainerListenerDemo(){ headerLabel.setText("Listener in action: ContainerListener"); ScrollPane panel = new ScrollPane(); panel.setBackground(Color.magenta); panel.addContainerListener(new CustomContainerListener()); Label msglabel = new Label(); msglabel.setAlignment(Label.CENTER); msglabel.setText("Welcome to TutorialsPoint AWT Tutorial."); panel.add(msglabel); controlPanel.add(panel); mainFrame.setVisible(true); } class CustomContainerListener implements ContainerListener { public void componentAdded(ContainerEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " added. "); } public void componentRemoved(ContainerEvent e) { statusLabel.setText(statusLabel.getText() + e.getComponent().getClass().getSimpleName() + " removed. "); } } }

編譯程序，使用命令提示符。進入到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