Java 右鍵彈出式菜單

Java swing 的右鍵彈出式菜單，一下是一個示例，實現了文本框的複製、粘貼、剪切。

 

 

 

import java.awt.datatransfer.Clipboard; import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.Transferable; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.InputEvent; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.JFrame; import javax.swing.JMenuItem; import javax.swing.JPopupMenu; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.KeyStroke; import javax.swing.UIManager; /** * Java右鍵菜單實現文本組件內容的的複製、粘貼、剪切功能 * */ public class Test extends JFrame { private static final long serialVersionUID = -5942087991012920147L; private JScrollPane pane = null; private TextAreaMenu text = null; public Test() { super("右鍵菜單"); try { // 使用Windows的界面風格 UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); } catch (Exception e) { e.printStackTrace(); } text = new TextAreaMenu(); pane = new JScrollPane(text); this.getContentPane().add(pane); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setSize(300, 200); this.setVisible(true); } public static void main(String args[]) { new Test(); } /** * 帶有功能菜單的JTextArea * */ class TextAreaMenu extends JTextArea implements MouseListener { private static final long serialVersionUID = -2308615404205560110L; private JPopupMenu pop = null; // 彈出菜單 private JMenuItem copy = null, paste = null, cut = null; // 三個功能菜單 public TextAreaMenu() { super(); init(); } private void init() { this.addMouseListener(this); pop = new JPopupMenu(); pop.add(copy = new JMenuItem("複製")); pop.add(paste = new JMenuItem("粘貼")); pop.add(cut = new JMenuItem("剪切")); copy.setAccelerator(KeyStroke.getKeyStroke('C', InputEvent.CTRL_MASK)); paste.setAccelerator(KeyStroke.getKeyStroke('V', InputEvent.CTRL_MASK)); cut.setAccelerator(KeyStroke.getKeyStroke('X', InputEvent.CTRL_MASK)); copy.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { action(e); } }); paste.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { action(e); } }); cut.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { action(e); } }); this.add(pop); } /** * 菜單動作 * @param e */ public void action(ActionEvent e) { String str = e.getActionCommand(); if (str.equals(copy.getText())) { // 複製 this.copy(); } else if (str.equals(paste.getText())) { // 粘貼 this.paste(); } else if (str.equals(cut.getText())) { // 剪切 this.cut(); } } public JPopupMenu getPop() { return pop; } public void setPop(JPopupMenu pop) { this.pop = pop; } /** * 剪切板中是否有文本數據可供粘貼 * * @return true爲有文本數據 */ public boolean isClipboardString() { boolean b = false; Clipboard clipboard = this.getToolkit().getSystemClipboard(); Transferable content = clipboard.getContents(this); try { if (content.getTransferData(DataFlavor.stringFlavor) instanceof String) { b = true; } } catch (Exception e) { } return b; } /** * 文本組件中是否具備複製的條件 * * @return true爲具備 */ public boolean isCanCopy() { boolean b = false; int start = this.getSelectionStart(); int end = this.getSelectionEnd(); if (start != end) b = true; return b; } public void mouseClicked(MouseEvent e) { } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } public void mousePressed(MouseEvent e) { if (e.getButton() == MouseEvent.BUTTON3) { copy.setEnabled(isCanCopy()); paste.setEnabled(isClipboardString()); cut.setEnabled(isCanCopy()); pop.show(this, e.getX(), e.getY()); } } public void mouseReleased(MouseEvent e) { } } }