Beispiel dafür, wie Java ein Systemsymbol und ein Dateisymbol basierend auf der Erweiterung erhält

复制代码代码如下:

java.io.File importieren;

import java.io.IOException;

import java.awt.BorderLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

javax.swing.Icon importieren;

import javax.swing.ImageIcon;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextField;

import javax.swing.JLabel;

import javax.swing.BoxLayout;

import javax.swing.filechooser.FileSystemView;

import sun.awt.shell.ShellFolder;

Die öffentliche Klasse FileIconExtractor erweitert JFrame und implementiert ActionListener{

privater JButton getIconBtn = new JButton("get Icon");

privates JPanel iconPanel = new JPanel();

privates JTextField extField = new JTextField();

private JLabel smallIconLabel = new JLabel("kleines Symbol hier");

private JLabel bigIconLabel = new JLabel("big Icon here");

public FileIconExtractor() {

this.setSize(200, 150);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setLayout(new BorderLayout());

getIconBtn.setActionCommand("GETICON");

getIconBtn.addActionListener(this);

iconPanel.setLayout(new BoxLayout(iconPanel, BoxLayout.Y_AXIS));

iconPanel.add(smallIconLabel);

iconPanel.add(bigIconLabel);

this.add(extField, BorderLayout.NORTH);

this.add(iconPanel, BorderLayout.CENTER);

this.add(getIconBtn, BorderLayout.SOUTH);

this.setVisible(true);

}

public void actionPerformed(ActionEvent e) {

if (e.getActionCommand().equals("GETICON")) {

String ext = extField.getText();

Dateidatei;

versuchen

{

file = File.createTempFile("icon", "." + ext);

FileSystemView view = FileSystemView.getFileSystemView();

Symbol smallIcon = view.getSystemIcon(file);

ShellFolder shellFolder = ShellFolder.getShellFolder(file);

Icon bigIcon = new ImageIcon(shellFolder.getIcon(true));

setIconLabel(smallIcon, bigIcon);

file.delete();

}

Catch (IOException ioe)

{

ioe.printStackTrace();

}

}

}

private void setIconLabel(Icon smallIcon, Icon bigIcon) {

smallIconLabel.setIcon(smallIcon);

bigIconLabel.setIcon(bigIcon);

}

public static void main(String[] args) {

FileIconExtractor fie = new FileIconExtractor();

}

}