在Swing中添加ActionEvent [英] Add ActionEvent in Swing
本文介绍了在Swing中添加ActionEvent的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
类ImageComponent继承JComponent
实现MouseListener，MouseMotionListener {
private final BufferedImage img;
私人点p1，p2;
$ b $ public ImageComponent（File file）throws IOException {
img = ImageIO.read（file）;
setPreferredSize（new Dimension（img.getWidth（），img.getHeight（）））;
addMouseListener（this）;
addMouseMotionListener（this）;
}
@Override protected void paintComponent（Graphics g）{
super.paintComponent（g）;
g.drawImage（img，0，0，img.getWidth（），img.getHeight（），this）;
if（p1！= null&& p2！= null）
g.drawLine（p1.x，p1.y，p2.x，p2.y）;
}
@Override public void mousePressed（MouseEvent e）{
p1 = e.getPoint（）;
}
@Override public void mouseDragged（MouseEvent e）{
mouseReleased（e）;
}
@Override public void mouseReleased（MouseEvent e）{
p2 = e.getPoint（）;
repaint（）;
}
@Override public void mouseMoved（MouseEvent e）{}
@Override public void mouseClicked（MouseEvent e）{}
@Override public void mouseEntered（MouseEvent e）{}
@Override public void mouseExited（MouseEvent e）{}
public static void main（String [] args）throws Exception {
JFileChooser chooser = new JFileChooser ）;
chooser.setCurrentDirectory（new File（））;
chooser.showOpenDialog（new JFrame（））;
文件文件= chooser.getSelectedFile（）;
final ImageComponent image = new ImageComponent（file）;
JFrame frame = new JFrame（Test）;
frame.add（new JScrollPane（image））;
frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
frame.setSize（400，300）;
frame.setVisible（true）;
$ b $ p
$ b 在这段代码中，它使用 JFileChooser 直接。
现在我想添加一个按钮，当我点击它时，它应该生成一个 ActionEvent 并且应该打开一个 JFileChooser 从中我可以选择一个文件，然后它应该在框架上显示我的图像。我怎样才能做到这一点？
我创建了类似的东西
JButton open_button = new JButton（Add File）;
open_button.addActionListener（new ActionListener（）{
public void actionPerformed（ActionEvent e）{
try {
JFileChooser chooser = new JFileChooser（）;
chooser.setCurrentDirectory （new File（。））;
chooser.showOpenDialog（new JFrame（））;
File file = chooser.getSelectedFile（）;
ImageComponent image = new ImageComponent（file）;
$ b} catch（IOException ex）{
JOptionPane.showMessageDialog（null，IOException Occured）;
}
}
但它不工作..
解决方案此答案仅供参考（请参阅原始问题/答案）：
public static void main（String [] args）{
final JFrame fram e =新的JFrame（Test）;
final ImageComponent imageComponent = new ImageComponent（）;
$ b frame.add（new JButton（new AbstractAction（Load）{
@Override
public void actionPerformed（ActionEvent e）{
JFileChooser c = new JFileChooser （new File（。））;
if（c.showOpenDialog（frame）== JFileChooser.APPROVE_OPTION）{
try {
imageComponent.set（ImageIO.read（c.getSelectedFile （））;
} catch（IOException e1）{
e1.printStackTrace（）;
}
}
}
}），BorderLayout。北）;
frame.add（new JScrollPane（imageComponent），BorderLayout.CENTER）;
frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
frame.setSize（400，300）;
frame.setVisible（true）;
}
和 ImageComponent ：
static class ImageComponent extends JComponent
实现MouseListener，MouseMotionListener {
BufferedImage img;
Point p1，p2;
public ImageComponent（）{
addMouseListener（this）; addMouseMotionListener（本）;
}
public void set（BufferedImage img）{
this.img = img;
setPreferredSize（new Dimension（img.getWidth（），img.getHeight（）））;
repaint（）;
}
@Override protected void paintComponent（Graphics g）{
super.paintComponent（g）;
if（img！= null）
g.drawImage（img，0，0，img.getWidth（），img.getHeight（），this）;
if（p1！= null&& p2！= null）
g.drawLine（p1.x，p1.y，p2.x，p2.y）;
}
@Override public void mousePressed（MouseEvent e）{
p1 = e.getPoint（）;
}
@Override public void mouseDragged（MouseEvent e）{
mouseReleased（e）;
}
@Override public void mouseReleased（MouseEvent e）{
p2 = e.getPoint（）;
repaint（）;
}
@Override public void mouseMoved（MouseEvent e）{}
@Override public void mouseClicked（MouseEvent e）{}
@Override public void mouseEntered（MouseEvent e）{}
@Override public void mouseExited（MouseEvent e）{}
}
class ImageComponent extends JComponent
implements MouseListener, MouseMotionListener {
private final BufferedImage img;
private Point p1, p2;
public ImageComponent(File file) throws IOException {
img = ImageIO.read(file);
setPreferredSize(new Dimension(img.getWidth(), img.getHeight()));
addMouseListener(this);
addMouseMotionListener(this);
}
@Override protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, img.getWidth(), img.getHeight(), this);
if (p1 != null && p2 != null)
g.drawLine(p1.x, p1.y, p2.x, p2.y);
}
@Override public void mousePressed(MouseEvent e) {
p1 = e.getPoint();
}
@Override public void mouseDragged(MouseEvent e) {
mouseReleased(e);
}
@Override public void mouseReleased(MouseEvent e) {
p2 = e.getPoint();
repaint();
}
@Override public void mouseMoved(MouseEvent e) {}
@Override public void mouseClicked(MouseEvent e) {}
@Override public void mouseEntered(MouseEvent e) {}
@Override public void mouseExited(MouseEvent e) {}
public static void main(String[] args) throws Exception {
JFileChooser chooser=new JFileChooser();
chooser.setCurrentDirectory(new File(" "));
chooser.showOpenDialog(new JFrame());
File file=chooser.getSelectedFile();
final ImageComponent image = new ImageComponent(file);
JFrame frame = new JFrame("Test");
frame.add(new JScrollPane(image));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
frame.setVisible(true);
}
}
Here in this code, it takes a file using JFileChooser directly.
Now i want to add a button on which when i click, it should generates an ActionEvent and should open a JFileChooser from which i can choose a file and then it should show me that image on frame. How can i do that?
I Have created something like that
JButton open_button=new JButton("Add File");
open_button.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
try {
JFileChooser chooser = new JFileChooser();
chooser.setCurrentDirectory(new File("."));
chooser.showOpenDialog(new JFrame());
File file = chooser.getSelectedFile();
ImageComponent image=new ImageComponent(file);
} catch (IOException ex) {
JOptionPane.showMessageDialog(null, "IOException Occured");
}
}
But it isn't working..
解决方案 This answer is just for reference (see the original question/answer):
public static void main(String[] args) {
final JFrame frame = new JFrame("Test");
final ImageComponent imageComponent = new ImageComponent();
frame.add(new JButton(new AbstractAction("Load") {
@Override
public void actionPerformed(ActionEvent e) {
JFileChooser c = new JFileChooser(new File("."));
if (c.showOpenDialog(frame) == JFileChooser.APPROVE_OPTION) {
try {
imageComponent.set(ImageIO.read(c.getSelectedFile()));
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}), BorderLayout.NORTH);
frame.add(new JScrollPane(imageComponent), BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 300);
frame.setVisible(true);
}
And the ImageComponent:
static class ImageComponent extends JComponent
implements MouseListener, MouseMotionListener {
BufferedImage img;
Point p1, p2;
public ImageComponent() {
addMouseListener(this); addMouseMotionListener(this);
}
public void set(BufferedImage img) {
this.img = img;
setPreferredSize(new Dimension(img.getWidth(), img.getHeight()));
repaint();
}
@Override protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null)
g.drawImage(img, 0, 0, img.getWidth(), img.getHeight(), this);
if (p1 != null && p2 != null)
g.drawLine(p1.x, p1.y, p2.x, p2.y);
}
@Override public void mousePressed(MouseEvent e) {
p1 = e.getPoint();
}
@Override public void mouseDragged(MouseEvent e) {
mouseReleased(e);
}
@Override public void mouseReleased(MouseEvent e) {
p2 = e.getPoint();
repaint();
}
@Override public void mouseMoved(MouseEvent e) {}
@Override public void mouseClicked(MouseEvent e) {}
@Override public void mouseEntered(MouseEvent e) {}
@Override public void mouseExited(MouseEvent e) {}
}
这篇关于在Swing中添加ActionEvent的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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