用鼠标拖动创建矩形，而不是绘制
我想用整个屏幕创建一个矩形。 通过使用整个屏幕，我的意思是这样的：
首先，是否可以在Java中使用整个屏幕？ 第二，我该怎么做呢？ 另一件事，我不想绘制一个实际的矩形，我想创建on，就像在新的java.awt.Rectangle 。
nb-首先要注意的是，这是使用Java 7完成的，在Java 6中创建透明窗口的方式不同，在更新10之下是不可能的（我相信）
基本上，这会创建一个透明窗口，其大小和位置可以覆盖整个虚拟屏幕（也就是说，如果您有多个屏幕，它将覆盖所有虚拟屏幕）。
然后我使用JPanel作为主要容器来捕获鼠标事件并执行绘画效果。
面板是透明的。 这允许面板（和框架）下方的任何东西保持可见。 然后我用透明的颜色涂了这个（我这样做只是为了强调事实）。
单击并拖动某个区域时，它将被暴露。
import java.awt.BorderLayout; import java.awt.Color; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GraphicsDevice; import java.awt.GraphicsEnvironment; import java.awt.Point; import java.awt.Rectangle; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.geom.Area; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class MySnipTool { public static void main(String[] args) { new MySnipTool(); } public MySnipTool() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Testing"); frame.setUndecorated(true); frame.setBackground(new Color(0, 0, 0, 0)); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new CapturePane()); Rectangle bounds = getVirtualBounds(); frame.setLocation(bounds.getLocation()); frame.setSize(bounds.getSize()); frame.setAlwaysOnTop(true); frame.setVisible(true); } }); } public class CapturePane extends JPanel { private Rectangle selectionBounds; private Point clickPoint; public CapturePane() { setOpaque(false); MouseAdapter mouseHandler = new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e) && e.getClickCount() == 2) { System.exit(0); } } @Override public void mousePressed(MouseEvent e) { clickPoint = e.getPoint(); selectionBounds = null; } @Override public void mouseReleased(MouseEvent e) { clickPoint = null; } @Override public void mouseDragged(MouseEvent e) { Point dragPoint = e.getPoint(); int x = Math.min(clickPoint.x, dragPoint.x); int y = Math.min(clickPoint.y, dragPoint.y); int width = Math.max(clickPoint.x - dragPoint.x, dragPoint.x - clickPoint.x); int height = Math.max(clickPoint.y - dragPoint.y, dragPoint.y - clickPoint.y); selectionBounds = new Rectangle(x, y, width, height); repaint(); } }; addMouseListener(mouseHandler); addMouseMotionListener(mouseHandler); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g.create(); g2d.setColor(new Color(255, 255, 255, 128)); Area fill = new Area(new Rectangle(new Point(0, 0), getSize())); if (selectionBounds != null) { fill.subtract(new Area(selectionBounds)); } g2d.fill(fill); if (selectionBounds != null) { g2d.setColor(Color.BLACK); g2d.draw(selectionBounds); } g2d.dispose(); } } public static Rectangle getVirtualBounds() { Rectangle bounds = new Rectangle(0, 0, 0, 0); GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); GraphicsDevice lstGDs[] = ge.getScreenDevices(); for (GraphicsDevice gd : lstGDs) { bounds.add(gd.getDefaultConfiguration().getBounds()); } return bounds; } }
同样，您可以创建一个用户可以resize的透明框架。 您将负责自己实施所有resize的代码，但解决方案仍然是可行的。
更新
您可能还需要检查操作系统/硬件是否可以支持透明度…
GraphicsConfiguration config = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration(); if (!AWTUtilities.isTranslucencyCapable(config)) { System.out.println("Transluceny is not supported"); } if (!AWTUtilities.isTranslucencySupported(AWTUtilities.Translucency.PERPIXEL_TRANSPARENT)) { System.out.println("PerPeixel Transparency is not supported"); }
更新了替代方法
这是解决问题的另一种方法。 基本上它需要快速拍摄屏幕并将其渲染到窗口。 这样我们就可以根据需要控制突出显示/选择。
这样做的缺点是它是一个静态结果，你不会得到任何当前正在运行的动画效果。
import java.awt.AWTException; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GraphicsDevice; import java.awt.GraphicsEnvironment; import java.awt.HeadlessException; import java.awt.Point; import java.awt.Rectangle; import java.awt.Robot; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.image.BufferedImage; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class SnipWithScreenShoot { public static void main(String[] args) { new SnipWithScreenShoot(); } public SnipWithScreenShoot() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } try { JFrame frame = new JFrame("Test"); frame.setUndecorated(true); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new TestPane()); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } catch (AWTException exp) { exp.printStackTrace(); System.out.println("That sucks"); } } }); } public class TestPane extends JPanel { private BufferedImage image; private Rectangle selection; public TestPane() throws AWTException { Robot bot = new Robot(); image = bot.createScreenCapture(getVirtualBounds()); MouseAdapter handler = new MouseAdapter() { @Override public void mousePressed(MouseEvent e) { selection = new Rectangle(e.getPoint()); repaint(); } @Override public void mouseDragged(MouseEvent e) { Point p = e.getPoint(); int width = Math.max(selection.x - e.getX(), e.getX() - selection.x); int height = Math.max(selection.y - e.getY(), e.getY() - selection.y); selection.setSize(width, height); repaint(); } }; addMouseListener(handler); addMouseMotionListener(handler); } @Override public Dimension getPreferredSize() { return image == null ? super.getPreferredSize() : new Dimension(image.getWidth(), image.getHeight()); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); if (image != null) { Graphics2D g2d = (Graphics2D) g.create(); g2d.drawImage(image, WIDTH, 0, this); if (selection != null) { g2d.setColor(new Color(225, 225, 255, 128)); g2d.fill(selection); g2d.setColor(Color.GRAY); g2d.draw(selection); } g2d.dispose(); } } } public static Rectangle getVirtualBounds() { Rectangle bounds = new Rectangle(0, 0, 0, 0); GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment(); GraphicsDevice lstGDs[] = ge.getScreenDevices(); for (GraphicsDevice gd : lstGDs) { bounds.add(gd.getDefaultConfiguration().getBounds()); } return bounds; } }
你可以考虑创建一个透明的全屏JFrame。但这不是一个理想的技术。
您可以查看此内容 ，以便开始使用真正的解决方案。