Java AWT：JFrame SetLocation 不应移出屏幕
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【中文标题】Java AWT：JFrame SetLocation 不应移出屏幕【英文标题】：Java AWT: JFrame SetLocation should not move outside the screen 【发布时间】：2021-12-10 01:57:37 【问题描述】：使用四个按钮，窗口应向四个方向（北、南、东、西）移动，并且窗口不应离开屏幕。这在北部和西部都可以顺利运行，但不幸的是，在其他方向上则不然。我猜错误是在getEffectiveScreenArea 方法中，但我不确定。
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class MoveWindowGUI extends JFrame
private JButton moveUp, moveDown, moveLeft, moveRight;
private int x, y;
public MoveWindowGUI(String title)
super(title);
this.initializeButtons();
this.prepareWindow();
this.addActionListener();
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
private void initializeButtons()
this.moveUp = new JButton("U");
this.moveDown = new JButton("D");
this.moveLeft = new JButton("L");
this.moveRight = new JButton("R");
private void prepareWindow()
setLayout(new BorderLayout(25, 25));
this.addComponents();
this.centerWindow();
setSize(300, 300);
private void centerWindow()
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Dimension windowSize = getSize();
int centralWidth = (screenSize.width - windowSize.width) / 2;
int centralHeight = (screenSize.height - windowSize.height) / 2;
setLocation(centralWidth, centralHeight);
private void addComponents()
add(this.moveUp, BorderLayout.NORTH);
add(this.moveDown, BorderLayout.SOUTH);
add(this.moveLeft, BorderLayout.WEST);
add(this.moveRight, BorderLayout.EAST);
private void addActionListener()
ActionListener listener = new WindowActionListener();
moveUp.addActionListener(listener);
moveDown.addActionListener(listener);
moveLeft.addActionListener(listener);
moveRight.addActionListener(listener);
class WindowActionListener implements ActionListener
@Override
public void actionPerformed(ActionEvent e)
String command = e.getActionCommand();
if (command.equals("U"))
y -= 10;
else if (command.equals("D"))
y += 10;
else if (command.equals("L"))
x -= 10;
else if (command.equals("R"))
x += 10;
this.refreshWindow();
private void refreshWindow()
Point lastLocation = getLocation();
Rectangle effectiveScreenArea = getEffectiveScreenArea();
int newX = lastLocation.x + x;
int newY = lastLocation.y + y;
if (newX < effectiveScreenArea.x)
newX = effectiveScreenArea.x;
else if (newY < effectiveScreenArea.y)
newY = effectiveScreenArea.y;
else if (newX >= effectiveScreenArea.width)
newX = effectiveScreenArea.width;
else if (newY >= effectiveScreenArea.height)
newY = effectiveScreenArea.height;
setLocation(newX, newY);
this.resetHeightAndWitdhLocally();
pack();
public Rectangle getEffectiveScreenArea()
int minX = 0, minY = 0, maxX = 0, maxY = 0;
GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
int screenDevices = environment.getScreenDevices().length;
for(GraphicsDevice device : environment.getScreenDevices())
Rectangle bounds = device.getDefaultConfiguration().getBounds();
minX = Math.min(minX, bounds.x);
minY = Math.min(minY, bounds.y);
maxX = Math.max(maxX, bounds.x + bounds.width);
maxY = Math.max(maxY, bounds.y + bounds.height);
return new Rectangle(minX, minY, (maxX - minX) / screenDevices, (maxY - minY) / screenDevices);
/*
private Rectangle getEffectiveScreenArea()
GraphicsConfiguration graphicsConfiguration = getGraphicsConfiguration();
Rectangle bounds = graphicsConfiguration.getBounds();
Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets(graphicsConfiguration);
Rectangle effectiveScreenArea = new Rectangle();
effectiveScreenArea.x = bounds.x + screenInsets.left;
effectiveScreenArea.y = bounds.y + screenInsets.top;
effectiveScreenArea.height = bounds.height + screenInsets.top - screenInsets.bottom;
effectiveScreenArea.width = bounds.width - screenInsets.left - screenInsets.right;
return effectiveScreenArea;
*/
private void resetHeightAndWitdhLocally()
x = 0;
y = 0;
【问题讨论】：
您没有在refreshWindow 方法中考虑窗口大小。
【参考方案1】：
我使用了您的代码并对其进行了一些修改。这是我创建的 GUI。
我将JButtons 放在JPanel 上。然后我将JPanel 放在JFrame 上。一般来说，最好将 Swing 组件放在 JPanel 上，而不是直接放在 JFrame 上。
我清理了WindowActionListener 类。
这是完整的可运行代码。我将WindowActionListener 类设为内部类，因此我可以将此代码作为一个块发布。
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MoveWindowGUI implements Runnable
public static void main(String[] args)
SwingUtilities.invokeLater(new MoveWindowGUI());
private JFrame frame;
@Override
public void run()
frame = new JFrame("Move Window GUI");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createMainPanel(), BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
private JPanel createMainPanel()
JPanel panel = new JPanel(new BorderLayout());
panel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
WindowActionListener listener = new WindowActionListener(this);
JButton upButton = new JButton("Up");
upButton.addActionListener(listener);
panel.add(upButton, BorderLayout.NORTH);
JButton downButton = new JButton("Down");
downButton.addActionListener(listener);
panel.add(downButton, BorderLayout.SOUTH);
JButton leftButton = new JButton("Left");
leftButton.addActionListener(listener);
panel.add(leftButton, BorderLayout.WEST);
JButton rightButton = new JButton("Right");
rightButton.addActionListener(listener);
panel.add(rightButton, BorderLayout.EAST);
Dimension d = panel.getPreferredSize();
d.width = 300;
panel.setPreferredSize(d);
return panel;
public JFrame getFrame()
return frame;
public class WindowActionListener implements ActionListener
private final MoveWindowGUI view;
public WindowActionListener(MoveWindowGUI view)
this.view = view;
@Override
public void actionPerformed(ActionEvent event)
String command = event.getActionCommand();
int increment = 100;
switch (command)
case "Up":
refreshWindow(0, -increment);
break;
case "Down":
refreshWindow(0, increment);
break;
case "Left":
refreshWindow(-increment, 0);
break;
case "Right":
refreshWindow(increment, 0);
break;
private void refreshWindow(int deltaX, int deltaY)
Rectangle frameArea = view.getFrame().getBounds();
Rectangle screenArea = getEffectiveScreenArea();
int x = frameArea.x;
int y = frameArea.y;
int minX = screenArea.x;
int minY = screenArea.y;
int maxX = screenArea.width - frameArea.width;
int maxY = screenArea.height - frameArea.height;
x += deltaX;
y += deltaY;
x = Math.max(minX, x);
x = Math.min(maxX, x);
y = Math.max(minY, y);
y = Math.min(maxY, y);
view.getFrame().setBounds(new Rectangle(x, y, frameArea.width, frameArea.height));
private Rectangle getEffectiveScreenArea()
int minX = 0, minY = 0, maxX = 0, maxY = 0;
GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
int screenDevices = environment.getScreenDevices().length;
for (GraphicsDevice device : environment.getScreenDevices())
Rectangle bounds = device.getDefaultConfiguration().getBounds();
minX = Math.min(minX, bounds.x);
minY = Math.min(minY, bounds.y);
maxX = Math.max(maxX, bounds.x + bounds.width);
maxY = Math.max(maxY, bounds.y + bounds.height);
return new Rectangle(minX, minY, (maxX - minX) / screenDevices,
(maxY - minY) / screenDevices);
【讨论】：
我删除了 getEffectiveScreenArea 中 screenDevices 对值 (maxY - minY) 的除法，现在它几乎可以完美运行了。以上是关于Java AWT：JFrame SetLocation 不应移出屏幕的主要内容，如果未能解决你的问题，请参考以下文章
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