使a java.awt.Window
(例如a JFrame
或a)居中的最简单方法是JDialog
什么?
setLocation()
,setLocationRelativeTo()
以及setLocationByPlatform()
或全部AWT,不能摇摆。;)
使a java.awt.Window
(例如a JFrame
或a)居中的最简单方法是JDialog
什么?
setLocation()
,setLocationRelativeTo()
以及setLocationByPlatform()
或全部AWT,不能摇摆。;)
Answers:
从这个连结
如果使用的是Java 1.4或更高版本,则可以在对话框,框架或窗口上使用简单的setLocationRelativeTo(null)方法将其居中。
pack()
,并将框架的左上角放在屏幕中心。将线移到下方后,将pack()
其正确居中。
这应该适用于所有版本的Java
public static void centreWindow(Window frame) {
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
frame.setLocation(x, y);
}
请注意,setLocationRelativeTo(null)和Tookit.getDefaultToolkit()。getScreenSize()技术仅适用于主监视器。如果您处于多监视器环境中,则在进行这种计算之前,可能需要获取有关窗口所在的特定监视器的信息。
有时很重要,有时不重要...
有关如何获取此信息的更多信息,请参见GraphicsEnvironment javadocs。
在Linux上的代码
setLocationRelativeTo(null)
在多显示器环境中,每次启动窗口时,请将其放置在随机位置。和代码
setLocation((Toolkit.getDefaultToolkit().getScreenSize().width - getSize().width) / 2, (Toolkit.getDefaultToolkit().getScreenSize().height - getSize().height) / 2);
将该窗口“切成两半”,并将其放置在我的两个显示器之间的确切中心。我使用以下方法将其居中:
private void setWindowPosition(JFrame window, int screen)
{
GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice[] allDevices = env.getScreenDevices();
int topLeftX, topLeftY, screenX, screenY, windowPosX, windowPosY;
if (screen < allDevices.length && screen > -1)
{
topLeftX = allDevices[screen].getDefaultConfiguration().getBounds().x;
topLeftY = allDevices[screen].getDefaultConfiguration().getBounds().y;
screenX = allDevices[screen].getDefaultConfiguration().getBounds().width;
screenY = allDevices[screen].getDefaultConfiguration().getBounds().height;
}
else
{
topLeftX = allDevices[0].getDefaultConfiguration().getBounds().x;
topLeftY = allDevices[0].getDefaultConfiguration().getBounds().y;
screenX = allDevices[0].getDefaultConfiguration().getBounds().width;
screenY = allDevices[0].getDefaultConfiguration().getBounds().height;
}
windowPosX = ((screenX - window.getWidth()) / 2) + topLeftX;
windowPosY = ((screenY - window.getHeight()) / 2) + topLeftY;
window.setLocation(windowPosX, windowPosY);
}
使窗口显示在第一个显示器的中央。这可能不是最简单的解决方案。
在Linux,Windows和Mac上正常运行。
最终,我得到了这一系列代码,以便使用Swing GUI Forms在NetBeans中工作,以便将主要jFrame居中:
package my.SampleUIdemo;
import java.awt.*;
public class classSampleUIdemo extends javax.swing.JFrame {
///
public classSampleUIdemo() {
initComponents();
CenteredFrame(this); // <--- Here ya go.
}
// ...
// void main() and other public method declarations here...
/// modular approach
public void CenteredFrame(javax.swing.JFrame objFrame){
Dimension objDimension = Toolkit.getDefaultToolkit().getScreenSize();
int iCoordX = (objDimension.width - objFrame.getWidth()) / 2;
int iCoordY = (objDimension.height - objFrame.getHeight()) / 2;
objFrame.setLocation(iCoordX, iCoordY);
}
}
要么
package my.SampleUIdemo;
import java.awt.*;
public class classSampleUIdemo extends javax.swing.JFrame {
///
public classSampleUIdemo() {
initComponents();
//------>> Insert your code here to center main jFrame.
Dimension objDimension = Toolkit.getDefaultToolkit().getScreenSize();
int iCoordX = (objDimension.width - this.getWidth()) / 2;
int iCoordY = (objDimension.height - this.getHeight()) / 2;
this.setLocation(iCoordX, iCoordY);
//------>>
}
// ...
// void main() and other public method declarations here...
}
要么
package my.SampleUIdemo;
import java.awt.*;
public class classSampleUIdemo extends javax.swing.JFrame {
///
public classSampleUIdemo() {
initComponents();
this.setLocationRelativeTo(null); // <<--- plain and simple
}
// ...
// void main() and other public method declarations here...
}
以下不适用于JDK 1.7.0.07:
frame.setLocationRelativeTo(null);
它将左上角置于中心-与将窗口居中不同。另一个也不起作用,涉及frame.getSize()和Dimension.getSize():
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
frame.setLocation(x, y);
getSize()方法是从Component类继承的,因此frame.getSize也返回窗口的大小。因此,从垂直和水平尺寸中减去垂直和水平尺寸的一半,以找到左上角放置位置的x,y坐标,即可获得中心点的位置,该点最终也将窗口居中。但是,上面代码的第一行很有用,“ Dimension ...”。只需将其居中即可:
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
JLabel emptyLabel = new JLabel("");
emptyLabel.setPreferredSize(new Dimension( (int)dimension.getWidth() / 2, (int)dimension.getHeight()/2 ));
frame.getContentPane().add(emptyLabel, BorderLayout.CENTER);
frame.setLocation((int)dimension.getWidth()/4, (int)dimension.getHeight()/4);
JLabel设置屏幕大小。它位于FrameDemo.java中,可从Oracle / Sun站点的Java教程中获得。我将其设置为屏幕尺寸的高度/宽度的一半。然后,通过将左上角放置在屏幕尺寸的左半角的1/4处,并将屏幕尺寸的大小从顶部算起的1/4角,将其居中。您可以使用类似的概念。
以下是用于在现有窗口的顶部中心显示框架的代码。
public class SwingContainerDemo {
private JFrame mainFrame;
private JPanel controlPanel;
private JLabel msglabel;
Frame.setLayout(new FlowLayout());
mainFrame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
System.exit(0);
}
});
//headerLabel = new JLabel("", JLabel.CENTER);
/* statusLabel = new JLabel("",JLabel.CENTER);
statusLabel.setSize(350,100);
*/ msglabel = new JLabel("Welcome to TutorialsPoint SWING Tutorial.", JLabel.CENTER);
controlPanel = new JPanel();
controlPanel.setLayout(new FlowLayout());
//mainFrame.add(headerLabel);
mainFrame.add(controlPanel);
// mainFrame.add(statusLabel);
mainFrame.setUndecorated(true);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.getRootPane().setWindowDecorationStyle(JRootPane.NONE);
mainFrame.setVisible(true);
centreWindow(mainFrame);
}
public static void centreWindow(Window frame) {
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
frame.setLocation(x, 0);
}
public void showJFrameDemo(){
/* headerLabel.setText("Container in action: JFrame"); */
final JFrame frame = new JFrame();
frame.setSize(300, 300);
frame.setLayout(new FlowLayout());
frame.add(msglabel);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowEvent){
frame.dispose();
}
});
JButton okButton = new JButton("Capture");
okButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// statusLabel.setText("A Frame shown to the user.");
// frame.setVisible(true);
mainFrame.setState(Frame.ICONIFIED);
Robot robot = null;
try {
robot = new Robot();
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
final Dimension screenSize = Toolkit.getDefaultToolkit().
getScreenSize();
final BufferedImage screen = robot.createScreenCapture(
new Rectangle(screenSize));
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ScreenCaptureRectangle(screen);
}
});
mainFrame.setState(Frame.NORMAL);
}
});
controlPanel.add(okButton);
mainFrame.setVisible(true);
} public static void main(String [] args)引发异常{
new SwingContainerDemo().showJFrameDemo();
}
frame.setLocation(x, 0);
似乎是错误的-应该frame.setLocation(x, y);
吗?
int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
,代码中存在的内容只是表明您也可以在垂直轴上居中?好的,我以为您只是忘了使用它,对不起造成麻烦。
示例:在第3行的myWindow()内部是将窗口设置在屏幕中央所需的代码。
JFrame window;
public myWindow() {
window = new JFrame();
window.setSize(1200,800);
window.setLocationRelativeTo(null); // this line set the window in the center of thr screen
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.getContentPane().setBackground(Color.BLACK);
window.setLayout(null); // disable the default layout to use custom one.
window.setVisible(true); // to show the window on the screen.
}
frame.setLocationRelativeTo(null);
完整示例:
public class BorderLayoutPanel {
private JFrame mainFrame;
private JButton btnLeft, btnRight, btnTop, btnBottom, btnCenter;
public BorderLayoutPanel() {
mainFrame = new JFrame("Border Layout Example");
btnLeft = new JButton("LEFT");
btnRight = new JButton("RIGHT");
btnTop = new JButton("TOP");
btnBottom = new JButton("BOTTOM");
btnCenter = new JButton("CENTER");
}
public void SetLayout() {
mainFrame.add(btnTop, BorderLayout.NORTH);
mainFrame.add(btnBottom, BorderLayout.SOUTH);
mainFrame.add(btnLeft, BorderLayout.EAST);
mainFrame.add(btnRight, BorderLayout.WEST);
mainFrame.add(btnCenter, BorderLayout.CENTER);
// mainFrame.setSize(200, 200);
// or
mainFrame.pack();
mainFrame.setVisible(true);
//take up the default look and feel specified by windows themes
mainFrame.setDefaultLookAndFeelDecorated(true);
//make the window startup position be centered
mainFrame.setLocationRelativeTo(null);
mainFrame.setDefaultCloseOperation(mainFrame.EXIT_ON_CLOSE);
}
}
以下代码Window
将居中于当前监视器的中心(即鼠标指针所在的位置)。
public static final void centerWindow(final Window window) {
GraphicsDevice screen = MouseInfo.getPointerInfo().getDevice();
Rectangle r = screen.getDefaultConfiguration().getBounds();
int x = (r.width - window.getWidth()) / 2 + r.x;
int y = (r.height - window.getHeight()) / 2 + r.y;
window.setLocation(x, y);
}
实际上是框架.getHeight()
并且getwidth()
不返回值,通过System.out.println(frame.getHeight());
直接输入宽度和高度的值来检查它,然后它将在中心正常工作。例如:如下
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x=(int)((dimension.getWidth() - 450)/2);
int y=(int)((dimension.getHeight() - 450)/2);
jf.setLocation(x, y);
450都是我的框架宽度n高度
public class SwingExample implements Runnable {
@Override
public void run() {
// Create the window
final JFrame f = new JFrame("Hello, World!");
SwingExample.centerWindow(f);
f.setPreferredSize(new Dimension(500, 250));
f.setMaximumSize(new Dimension(10000, 200));
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void centerWindow(JFrame frame) {
Insets insets = frame.getInsets();
frame.setSize(new Dimension(insets.left + insets.right + 500, insets.top + insets.bottom + 250));
frame.setVisible(true);
frame.setResizable(false);
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
frame.setLocation(x, y);
}
}