Java 中的启动画面
Opj*_*eey 2 java swing text splash-screen
我需要弄清楚在这段代码中我需要调整它的位置以移动“Splash Screen!!!”行 到屏幕的中间，并可能使它更大。我不确定这是在代码中的哪个位置，这让我发疯。
import java.awt.*;
import javax.swing.*;
public class SplashScreen extends JWindow {
private int duration;
public SplashScreen(int d) {
duration = d;
}
// A simple little method to show a title screen in the center
// of the screen for the amount of time given in the constructor
public void showSplash() {
JPanel content = (JPanel)getContentPane();
content.setBackground(Color.blue);
// Set the window's bounds, centering the window
int width = 700;
int height = 450;
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int x = (screen.width-width)/2;
int y = (screen.height-height)/2;
setBounds(x,y,width,height);
// Build the splash screen
JLabel label = new JLabel(new ImageIcon("java-tip.gif"));
JLabel copyrt = new JLabel
("Splash Screen!!!", JLabel.CENTER);
copyrt.setFont(new Font("Sans-Serif", Font.BOLD, 12));
content.add(label, BorderLayout.CENTER);
content.add(copyrt, BorderLayout.SOUTH);
Color oraRed = new Color(200, 50, 20, 255);
content.setBorder(BorderFactory.createLineBorder(oraRed, 10));
// Display it
setVisible(true);
// Wait a little while, maybe while loading resources
try { Thread.sleep(duration); } catch (Exception e) {}
setVisible(false);
}
public void showSplashAndExit() {
showSplash();
System.exit(0);
}
public static void main(String[] args) {
// Throw a nice little title page up on the screen first
SplashScreen splash = new SplashScreen(10000);
// Normally, we'd call splash.showSplash() and get on
// with the program. But, since this is only a test...
splash.showSplashAndExit();
}
}
我不知道为什么，但是这个论坛中的添加代码功能总是让它看起来很奇怪并且没有正确缩进。
有几种方法可以做到这一点，但让我们保持简单。
基本上，这样做是将label（背景）图像添加到内容窗格的中心位置。然后，它适用于一BorderLayout到label，并添加copyrt到的中心位置label...
public void showSplash() {
JPanel content = (JPanel) getContentPane();
content.setBackground(Color.blue);
// Set the window's bounds, centering the window
int width = 700;
int height = 450;
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int x = (screen.width - width) / 2;
int y = (screen.height - height) / 2;
setBounds(x, y, width, height);
// Build the splash screen
JLabel label = new JLabel(new ImageIcon("java-tip.gif"));
JLabel copyrt = new JLabel("Splash Screen!!!", JLabel.CENTER);
content.add(label, BorderLayout.CENTER);
// Fun starts here...
// copyrt.setFont(new Font("Sans-Serif", Font.BOLD, 12));
// content.add(copyrt, BorderLayout.SOUTH);
label.setLayout(new BorderLayout());
Font font = copyrt.getFont();
copyrt.setFont(font.deriveFont(Font.BOLD, 24f));
label.add(copyrt);
Color oraRed = new Color(200, 50, 20, 255);
content.setBorder(BorderFactory.createLineBorder(oraRed, 10));
// Display it
setVisible(true);
// Don't do this, as it will cause the EDT to be stopped. Instead
// setup some kind of callback that can tell when the resources are
// loaded and start the rest of the application from there...
// Wait a little while, maybe while loading resources
//try {
// Thread.sleep(duration);
//} catch (Exception e) {
//}
//setVisible(false);
}
在 EDT 的上下文中做任何可能阻止它处理进一步事件的事情也是一个坏主意，比如使用sleep或长时间运行/无限循环。
所有 UI 交互都应该在 EDT 的上下文中执行，并且所有长时间运行或可能阻塞的任务都应该在单独的线程上运行。
更新
如果我尝试运行您的示例，则启动画面永远不会出现，因为Thread.sleep无法在屏幕上显示。您“可能”让它工作的事实实际上是侥幸，因为您可能是showSplash从“主”线程而不是 EDT调用该方法。
相反，如果我Thread.sleep用 a替换SwingWorker，我不仅可以显示启动画面，而且还可以控制诸如进度更新和计划处理启动画面之类的额外好处......
例如...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Toolkit;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JWindow;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SplashDemo extends JWindow {
public static void main(String[] args) {
new SplashDemo();
}
public SplashDemo() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
showSplash();
}
});
}
public void showSplash() {
JPanel content = (JPanel) getContentPane();
content.setBackground(Color.blue);
// Set the window's bounds, centering the window
int width = 700;
int height = 450;
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int x = (screen.width - width) / 2;
int y = (screen.height - height) / 2;
setBounds(x, y, width, height);
// Build the splash screen
JLabel label = new JLabel(new ImageIcon(getClass().getResource("/java_animated.gif")));
JLabel copyrt = new JLabel("Splash Screen!!!", JLabel.CENTER);
content.add(label, BorderLayout.CENTER);
label.setLayout(new GridBagLayout());
Font font = copyrt.getFont();
copyrt.setFont(font.deriveFont(Font.BOLD, 24f));
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
label.add(copyrt, gbc);
ImageIcon wait = new ImageIcon(getClass().getResource("/wait.gif"));
label.add(new JLabel(wait), gbc);
Color oraRed = new Color(200, 50, 20, 255);
content.setBorder(BorderFactory.createLineBorder(oraRed, 10));
// Display it
setVisible(true);
toFront();
new ResourceLoader().execute();
}
public class ResourceLoader extends SwingWorker<Object, Object> {
@Override
protected Object doInBackground() throws Exception {
// Wait a little while, maybe while loading resources
try {
Thread.sleep(5000);
} catch (Exception e) {
}
return null;
}
@Override
protected void done() {
setVisible(false);
}
}
}
如果您愿意，我使用了以下图片...
