为什么我的启动画面没有显示出来？

Question

我想用下面列出的图像显示启动屏幕十秒钟。我以前从未使用过splashScreen，所以我不确定它是如何工作的。

问：如何使SplashScreen显示.jpg？

代码：

import java.awt.*; 
import java.awt.event.*; 

public class SplashDemo extends JFrame { 
    private static final long serialVersionUID = 1L; 

    public SplashDemo() { 
     super("SplashScreen demo"); 
     setSize(300, 200); 
     setLayout(new BorderLayout()); 

     final SplashScreen splash = SplashScreen.getSplashScreen(); 

     if (splash == null) { 
      System.out.println("SplashScreen.getSplashScreen() returned null"); 
      return; 
     } 

     Graphics2D g = splash.createGraphics(); 

     if (g == null) { 
      System.out.println("g is null"); 
      return; 
     } 

     for(int i=0; i<100; i++) { 
      renderSplashFrame(g, i); 
      splash.update(); 
      try { 
       Thread.sleep(90); 
      } 
      catch(InterruptedException e) { 
      } 
     } 

     splash.close(); 
     setVisible(true); 
    } 

    public static void main (String args[]) { 
     SplashDemo test = new SplashDemo(); 
    } 
} 

新的代码在这里：

import java.awt.*; 
import java.awt.event.*; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.IOException; 
import javax.imageio.ImageIO; 

public class SplashDemo extends Frame implements ActionListener { 
    private static final long serialVersionUID = 1L; 

    static void renderSplashFrame(Graphics2D g, int frame) { 
     g.setComposite(AlphaComposite.Clear); 
     g.fillRect(120,140,200,40); 
     g.setPaintMode(); 
     g.setColor(Color.BLACK); 
    } 

    public SplashDemo() throws IOException { 
     super("SplashScreen demo"); 
     setSize(300, 200); 
     setLayout(new BorderLayout()); 
     final SplashScreen splash = SplashScreen.getSplashScreen(); 

     if (splash == null) { 
      System.out.println("SplashScreen.getSplashScreen() returned null"); 
      return; 
     } 

     Graphics2D g = splash.createGraphics(); 
     BufferedImage img = ImageIO.read(new File("splash.gif")); 
     g.drawImage(img, 0, 0, null); 

     for(int i=0; i<100; i++) { 
      renderSplashFrame(g, i); 
      splash.update(); 
      try { 
       Thread.sleep(90); 
      } 
      catch(InterruptedException e) { 
      } 
     } 

     splash.close(); 
     setVisible(true); 
     toFront(); 
    } 

    public void actionPerformed(ActionEvent ae) { 
     System.exit(0); 
    } 
} 

这是我的新代码。该代码运行并显示给控制台，但不会在屏幕上显示任何内容。在代码中是否有我缺少的东西？我想让启动画面显示一段时间。

新代码：这恰好是在Oracle的网站（现在还没有显示任何）

import java.awt.*; 
import java.awt.event.*; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.IOException; 

import javax.imageio.ImageIO; 

public class SplashDemoTest extends Frame implements ActionListener { 
    static void renderSplashFrame(Graphics2D g, int frame) { 
     final String[] comps = {"foo", "bar", "baz"}; 
     g.setComposite(AlphaComposite.Clear); 
     g.fillRect(120,140,200,40); 
     g.setPaintMode(); 
     g.setColor(Color.BLACK); 
     g.drawString("Loading "+comps[(frame/5)%3]+"...", 120, 150); 
    } 
    public SplashDemoTest() { 
     super("SplashScreen demo"); 
     setSize(300, 200); 
     setLayout(new BorderLayout()); 
     Menu m1 = new Menu("File"); 
     MenuItem mi1 = new MenuItem("Exit"); 
     m1.add(mi1); 
     mi1.addActionListener(this); 
     this.addWindowListener(closeWindow); 

     MenuBar mb = new MenuBar(); 
     setMenuBar(mb); 
     mb.add(m1); 
     final SplashScreen splash = SplashScreen.getSplashScreen(); 
     if (splash == null) { 
      System.out.println("SplashScreen.getSplashScreen() returned null"); 
      return; 
     } 
     Graphics2D g = splash.createGraphics(); 
     BufferedImage img; 
     try { 
      img = ImageIO.read(new File("splash.gif")); 
      g.drawImage(img, 0, 0, null); 

     } catch (IOException e1) { 
      e1.printStackTrace(); 
     } 

     if (g == null) { 
      System.out.println("g is null"); 
      return; 
     } 
     for(int i=0; i<100; i++) { 
      renderSplashFrame(g, i); 
      splash.update(); 
      try { 
       Thread.sleep(90); 
      } 
      catch(InterruptedException e) { 
      } 
     } 
     splash.close(); 
     setVisible(true); 
     toFront(); 
    } 
    public void actionPerformed(ActionEvent ae) { 
     System.exit(0); 
    } 

    private static WindowListener closeWindow = new WindowAdapter(){ 
     public void windowClosing(WindowEvent e){ 
      e.getWindow().dispose(); 
     } 
    }; 

    public static void main (String args[]) { 
     SplashDemoTest test = new SplashDemoTest(); 
    } 
} 

Answer 1

随着g.drawImage()我想是应该的，显示JPG文件。

因此在splash.createGraphics(之后），您可以使用该方法绘制图像。