我正在整理一个幻灯片程序，用于衡量用户在每张幻灯片上花费的时间。幻灯片演示了几个不同的魔术技巧。每个技巧都会显示两次。在重复之间显示临时图像。在每个技巧之间显示过渡图像。
在第一次重复播放后，在显示下一张图像之前，点击后，JPanel颜色会在屏幕上闪烁。在第二次重复相同的技巧期间不会发生这种情况。图像可能需要很长时间才能加载。
是否有一种简单的方法来预加载图像，以便第一次没有延迟？
NOTE: Original code deleted.
EDIT 1/10/2013：此代码现在适用于较慢的计算机。 trashgod的第二个附录帮助最多。 mouseClick控件结构定期要求SwingWorker类加载40个或更少的当前技巧，同时还将使用过的图像设置为null。我已经将我的代码简化为两个Image []并添加了一个main方法，因此它是独立的。仍然需要运行图像。现在这是非常简单的代码，如果你想用大量图片制作幻灯片，我认为这将是一个很好的起点。
注意：我想我在使用多个Image []时想出了如何正确实现SwingWorker。 trashgod和kleopatra这个实现符合你的建议吗？我最终没有使用发布和进程，因为我无法弄清楚如何使用索引数组正常工作，但因为StringWorker没有加载数组中的所有图像（只有40）和代码每隔20个图像调用StringWorker，应该有一个非常好的缓冲区。
EDIT 1/10/2013通过在Mouse类上扩展MouseAdapter来更改MouseListener。还修复了我的paintComponent方法，以包含对super.paintComponent（g）的调用。 向我的SwingWorker类ImageWorker添加了发布/处理方法。添加了一个包装类ArrayWrapper，允许传递imageArray [i]及其相应的索引int i，并使用publish进行处理。
package slideshow3;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import java.util.List;
public class SlideShow3 extends JFrame
{
//screenImage will be replaced with each new slide
private Image screenImage;
private int width;
private int height;
//Create panel for displaying images using paintComponent()
private SlideShow3.PaintPanel mainImagePanel;
//Used for keybinding
private Action escapeAction;
//Image array variables for each trick
private Image[] handCuffs; //h
private Image[] cups; //c
//Used to step through the trick arrays one image at a time
private int h = 0;
private int c = 0;
//Used by timeStamp() for documenting time per slide
private long time0 = 0;
private long time1;
public SlideShow3()
{
super();
//Create instance of each Image array
handCuffs = new Image[50];
cups = new Image[176];
//start(handCuffsString);
start("handCuffs");
try
{
screenImage = ImageIO.read(new File("images/begin1.jpg"));
}
catch (IOException nm)
{
System.out.println("begin");
System.out.println(nm.getMessage());
System.exit(0);
}
/******************************************
* Removes window framing. The next line sets fullscreen mode.
* Once fullscreen is set width and height are determined for the window
******************************************/
this.setUndecorated(true);
GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().setFullScreenWindow(this);
width = this.getWidth();
height = this.getHeight();
//Mouse click binding to slide advance control structure
addMouseListener(new Mouse());
//Create panel so that I can use key binding which requires JComponent
mainImagePanel = new PaintPanel();
add(mainImagePanel);
/******************************************
* Key Binding
* ESC will exit the slideshow
******************************************/
// Key bound AbstractAction items
escapeAction = new EscapeAction();
// Gets the mainImagePanel InputMap and pairs the key to the action
mainImagePanel.getInputMap().put(KeyStroke.getKeyStroke("ESCAPE"), "doEscapeAction");
// This line pairs the AbstractAction enterAction to the action "doEnterAction"
mainImagePanel.getActionMap().put("doEscapeAction", escapeAction);
/******************************************
* End Key Binding
******************************************/
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run()
{
SlideShow3 show = new SlideShow3();
show.setVisible(true);
}
});
}
//This method executes a specific SwingWorker class to preload images
public void start(String e)
{
if(e.equals("handCuffs"))
{
new ImageWorker(handCuffs.length, h, e).execute();
}
else if(e.equals("cups"))
{
new ImageWorker(cups.length, c, e).execute();
}
}
//Stretches and displays images in fullscreen window
private class PaintPanel extends JPanel
{
@Override
public void paintComponent(Graphics g)
{
if(screenImage != null)
{
super.paintComponent(g);
g.drawImage(screenImage, 0, 0, width, height, this);
}
}
}
/******************************************
* The following SwingWorker class Pre-loads all necessary images.
******************************************/
private class ArrayWrapper
{
private int i;
private Image image;
public ArrayWrapper(Image image, int i)
{
this.i = i;
this.image = image;
}
public int getIndex()
{
return i;
}
public Image getImage()
{
return image;
}
}
private class ImageWorker extends SwingWorker<Image[], ArrayWrapper>
{
private int currentPosition;
private int arraySize;
private String trickName;
private Image[] imageArray;
public ImageWorker(int arraySize, int currentPosition, String trick)
{
super();
this.currentPosition = currentPosition;
this.arraySize = arraySize;
this.trickName = trick;
}
@Override
public Image[] doInBackground()
{
imageArray = new Image[arraySize];
for(int i = currentPosition; i < currentPosition+40 && i < arraySize; i++)
{
try
{
imageArray[i] = ImageIO.read(new File("images/" + trickName + (i+1) + ".jpg"));
ArrayWrapper wrapArray = new ArrayWrapper(imageArray[i], i);
publish(wrapArray);
}
catch (IOException e)
{
System.out.println(trickName);
System.out.println(e.getMessage());
System.exit(0);
}
}
return imageArray;
}
@Override
public void process(List<ArrayWrapper> chunks)
{
for(ArrayWrapper element: chunks)
{
if(trickName.equals("handCuffs"))
{
handCuffs[element.getIndex()] = element.getImage();
}
else if(trickName.equals("cups"))
{
cups[element.getIndex()] = element.getImage();
}
}
}
@Override
public void done()
{
try
{
if(trickName.equals("handCuffs"))
{
handCuffs = get();
}
else if(trickName.equals("cups"))
{
cups = get();
}
}
catch(InterruptedException ignore){}
catch(java.util.concurrent.ExecutionException e)
{
String why = null;
Throwable cause = e.getCause();
if(cause != null)
{
why = cause.getMessage();
}
else
{
why = e.getMessage();
}
System.err.println("Error retrieving file: " + why);
}
}
}
/******************************************
* End SwingWorker Pre-Loading Classes
******************************************/
//Prints out time spent on each slide
public void timeStamp()
{
time1 = System.currentTimeMillis();
if(time0 != 0)
{
System.out.println(time1 - time0);
}
time0 = System.currentTimeMillis();
}
/******************************************
* User Input Classes for Key Binding Actions and Mouse Click Actions
******************************************/
private class EscapeAction extends AbstractAction
{
@Override
public void actionPerformed(ActionEvent e)
{
System.exit(0);
}
}
public class Mouse extends MouseAdapter
{
@Override
public void mouseClicked(MouseEvent e)
{
if(!(h<handCuffs.length) && !(c<cups.length))
{
timeStamp();
System.exit(0);
}
else if(h<handCuffs.length)
{
timeStamp();
screenImage = handCuffs[h];
repaint();
System.out.print("handCuffs[" + (h+1) + "]\t");
h++;
//purge used slides and refresh slide buffer
if(h == 20 || h == 40)
{
for(int i = 0; i < h; i++)
{
handCuffs[i] = null;
}
start("handCuffs");
}
if(h == 45)
{
start("cups");
}
}
else if(c<cups.length)
{
timeStamp();
screenImage = cups[c];
repaint();
System.out.print("cups[" + (c+1) + "]\t");
c++;
//purge used slides and refresh slide buffer
if(c == 20 || c == 40 || c == 60 || c == 80 || c == 100 || c == 120 || c == 140 || c == 160)
{
for(int i = 0; i < c; i++)
{
cups[i] = null;
}
start("cups");
}
}
}
}
/******************************************
* End User Input Classes for Key Binding Actions and Mouse Click Actions
******************************************/
}
答案 0 :(得分：5)
此example使用List<ImageIcon>作为cache返回的getImage()图片。使用getResource()，延迟是难以察觉的。默认情况下，下一个和上一个按钮绑定到 Space 键。
附录：您可以使用setEnabled()的{{3}}实例调整按钮的javax.swing.Timer状态来控制导航。
附录：您的第二个示例等待，直到单击鼠标开始读取图像，这是一个可能立即返回副本的不确定进程，或 之后 { {1}}。相反，请使用repaint()开始在后台阅读图片，如图example所示。您可以ImageIO.read() process()显示进度，如here所示。 List<Image>可以从here启动，在您随后在EDT上构建GUI时运行。您可以在处理后立即显示第一张图像。