Java循環播放圖片問題

       昨日在論壇中看到一貼，用Java實現循環播放截圖，遇到問題頗多，下面是他的描述：

    “播放連續截圖的時候都是卡的我眼淚直流，而且JFrame窗體老變白，我在畫圖片之前又將背景繪製成全黑，還是一樣，還有會出現白背景！另外就是，我在將播放的幀數設置爲每秒20幀的時候(也就是每50ms畫一幀)，根本就看不到圖片出現；將其改爲150ms的時候，也能看到圖片的模糊影像，設置爲兩百的時候，纔會出現上上面說的那種很卡的播放效果”

    卡是情有可原，可能JVM內存不足造成，這個可以通過加大JVM內存來解決；而窗體發白，背景發黑這種情況我倒是沒遇見過，前段時間做過一個切圖工具，圖片超大時（17MB，遊戲地圖）是很卡，不夠也能順利切割；圖片循環播放也是一個挺簡單的問題，怎麼會出現這樣情況呢，會不會是界面重繪出了問題，動手試一試：

    下面是一個用於循環播放圖片的DisplayJPanel，繼承了類JPanel和接口Runnable，把這個DisplayJPanel放在上層容器如JScrollPane上傳入參數即可，很簡單的一段代碼：

 

import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.ArrayList; import java.util.List; import javax.swing.JPanel; /** * * 循環播放圖片 * * @author monitor * Created on 2010-12-22, 16:38:02 */ public class DisplayJPanel extends JPanel implements Runnable{ /** 背景顏色 */ private final Color B_COLOR=Color.LIGHT_GRAY; /** 起始X座標 */ private final int WORK_X=10; /** 起始Y座標 */ private final int WORK_Y=10; /** 要播放的圖片 */ private List<BufferedImage> imageList=new ArrayList<BufferedImage>(); /** 當前要畫的圖片 */ private BufferedImage currentImage=null; /** 播放延時 */ private int delay=50; /** 是否播放 */ private boolean work=true; /** 是否暫停 */ private boolean stop=false; /** * 構造一個最初沒有圖片顯示的DisplayJPanel對象 */ public DisplayJPanel(){ } /** * 構造一個帶有要播放圖片列表的DisplayJPanel對象 * @param imageList 要播放的圖片列表 */ public DisplayJPanel(List<BufferedImage> imageList){ this.imageList=imageList; } /** * 循環播放圖片列表 */ public void run(){ while(work){ if(stop || imageList==null || imageList.isEmpty()){ sleep(1000); continue; } for(BufferedImage image:imageList){ currentImage=image; repaint(); sleep(delay); } } } @Override public void paintComponent(Graphics g){ g.setColor(B_COLOR); g.fillRect(0, 0,this.getWidth(),this.getHeight()); if(currentImage!=null){ g.drawImage(currentImage,WORK_X,WORK_Y,null); } } /** * 線程睡眠 * @param s 睡眠時間（ms） */ private void sleep(int s){ try{ Thread.sleep(s); }catch(Exception e){ } } /** * 設置播放幀延時 * @param delay 幀延時（ms） */ public void setDelay(int delay) { this.delay = delay; } /** * 設置要播放的圖片列表 * @param imageList 要播放的圖片列表 */ public void setImageList(List<BufferedImage> imageList) { this.imageList = imageList; } /** * 設置是否播放 * @param work ture 播放，false 不播放 */ public void setWork(boolean work) { this.work = work; } /** * 設置是否暫停 * @param stop ture 暫停，false 不暫停 */ public void setStop(boolean stop) { this.stop = stop; } }

    用Netbeans做了很簡單的邊框佈局的界面，界面效果如下：

    代碼如下：

 package com.monitor.imagetest; import java.awt.Dimension; import java.awt.Toolkit; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.logging.Level; import java.util.logging.Logger; import javax.imageio.ImageIO; import javax.swing.DefaultListModel; import javax.swing.JFileChooser; import javax.swing.JOptionPane; /* * MainUI.java * * 圖片循環播放 * * @author monitor * Created on 2010-12-22, 16:49:47 */ public class MainUI extends javax.swing.JFrame { private DisplayJPanel display=null; private DefaultListModel imageModel=new DefaultListModel(); private List<BufferedImage> imageList=new ArrayList<BufferedImage>(); /** * 構造一個MainUI對象 */ public MainUI() { initComponents(); init(); } /** * 界面初始化 */ private void init(){ //居中顯示 Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int screenWidth=(int)screenSize.getWidth(); int screenHeight=(int)screenSize.getHeight(); int width=this.getWidth(); int height=this.getHeight(); this.setBounds((screenWidth-width)/2,(screenHeight-height)/2,width ,height); display=new DisplayJPanel(); imagePane.setViewportView(display); new Thread(display).start(); //進度圖不可視 bar.setVisible(false); } @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents private void initComponents() { jPanel1 = new javax.swing.JPanel(); jLabel1 = new javax.swing.JLabel(); jPanel2 = new javax.swing.JPanel(); msgLabel = new javax.swing.JLabel(); bar = new javax.swing.JProgressBar(); jPanel3 = new javax.swing.JPanel(); jPanel4 = new javax.swing.JPanel(); jLabel2 = new javax.swing.JLabel(); delaySpin = new javax.swing.JSpinner(); jToolBar1 = new javax.swing.JToolBar(); importButton = new javax.swing.JButton(); playButton = new javax.swing.JButton(); stopButton = new javax.swing.JButton(); goonButton = new javax.swing.JButton(); imagePane = new javax.swing.JScrollPane(); jScrollPane1 = new javax.swing.JScrollPane(); imageJList = new javax.swing.JList(); jMenuBar1 = new javax.swing.JMenuBar(); jMenu1 = new javax.swing.JMenu(); jMenu2 = new javax.swing.JMenu(); jMenu3 = new javax.swing.JMenu(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); jLabel1.setFont(new java.awt.Font("宋體", 0, 36)); jLabel1.setText("圖片播放"); jPanel1.add(jLabel1); getContentPane().add(jPanel1, java.awt.BorderLayout.PAGE_START); jPanel2.setBorder(javax.swing.BorderFactory.createEtchedBorder()); jPanel2.setLayout(new java.awt.GridLayout(1, 0)); jPanel2.add(msgLabel); jPanel2.add(bar); getContentPane().add(jPanel2, java.awt.BorderLayout.PAGE_END); jPanel3.setBorder(javax.swing.BorderFactory.createEmptyBorder(1, 1, 1, 1)); jPanel4.setBorder(javax.swing.BorderFactory.createEtchedBorder()); jLabel2.setText("播放延時(ms)："); delaySpin.setModel(new javax.swing.SpinnerNumberModel(Integer.valueOf(50), Integer.valueOf(10), null, Integer.valueOf(1))); delaySpin.addChangeListener(new javax.swing.event.ChangeListener() { public void stateChanged(javax.swing.event.ChangeEvent evt) { delaySpinStateChanged(evt); } }); jToolBar1.setRollover(true); importButton.setText("導入"); importButton.setFocusable(false); importButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); importButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); importButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { importButtonActionPerformed(evt); } }); jToolBar1.add(importButton); playButton.setText("播放"); playButton.setFocusable(false); playButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); playButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); playButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { playButtonActionPerformed(evt); } }); jToolBar1.add(playButton); stopButton.setText("暫停"); stopButton.setFocusable(false); stopButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); stopButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); stopButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { stopButtonActionPerformed(evt); } }); jToolBar1.add(stopButton); goonButton.setText("繼續"); goonButton.setFocusable(false); goonButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER); goonButton.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM); goonButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { goonButtonActionPerformed(evt); } }); jToolBar1.add(goonButton); javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4); jPanel4.setLayout(jPanel4Layout); jPanel4Layout.setHorizontalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel4Layout.createSequentialGroup() .addComponent(jLabel2) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(delaySpin, javax.swing.GroupLayout.PREFERRED_SIZE, 59, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, 531, Short.MAX_VALUE)) ); jPanel4Layout.setVerticalGroup( jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER) .addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(delaySpin, javax.swing.GroupLayout.DEFAULT_SIZE, 23, Short.MAX_VALUE) .addComponent(jLabel2)) ); imageJList.setModel(imageModel); jScrollPane1.setViewportView(imageJList); javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3); jPanel3.setLayout(jPanel3Layout); jPanel3Layout.setHorizontalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel3Layout.createSequentialGroup() .addContainerGap() .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING) .addGroup(jPanel3Layout.createSequentialGroup() .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 150, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(imagePane, javax.swing.GroupLayout.DEFAULT_SIZE, 532, Short.MAX_VALUE)) .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) .addContainerGap()) ); jPanel3Layout.setVerticalGroup( jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel3Layout.createSequentialGroup() .addContainerGap() .addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE) .addComponent(imagePane, javax.swing.GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE)) .addContainerGap()) ); getContentPane().add(jPanel3, java.awt.BorderLayout.CENTER); jMenu1.setText("文件"); jMenuBar1.add(jMenu1); jMenu2.setText("編輯"); jMenuBar1.add(jMenu2); jMenu3.setText("編輯"); jMenuBar1.add(jMenu3); setJMenuBar(jMenuBar1); pack(); }// </editor-fold>//GEN-END:initComponents /** * 用線程導入圖片，並在界面顯示信息 * @param evt 觸發事件 */ private void importButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_importButtonActionPerformed new Thread(new Runnable() { public void run() { JFileChooser fileChooser = new JFileChooser(); fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); int flag=fileChooser.showOpenDialog(null); if(flag!=JFileChooser.APPROVE_OPTION){ return; } File importFile = fileChooser.getSelectedFile(); if (importFile==null) { return; } imageModel.removeAllElements(); int i=1; bar.setVisible(true); bar.setIndeterminate(true); for(File file:importFile.listFiles()){ try { msgLabel.setText("正在導入："+file.getName()); imageList.add(ImageIO.read(file)); imageModel.addElement(file.getName()); i++; } catch (IOException ex) { System.out.println("非圖片文件"); //Logger.getLogger(MainUI.class.getName()).log(Level.SEVERE, null, ex); } } bar.setVisible(false); msgLabel.setText("導入完畢！共"+i+"張圖片，播放圖片請點擊“播放”按鈕"); }}).start(); }//GEN-LAST:event_importButtonActionPerformed /** * 播放 * @param evt */ private void playButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_playButtonActionPerformed if(imageList==null || imageList.isEmpty()){ String msg="請輸入導入要播放的圖片"; JOptionPane.showMessageDialog(this, msg , "提示", JOptionPane.INFORMATION_MESSAGE); return; } display.setImageList(imageList); }//GEN-LAST:event_playButtonActionPerformed /** * 修改幀延時 * @param evt */ private void delaySpinStateChanged(javax.swing.event.ChangeEvent evt) {//GEN-FIRST:event_delaySpinStateChanged int delay=(Integer)delaySpin.getValue(); if(delay>=10){ display.setDelay(delay); } }//GEN-LAST:event_delaySpinStateChanged /** * 暫停 * @param evt */ private void stopButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_stopButtonActionPerformed display.setStop(true); }//GEN-LAST:event_stopButtonActionPerformed /** * 繼續 * @param evt */ private void goonButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_goonButtonActionPerformed display.setStop(false); }//GEN-LAST:event_goonButtonActionPerformed // Variables declaration - do not modify//GEN-BEGIN:variables private javax.swing.JProgressBar bar; private javax.swing.JSpinner delaySpin; private javax.swing.JButton goonButton; private javax.swing.JList imageJList; private javax.swing.JScrollPane imagePane; private javax.swing.JButton importButton; private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JMenu jMenu1; private javax.swing.JMenu jMenu2; private javax.swing.JMenu jMenu3; private javax.swing.JMenuBar jMenuBar1; private javax.swing.JPanel jPanel1; private javax.swing.JPanel jPanel2; private javax.swing.JPanel jPanel3; private javax.swing.JPanel jPanel4; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JToolBar jToolBar1; private javax.swing.JLabel msgLabel; private javax.swing.JButton playButton; private javax.swing.JButton stopButton; // End of variables declaration//GEN-END:variables }

        我也測試了一下，從屏幕截了一張圖，尺寸爲1081*636大小爲139KB的JPG圖片，共複製了424張，總大小57.9MB，給程序分配了900MB內存（不能少於700MB），導入圖片時另開線程導入；播放沒有問題，很流暢，沒有出現界面發白背景發黑的情況。

    一次把圖片都加載到內存這種方案最大的不足就是當圖片很多很大時要耗費大量的內存，容易出現內存溢出錯誤，難於控制。可以改成實時加載的方案，要畫到的圖片才用ImageIO從文件讀取，畫完就釋放，當播放速度不是很快時這完全滿足要求。