绘画 canvas 和 System.out.println() 不工作
Painting canvas and System.out.println() not working
我 JFrame 有一个开始按钮，它会触发 Julia Set 的计算。
单击开始按钮时执行的代码如下：
public void actionPerformed(ActionEvent aActionEvent)
{
String strCmd = aActionEvent.getActionCommand();
if (strCmd.equals("Start"))
{
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
this.handleCalculation();
}
else if (aActionEvent.getSource() == m_cTReal)
以前工作正常，只是应用程序无法再关闭。所以我尝试在单独的方法中使用 m_bRunning，这样 actionPerformed() 就不会一直被阻塞，看看是否有帮助，然后在方法 stop() 中设置 m_bRunning = false ] 当 window 关闭时调用：
public void run()
{
if(m_bRunning)
{
this.handleCalculation();
}
}
方法 run() 在 while(true) 循环中从主 class 调用。
然而不幸的是，这既没有解决问题，我现在也没有任何输出到 canvas 或任何带有 System.out.println() 的调试跟踪。谁能指出我正确的方向？
编辑：
完整文件如下：
// cMain.java
package juliaSet;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.Dimension;
public class cMain {
public static void main(String[] args)
{
int windowWidth = 1000;//(int)screenSize.getWidth() - 200;
int windowHeight = 800;//(int)screenSize.getHeight() - 50;
int plotWidth = 400;//(int)screenSize.getWidth() - 600;
int plotHeight = 400;//(int)screenSize.getHeight() - 150;
JuliaSet cJuliaSet = new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
cJuliaSet.setVisible(true);
while(true)
{
cJuliaSet.run();
}
}
}
// JuliaSet.java
package juliaSet;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.util.Random;
import java.io.*;
import java.lang.ref.*;
public class JuliaSet extends JFrame implements ActionListener
{
private JButton m_cBStart;
private JTextField m_cTReal;
private JTextField m_cTImag;
private JTextField m_cTDivergThresh;
private JLabel m_cLReal;
private JLabel m_cLImag;
private JLabel m_cLDivergThresh;
private int m_iDivergThresh = 10;
private String m_cMsgDivThresh = "Divergence threshold = " + m_iDivergThresh;
private JuliaCanvas m_cCanvas;
private int m_iPlotWidth; // number of cells
private int m_iPlotHeight; // number of cells
private Boolean m_bRunning = false;
private double m_dReal = 0.3;
private double m_dImag = -0.5;
private String m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
private String m_cMsgIter = "x = 0, y = 0";
private Complex m_cCoordPlane[][];
private double m_dAbsSqValues[][];
private int m_iIterations[][];
private Complex m_cSummand;
private BufferedImage m_cBackGroundImage = null;
private FileWriter m_cFileWriter;
private BufferedWriter m_cBufferedWriter;
private String m_sFileName = "log.txt";
private Boolean m_bWriteLog = false;
private static final double PLOTMAX = 2.0; // we'll have symmetric axes
// ((0,0) at the centre of the
// plot
private static final int MAXITER = 0xff;
JuliaSet(String aTitle, int aFrameWidth, int aFrameHeight, int aPlotWidth, int aPlotHeight)
{
super(aTitle);
this.setSize(aFrameWidth, aFrameHeight);
m_iPlotWidth = aPlotWidth;
m_iPlotHeight = aPlotHeight;
m_cSummand = new Complex(m_dReal, m_dImag);
m_cBackGroundImage = new BufferedImage(aFrameWidth, aFrameHeight, BufferedImage.TYPE_INT_RGB);
this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
stop();
super.windowClosing(e);
System.exit(0);
}
});
GridBagLayout cLayout = new GridBagLayout();
GridBagConstraints cConstraints = new GridBagConstraints();
this.setLayout(cLayout);
m_cCanvas = new JuliaCanvas(m_iPlotWidth, m_iPlotHeight);
m_cCanvas.setSize(m_iPlotWidth, m_iPlotHeight);
m_cBStart = new JButton("Start");
m_cBStart.addActionListener(this);
m_cTReal = new JTextField(5);
m_cTReal.addActionListener(this);
m_cTImag = new JTextField(5);
m_cTImag.addActionListener(this);
m_cTDivergThresh = new JTextField(5);
m_cTDivergThresh.addActionListener(this);
m_cLReal = new JLabel("Re(c):");
m_cLImag = new JLabel("Im(c):");
m_cLDivergThresh = new JLabel("Divergence Threshold:");
cConstraints.insets.top = 3;
cConstraints.insets.bottom = 3;
cConstraints.insets.right = 3;
cConstraints.insets.left = 3;
// cCanvas
cConstraints.gridx = 0;
cConstraints.gridy = 0;
cLayout.setConstraints(m_cCanvas, cConstraints);
this.add(m_cCanvas);
// m_cLReal
cConstraints.gridx = 0;
cConstraints.gridy = 1;
cLayout.setConstraints(m_cLReal, cConstraints);
this.add(m_cLReal);
// m_cTReal
cConstraints.gridx = 1;
cConstraints.gridy = 1;
cLayout.setConstraints(m_cTReal, cConstraints);
this.add(m_cTReal);
// m_cLImag
cConstraints.gridx = 0;
cConstraints.gridy = 2;
cLayout.setConstraints(m_cLImag, cConstraints);
this.add(m_cLImag);
// m_cTImag
cConstraints.gridx = 1;
cConstraints.gridy = 2;
cLayout.setConstraints(m_cTImag, cConstraints);
this.add(m_cTImag);
// m_cLDivergThresh
cConstraints.gridx = 0;
cConstraints.gridy = 3;
cLayout.setConstraints(m_cLDivergThresh, cConstraints);
this.add(m_cLDivergThresh);
// m_cTDivergThresh
cConstraints.gridx = 1;
cConstraints.gridy = 3;
cLayout.setConstraints(m_cTDivergThresh, cConstraints);
this.add(m_cTDivergThresh);
// m_cBStart
cConstraints.gridx = 0;
cConstraints.gridy = 4;
cLayout.setConstraints(m_cBStart, cConstraints);
this.add(m_cBStart);
if (m_bWriteLog)
{
try
{
m_cFileWriter = new FileWriter(m_sFileName, false);
m_cBufferedWriter = new BufferedWriter(m_cFileWriter);
} catch (IOException ex) {
System.out.println("Error opening file '" + m_sFileName + "'");
}
}
this.repaint();
this.transformCoordinates();
}
public synchronized void stop()
{
if (m_bRunning)
{
m_bRunning = false;
boolean bRetry = true;
}
if (m_bWriteLog)
{
try {
m_cBufferedWriter.close();
m_cFileWriter.close();
} catch (IOException ex) {
System.out.println("Error closing file '" + m_sFileName + "'");
}
}
}
public void collectGarbage()
{
Object cObj = new Object();
WeakReference ref = new WeakReference<Object>(cObj);
cObj = null;
while(ref.get() != null) {
System.gc();
}
}
public void setSummand(Complex aSummand)
{
m_cSummand.setIm(aSummand.getIm());
m_dImag = aSummand.getIm();
m_cSummand.setRe(aSummand.getRe());
m_dReal = aSummand.getRe();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
}
public void paint(Graphics aGraphics)
{
Graphics cScreenGraphics = aGraphics;
// render on background image
aGraphics = m_cBackGroundImage.getGraphics();
this.paintComponents(aGraphics);
// drawString() calls are debug code only....
aGraphics.setColor(Color.BLACK);
aGraphics.drawString(m_cSMsg, 10, 450);
aGraphics.drawString(m_cMsgIter, 10, 465);
aGraphics.drawString(m_cMsgDivThresh, 10, 480);
// rendering is done, draw background image to on screen graphics
cScreenGraphics.drawImage(m_cBackGroundImage, 0, 0, null);
}
public void actionPerformed(ActionEvent aActionEvent)
{
String strCmd = aActionEvent.getActionCommand();
if (strCmd.equals("Start"))
{
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
}
else if (aActionEvent.getSource() == m_cTReal)
{
m_dReal = Double.parseDouble(m_cTReal.getText());
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_cSummand.setRe(m_dReal);
}
else if (aActionEvent.getSource() == m_cTImag)
{
m_dImag = Double.parseDouble(m_cTImag.getText());
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_cSummand.setIm(m_dImag);
}
else if (aActionEvent.getSource() == m_cTDivergThresh)
{
m_iDivergThresh = Integer.parseInt(m_cTDivergThresh.getText());
m_cMsgDivThresh = "Divergence threshold = " + m_iDivergThresh;
}
this.update(this.getGraphics());
}
public void transformCoordinates()
{
double dCanvasHeight = (double) m_cCanvas.getHeight();
double dCanvasWidth = (double) m_cCanvas.getWidth();
// init matrix with same amount of elements as pixels in canvas
m_cCoordPlane = new Complex[(int) dCanvasHeight][(int) dCanvasWidth];
double iPlotRange = 2 * PLOTMAX;
for (int i = 0; i < dCanvasHeight; i++)
{
for (int j = 0; j < dCanvasWidth; j++)
{
m_cCoordPlane[i][j] = new Complex((i - (dCanvasWidth / 2)) * iPlotRange / dCanvasWidth,
(j - (dCanvasHeight / 2)) * iPlotRange / dCanvasHeight);
}
}
}
public void calcAbsSqValues()
{
int iCanvasHeight = m_cCanvas.getHeight();
int iCanvasWidth = m_cCanvas.getWidth();
// init matrix with same amount of elements as pixels in canvas
m_dAbsSqValues = new double[iCanvasHeight][iCanvasWidth];
m_iIterations = new int[iCanvasHeight][iCanvasWidth];
Complex cSum = new Complex();
if (m_bWriteLog) {
try
{
m_cBufferedWriter.write("m_iIterations[][] =");
m_cBufferedWriter.newLine();
}
catch (IOException ex)
{
System.out.println("Error opening file '" + m_sFileName + "'");
}
}
for (int i = 0; i < iCanvasHeight; i++)
{
for (int j = 0; j < iCanvasWidth; j++)
{
cSum.setRe(m_cCoordPlane[i][j].getRe());
cSum.setIm(m_cCoordPlane[i][j].getIm());
m_iIterations[i][j] = 0;
do
{
m_iIterations[i][j]++;
cSum.square();
cSum.add(m_cSummand);
m_dAbsSqValues[i][j] = cSum.getAbsSq();
} while ((m_iIterations[i][j] < MAXITER) && (m_dAbsSqValues[i][j] < m_iDivergThresh));
this.calcColour(i, j, m_iIterations[i][j]);
m_cMsgIter = "x = " + i + " , y = " + j;
if(m_bWriteLog)
{
System.out.println(m_cMsgIter);
System.out.flush();
}
if (m_bWriteLog) {
try
{
m_cBufferedWriter.write(Integer.toString(m_iIterations[i][j]));
m_cBufferedWriter.write(" ");
}
catch (IOException ex) {
System.out.println("Error writing to file '" + m_sFileName + "'");
}
}
}
if (m_bWriteLog) {
try
{
m_cBufferedWriter.newLine();
}
catch (IOException ex) {
System.out.println("Error writing to file '" + m_sFileName + "'");
}
}
}
m_dAbsSqValues = null;
m_iIterations = null;
cSum = null;
}
private void calcColour(int i, int j, int aIterations)
{
Color cColour = Color.getHSBColor((int) Math.pow(aIterations, 4), 0xff,
0xff * ((aIterations < MAXITER) ? 1 : 0));
m_cCanvas.setPixelColour(i, j, cColour);
cColour = null;
}
private void handleCalculation()
{
Complex cSummand = new Complex();
for(int i = -800; i <= 800; i++)
{
for(int j = -800; j <= 800; j++)
{
cSummand.setRe(((double)i)/1000.0);
cSummand.setIm(((double)j)/1000.0);
this.setSummand(cSummand);
this.calcAbsSqValues();
this.getCanvas().paint(m_cCanvas.getGraphics());
this.paint(this.getGraphics());
}
}
cSummand = null;
this.collectGarbage();
System.gc();
System.runFinalization();
}
public boolean isRunning()
{
return m_bRunning;
}
public void setRunning(boolean aRunning)
{
m_bRunning = aRunning;
}
public Canvas getCanvas()
{
return m_cCanvas;
}
public void run()
{
if(m_bRunning)
{
this.handleCalculation();
}
}
}
class JuliaCanvas extends Canvas
{
private int m_iWidth;
private int m_iHeight;
private Random m_cRnd;
private BufferedImage m_cBackGroundImage = null;
private int m_iRed[][];
private int m_iGreen[][];
private int m_iBlue[][];
JuliaCanvas(int aWidth, int aHeight)
{
m_iWidth = aWidth;
m_iHeight = aHeight;
m_cRnd = new Random();
m_cRnd.setSeed(m_cRnd.nextLong());
m_cBackGroundImage = new BufferedImage(m_iWidth, m_iHeight, BufferedImage.TYPE_INT_RGB);
m_iRed = new int[m_iHeight][m_iWidth];
m_iGreen = new int[m_iHeight][m_iWidth];
m_iBlue = new int[m_iHeight][m_iWidth];
}
public void init() {
}
public void setPixelColour(int i, int j, Color aColour)
{
m_iRed[i][j] = aColour.getRed();
m_iGreen[i][j] = aColour.getGreen();
m_iBlue[i][j] = aColour.getBlue();
}
private int getRandomInt(double aProbability)
{
return (m_cRnd.nextDouble() < aProbability) ? 1 : 0;
}
@Override
public void paint(Graphics aGraphics)
{
// store on screen graphics
Graphics cScreenGraphics = aGraphics;
// render on background image
aGraphics = m_cBackGroundImage.getGraphics();
for (int i = 0; i < m_iWidth; i++)
{
for (int j = 0; j < m_iHeight; j++)
{
Color cColor = new Color(m_iRed[i][j], m_iGreen[i][j], m_iBlue[i][j]);
aGraphics.setColor(cColor);
aGraphics.drawRect(i, j, 0, 0);
cColor = null;
}
}
// rendering is done, draw background image to on screen graphics
cScreenGraphics.drawImage(m_cBackGroundImage, 1, 1, null);
}
@Override
public void update(Graphics aGraphics)
{
paint(aGraphics);
}
}
class Complex {
private double m_dRe;
private double m_dIm;
public Complex()
{
m_dRe = 0;
m_dIm = 0;
}
public Complex(double aRe, double aIm)
{
m_dRe = aRe;
m_dIm = aIm;
}
public Complex(Complex aComplex)
{
m_dRe = aComplex.m_dRe;
m_dIm = aComplex.m_dIm;
}
public double getRe() {
return m_dRe;
}
public void setRe(double adRe)
{
m_dRe = adRe;
}
public double getIm() {
return m_dIm;
}
public void setIm(double adIm)
{
m_dIm = adIm;
}
public void add(Complex acComplex)
{
m_dRe += acComplex.getRe();
m_dIm += acComplex.getIm();
}
public void square()
{
double m_dReSave = m_dRe;
m_dRe = (m_dRe * m_dRe) - (m_dIm * m_dIm);
m_dIm = 2 * m_dReSave * m_dIm;
}
public double getAbsSq()
{
return ((m_dRe * m_dRe) + (m_dIm * m_dIm));
}
}
第一个；
无限循环不是执行此操作的正确方法。这部分是循环并使用 CPU 并且从不给 canvas 来刷新屏幕。如果您添加以下代码，您的代码将按预期 运行。但这不是正确的解决方案。
cMain.java:
while (true) {
cJuliaSet.run();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
其次：您可以在单击开始按钮时调用 运行 方法。但是你应该在 运行 方法中创建一个线程来不冻结屏幕。
public static void main(String[] args) {
int windowWidth = 1000;// (int)screenSize.getWidth() - 200;
int windowHeight = 800;// (int)screenSize.getHeight() - 50;
int plotWidth = 400;// (int)screenSize.getWidth() - 600;
int plotHeight = 400;// (int)screenSize.getHeight() - 150;
JuliaSet cJuliaSet = new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
cJuliaSet.setVisible(true);
//While loop removed
}
执行的动作：
if (strCmd.equals("Start")) {
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
this.run(); // added call run method.
} else if (aActionEvent.getSource() == m_cTReal) {
运行方法：
public void run()
{
if(m_bRunning)
{
new Thread(){ //Thread to release screen
@Override
public void run() {
JuliaSet.this.handleCalculation();
}
}.start(); //also thread must be started
}
}
正如@RubioRic 所说，SwingUtilities.invokeLater 方法也是解决方案的一部分。但是您需要检查整个代码并且您应该了解线程。
我引用@MadProgrammer 最近的评论（包括链接）
"Swing is single threaded, nothing you can do to change that, all events are posted to the event queue and processed by the Event Dispatching Thread, see Concurrency in Swing for more details and have a look at Worker Threads and SwingWorker for at least one possible solution"
您的代码中只有一个线程。该线程正忙于计算，无法响应 GUI 中的事件。您必须在另一个线程中分离计算，该线程定期更新 window 中出现的数量。我坚持在链接中提供有关此内容的更多信息，由@MadProgrammer 提供。
更新：正如@Yusuf 所指出的，启动 JFrame 的正确方法是
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
}
});
设置框架在构建时可见，并在按下开始按钮时开始计算。
我 JFrame 有一个开始按钮，它会触发 Julia Set 的计算。
单击开始按钮时执行的代码如下：
public void actionPerformed(ActionEvent aActionEvent)
{
String strCmd = aActionEvent.getActionCommand();
if (strCmd.equals("Start"))
{
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
this.handleCalculation();
}
else if (aActionEvent.getSource() == m_cTReal)
以前工作正常，只是应用程序无法再关闭。所以我尝试在单独的方法中使用 m_bRunning，这样 actionPerformed() 就不会一直被阻塞，看看是否有帮助，然后在方法 stop() 中设置 m_bRunning = false ] 当 window 关闭时调用：
public void run()
{
if(m_bRunning)
{
this.handleCalculation();
}
}
方法 run() 在 while(true) 循环中从主 class 调用。
然而不幸的是，这既没有解决问题，我现在也没有任何输出到 canvas 或任何带有 System.out.println() 的调试跟踪。谁能指出我正确的方向？
编辑：
完整文件如下：
// cMain.java
package juliaSet;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.Dimension;
public class cMain {
public static void main(String[] args)
{
int windowWidth = 1000;//(int)screenSize.getWidth() - 200;
int windowHeight = 800;//(int)screenSize.getHeight() - 50;
int plotWidth = 400;//(int)screenSize.getWidth() - 600;
int plotHeight = 400;//(int)screenSize.getHeight() - 150;
JuliaSet cJuliaSet = new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
cJuliaSet.setVisible(true);
while(true)
{
cJuliaSet.run();
}
}
}
// JuliaSet.java
package juliaSet;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.util.Random;
import java.io.*;
import java.lang.ref.*;
public class JuliaSet extends JFrame implements ActionListener
{
private JButton m_cBStart;
private JTextField m_cTReal;
private JTextField m_cTImag;
private JTextField m_cTDivergThresh;
private JLabel m_cLReal;
private JLabel m_cLImag;
private JLabel m_cLDivergThresh;
private int m_iDivergThresh = 10;
private String m_cMsgDivThresh = "Divergence threshold = " + m_iDivergThresh;
private JuliaCanvas m_cCanvas;
private int m_iPlotWidth; // number of cells
private int m_iPlotHeight; // number of cells
private Boolean m_bRunning = false;
private double m_dReal = 0.3;
private double m_dImag = -0.5;
private String m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
private String m_cMsgIter = "x = 0, y = 0";
private Complex m_cCoordPlane[][];
private double m_dAbsSqValues[][];
private int m_iIterations[][];
private Complex m_cSummand;
private BufferedImage m_cBackGroundImage = null;
private FileWriter m_cFileWriter;
private BufferedWriter m_cBufferedWriter;
private String m_sFileName = "log.txt";
private Boolean m_bWriteLog = false;
private static final double PLOTMAX = 2.0; // we'll have symmetric axes
// ((0,0) at the centre of the
// plot
private static final int MAXITER = 0xff;
JuliaSet(String aTitle, int aFrameWidth, int aFrameHeight, int aPlotWidth, int aPlotHeight)
{
super(aTitle);
this.setSize(aFrameWidth, aFrameHeight);
m_iPlotWidth = aPlotWidth;
m_iPlotHeight = aPlotHeight;
m_cSummand = new Complex(m_dReal, m_dImag);
m_cBackGroundImage = new BufferedImage(aFrameWidth, aFrameHeight, BufferedImage.TYPE_INT_RGB);
this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
stop();
super.windowClosing(e);
System.exit(0);
}
});
GridBagLayout cLayout = new GridBagLayout();
GridBagConstraints cConstraints = new GridBagConstraints();
this.setLayout(cLayout);
m_cCanvas = new JuliaCanvas(m_iPlotWidth, m_iPlotHeight);
m_cCanvas.setSize(m_iPlotWidth, m_iPlotHeight);
m_cBStart = new JButton("Start");
m_cBStart.addActionListener(this);
m_cTReal = new JTextField(5);
m_cTReal.addActionListener(this);
m_cTImag = new JTextField(5);
m_cTImag.addActionListener(this);
m_cTDivergThresh = new JTextField(5);
m_cTDivergThresh.addActionListener(this);
m_cLReal = new JLabel("Re(c):");
m_cLImag = new JLabel("Im(c):");
m_cLDivergThresh = new JLabel("Divergence Threshold:");
cConstraints.insets.top = 3;
cConstraints.insets.bottom = 3;
cConstraints.insets.right = 3;
cConstraints.insets.left = 3;
// cCanvas
cConstraints.gridx = 0;
cConstraints.gridy = 0;
cLayout.setConstraints(m_cCanvas, cConstraints);
this.add(m_cCanvas);
// m_cLReal
cConstraints.gridx = 0;
cConstraints.gridy = 1;
cLayout.setConstraints(m_cLReal, cConstraints);
this.add(m_cLReal);
// m_cTReal
cConstraints.gridx = 1;
cConstraints.gridy = 1;
cLayout.setConstraints(m_cTReal, cConstraints);
this.add(m_cTReal);
// m_cLImag
cConstraints.gridx = 0;
cConstraints.gridy = 2;
cLayout.setConstraints(m_cLImag, cConstraints);
this.add(m_cLImag);
// m_cTImag
cConstraints.gridx = 1;
cConstraints.gridy = 2;
cLayout.setConstraints(m_cTImag, cConstraints);
this.add(m_cTImag);
// m_cLDivergThresh
cConstraints.gridx = 0;
cConstraints.gridy = 3;
cLayout.setConstraints(m_cLDivergThresh, cConstraints);
this.add(m_cLDivergThresh);
// m_cTDivergThresh
cConstraints.gridx = 1;
cConstraints.gridy = 3;
cLayout.setConstraints(m_cTDivergThresh, cConstraints);
this.add(m_cTDivergThresh);
// m_cBStart
cConstraints.gridx = 0;
cConstraints.gridy = 4;
cLayout.setConstraints(m_cBStart, cConstraints);
this.add(m_cBStart);
if (m_bWriteLog)
{
try
{
m_cFileWriter = new FileWriter(m_sFileName, false);
m_cBufferedWriter = new BufferedWriter(m_cFileWriter);
} catch (IOException ex) {
System.out.println("Error opening file '" + m_sFileName + "'");
}
}
this.repaint();
this.transformCoordinates();
}
public synchronized void stop()
{
if (m_bRunning)
{
m_bRunning = false;
boolean bRetry = true;
}
if (m_bWriteLog)
{
try {
m_cBufferedWriter.close();
m_cFileWriter.close();
} catch (IOException ex) {
System.out.println("Error closing file '" + m_sFileName + "'");
}
}
}
public void collectGarbage()
{
Object cObj = new Object();
WeakReference ref = new WeakReference<Object>(cObj);
cObj = null;
while(ref.get() != null) {
System.gc();
}
}
public void setSummand(Complex aSummand)
{
m_cSummand.setIm(aSummand.getIm());
m_dImag = aSummand.getIm();
m_cSummand.setRe(aSummand.getRe());
m_dReal = aSummand.getRe();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
}
public void paint(Graphics aGraphics)
{
Graphics cScreenGraphics = aGraphics;
// render on background image
aGraphics = m_cBackGroundImage.getGraphics();
this.paintComponents(aGraphics);
// drawString() calls are debug code only....
aGraphics.setColor(Color.BLACK);
aGraphics.drawString(m_cSMsg, 10, 450);
aGraphics.drawString(m_cMsgIter, 10, 465);
aGraphics.drawString(m_cMsgDivThresh, 10, 480);
// rendering is done, draw background image to on screen graphics
cScreenGraphics.drawImage(m_cBackGroundImage, 0, 0, null);
}
public void actionPerformed(ActionEvent aActionEvent)
{
String strCmd = aActionEvent.getActionCommand();
if (strCmd.equals("Start"))
{
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
}
else if (aActionEvent.getSource() == m_cTReal)
{
m_dReal = Double.parseDouble(m_cTReal.getText());
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_cSummand.setRe(m_dReal);
}
else if (aActionEvent.getSource() == m_cTImag)
{
m_dImag = Double.parseDouble(m_cTImag.getText());
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_cSummand.setIm(m_dImag);
}
else if (aActionEvent.getSource() == m_cTDivergThresh)
{
m_iDivergThresh = Integer.parseInt(m_cTDivergThresh.getText());
m_cMsgDivThresh = "Divergence threshold = " + m_iDivergThresh;
}
this.update(this.getGraphics());
}
public void transformCoordinates()
{
double dCanvasHeight = (double) m_cCanvas.getHeight();
double dCanvasWidth = (double) m_cCanvas.getWidth();
// init matrix with same amount of elements as pixels in canvas
m_cCoordPlane = new Complex[(int) dCanvasHeight][(int) dCanvasWidth];
double iPlotRange = 2 * PLOTMAX;
for (int i = 0; i < dCanvasHeight; i++)
{
for (int j = 0; j < dCanvasWidth; j++)
{
m_cCoordPlane[i][j] = new Complex((i - (dCanvasWidth / 2)) * iPlotRange / dCanvasWidth,
(j - (dCanvasHeight / 2)) * iPlotRange / dCanvasHeight);
}
}
}
public void calcAbsSqValues()
{
int iCanvasHeight = m_cCanvas.getHeight();
int iCanvasWidth = m_cCanvas.getWidth();
// init matrix with same amount of elements as pixels in canvas
m_dAbsSqValues = new double[iCanvasHeight][iCanvasWidth];
m_iIterations = new int[iCanvasHeight][iCanvasWidth];
Complex cSum = new Complex();
if (m_bWriteLog) {
try
{
m_cBufferedWriter.write("m_iIterations[][] =");
m_cBufferedWriter.newLine();
}
catch (IOException ex)
{
System.out.println("Error opening file '" + m_sFileName + "'");
}
}
for (int i = 0; i < iCanvasHeight; i++)
{
for (int j = 0; j < iCanvasWidth; j++)
{
cSum.setRe(m_cCoordPlane[i][j].getRe());
cSum.setIm(m_cCoordPlane[i][j].getIm());
m_iIterations[i][j] = 0;
do
{
m_iIterations[i][j]++;
cSum.square();
cSum.add(m_cSummand);
m_dAbsSqValues[i][j] = cSum.getAbsSq();
} while ((m_iIterations[i][j] < MAXITER) && (m_dAbsSqValues[i][j] < m_iDivergThresh));
this.calcColour(i, j, m_iIterations[i][j]);
m_cMsgIter = "x = " + i + " , y = " + j;
if(m_bWriteLog)
{
System.out.println(m_cMsgIter);
System.out.flush();
}
if (m_bWriteLog) {
try
{
m_cBufferedWriter.write(Integer.toString(m_iIterations[i][j]));
m_cBufferedWriter.write(" ");
}
catch (IOException ex) {
System.out.println("Error writing to file '" + m_sFileName + "'");
}
}
}
if (m_bWriteLog) {
try
{
m_cBufferedWriter.newLine();
}
catch (IOException ex) {
System.out.println("Error writing to file '" + m_sFileName + "'");
}
}
}
m_dAbsSqValues = null;
m_iIterations = null;
cSum = null;
}
private void calcColour(int i, int j, int aIterations)
{
Color cColour = Color.getHSBColor((int) Math.pow(aIterations, 4), 0xff,
0xff * ((aIterations < MAXITER) ? 1 : 0));
m_cCanvas.setPixelColour(i, j, cColour);
cColour = null;
}
private void handleCalculation()
{
Complex cSummand = new Complex();
for(int i = -800; i <= 800; i++)
{
for(int j = -800; j <= 800; j++)
{
cSummand.setRe(((double)i)/1000.0);
cSummand.setIm(((double)j)/1000.0);
this.setSummand(cSummand);
this.calcAbsSqValues();
this.getCanvas().paint(m_cCanvas.getGraphics());
this.paint(this.getGraphics());
}
}
cSummand = null;
this.collectGarbage();
System.gc();
System.runFinalization();
}
public boolean isRunning()
{
return m_bRunning;
}
public void setRunning(boolean aRunning)
{
m_bRunning = aRunning;
}
public Canvas getCanvas()
{
return m_cCanvas;
}
public void run()
{
if(m_bRunning)
{
this.handleCalculation();
}
}
}
class JuliaCanvas extends Canvas
{
private int m_iWidth;
private int m_iHeight;
private Random m_cRnd;
private BufferedImage m_cBackGroundImage = null;
private int m_iRed[][];
private int m_iGreen[][];
private int m_iBlue[][];
JuliaCanvas(int aWidth, int aHeight)
{
m_iWidth = aWidth;
m_iHeight = aHeight;
m_cRnd = new Random();
m_cRnd.setSeed(m_cRnd.nextLong());
m_cBackGroundImage = new BufferedImage(m_iWidth, m_iHeight, BufferedImage.TYPE_INT_RGB);
m_iRed = new int[m_iHeight][m_iWidth];
m_iGreen = new int[m_iHeight][m_iWidth];
m_iBlue = new int[m_iHeight][m_iWidth];
}
public void init() {
}
public void setPixelColour(int i, int j, Color aColour)
{
m_iRed[i][j] = aColour.getRed();
m_iGreen[i][j] = aColour.getGreen();
m_iBlue[i][j] = aColour.getBlue();
}
private int getRandomInt(double aProbability)
{
return (m_cRnd.nextDouble() < aProbability) ? 1 : 0;
}
@Override
public void paint(Graphics aGraphics)
{
// store on screen graphics
Graphics cScreenGraphics = aGraphics;
// render on background image
aGraphics = m_cBackGroundImage.getGraphics();
for (int i = 0; i < m_iWidth; i++)
{
for (int j = 0; j < m_iHeight; j++)
{
Color cColor = new Color(m_iRed[i][j], m_iGreen[i][j], m_iBlue[i][j]);
aGraphics.setColor(cColor);
aGraphics.drawRect(i, j, 0, 0);
cColor = null;
}
}
// rendering is done, draw background image to on screen graphics
cScreenGraphics.drawImage(m_cBackGroundImage, 1, 1, null);
}
@Override
public void update(Graphics aGraphics)
{
paint(aGraphics);
}
}
class Complex {
private double m_dRe;
private double m_dIm;
public Complex()
{
m_dRe = 0;
m_dIm = 0;
}
public Complex(double aRe, double aIm)
{
m_dRe = aRe;
m_dIm = aIm;
}
public Complex(Complex aComplex)
{
m_dRe = aComplex.m_dRe;
m_dIm = aComplex.m_dIm;
}
public double getRe() {
return m_dRe;
}
public void setRe(double adRe)
{
m_dRe = adRe;
}
public double getIm() {
return m_dIm;
}
public void setIm(double adIm)
{
m_dIm = adIm;
}
public void add(Complex acComplex)
{
m_dRe += acComplex.getRe();
m_dIm += acComplex.getIm();
}
public void square()
{
double m_dReSave = m_dRe;
m_dRe = (m_dRe * m_dRe) - (m_dIm * m_dIm);
m_dIm = 2 * m_dReSave * m_dIm;
}
public double getAbsSq()
{
return ((m_dRe * m_dRe) + (m_dIm * m_dIm));
}
}
第一个；
无限循环不是执行此操作的正确方法。这部分是循环并使用 CPU 并且从不给 canvas 来刷新屏幕。如果您添加以下代码，您的代码将按预期 运行。但这不是正确的解决方案。
cMain.java:
while (true) {
cJuliaSet.run();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
其次：您可以在单击开始按钮时调用 运行 方法。但是你应该在 运行 方法中创建一个线程来不冻结屏幕。
public static void main(String[] args) {
int windowWidth = 1000;// (int)screenSize.getWidth() - 200;
int windowHeight = 800;// (int)screenSize.getHeight() - 50;
int plotWidth = 400;// (int)screenSize.getWidth() - 600;
int plotHeight = 400;// (int)screenSize.getHeight() - 150;
JuliaSet cJuliaSet = new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
cJuliaSet.setVisible(true);
//While loop removed
}
执行的动作：
if (strCmd.equals("Start")) {
m_cCanvas.init();
m_cSMsg = "c = " + Double.toString(m_dReal) + " + " + "j*" + Double.toString(m_dImag);
m_bRunning = true;
this.run(); // added call run method.
} else if (aActionEvent.getSource() == m_cTReal) {
运行方法：
public void run()
{
if(m_bRunning)
{
new Thread(){ //Thread to release screen
@Override
public void run() {
JuliaSet.this.handleCalculation();
}
}.start(); //also thread must be started
}
}
正如@RubioRic 所说，SwingUtilities.invokeLater 方法也是解决方案的一部分。但是您需要检查整个代码并且您应该了解线程。
我引用@MadProgrammer 最近的评论（包括链接）
"Swing is single threaded, nothing you can do to change that, all events are posted to the event queue and processed by the Event Dispatching Thread, see Concurrency in Swing for more details and have a look at Worker Threads and SwingWorker for at least one possible solution"
您的代码中只有一个线程。该线程正忙于计算，无法响应 GUI 中的事件。您必须在另一个线程中分离计算，该线程定期更新 window 中出现的数量。我坚持在链接中提供有关此内容的更多信息，由@MadProgrammer 提供。
更新：正如@Yusuf 所指出的，启动 JFrame 的正确方法是
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new JuliaSet("Julia Set", windowWidth, windowHeight, plotWidth, plotHeight);
}
});
设置框架在构建时可见，并在按下开始按钮时开始计算。