【发布时间】：2012-01-02 09:18:18
【问题描述】：
我正在绘制模拟正在生成的信息的图形表示。我有图表显示，但我遇到的问题是能够将其保存为.png。当它保存png时，文件全是黑色的，所以它不是保存我的图形而是创建一些空白的png文件。问题是我很难弄清楚如何转换为 BufferedImage 或 RenderedImage 我在 eclipse 中的所有尝试都会抛出错误，当我编译它时，它就像我上面描述的那样工作。有什么想法或建议吗？我已经坚持了几个星期，要么这是一个明显的修复，要么我无法将它保存为 png。但是根据我进行的研究，可以将 java 2d 图形 img 保存为 png 文件，我不知道我错过了什么？一双新鲜的眼睛将不胜感激！在此先感谢您，感谢您对此提出的任何建议或建议。
public class GraphDisplay extends JPanel implements RenderedImage {
final int PAD = 20;
Primate p;
public GraphDisplay(){
}
public GraphDisplay(Primate p){
this.p = p;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// now we can get x1,y1,x2,y2
double tlx= p.getMap().getX1();
double tly= p.getMap().getY1();
double brx= p.getMap().getX2();
double bry= p.getMap().getY2();
int w = getWidth();
int h= getHeight();
ArrayList <Tree> t= p.getMap().getTrees();
ArrayList<Double> xHist = p.getXHist();
ArrayList<Double> yHist = p.getYHist();
ArrayList<Double> testxHist = new ArrayList();
ArrayList<Double> testyHist = new ArrayList();
for(double i=34;i<1000;i+=5)
{
testxHist.add(i);
}
for(double i=34;i<1000;i+=5)
{
testyHist.add(i);
}
// Draw lines.
double scale=.45;
g2.setBackground(Color.WHITE);
g2.setPaint(Color.green.darker());
for(int i = 0; i < xHist.size()-1; i++) {
double x1 = PAD + (xHist.get(i)-tlx)*scale;
double y1 = (tly-yHist.get(i))*scale-PAD;
double x2 = PAD + (xHist.get(i+1)-tlx)*scale;
double y2 = (tly-yHist.get(i+1))*scale-PAD;
g2.draw(new Line2D.Double(x1, y1, x2, y2));
}
// Mark path points
if(p.getRoute()!=null)
{
ArrayList<Double> routeX= p.getRoute().getX();
ArrayList<Double> routeY= p.getRoute().getY();
g2.setPaint(Color.pink);
for(int i = 0; i < routeX.size()-1; i++) {
double x1 = PAD + (routeX.get(i)-tlx)*scale;
double y1 = (tly-routeY.get(i))*scale-PAD;
double x2 = PAD + (routeX.get(i+1)-tlx)*scale;
double y2 = (tly-routeY.get(i+1))*scale-PAD;
g2.draw(new Line2D.Double(x1, y1, x2, y2));
}
}
g2.setPaint(Color.red);
for(int i = 0; i < xHist.size(); i++) {
double x = PAD + (xHist.get(i)-tlx)*scale;
double y = (tly-yHist.get(i))*scale-PAD;
g2.fill(new Ellipse2D.Double(x-.75, y-.75, 1.5, 1.5));
}
//testing purposes
g2.setPaint(Color.BLACK);
for(int i=0;i<t.size();i++)
{
double x= PAD+(t.get(i).getX()-tlx)*scale;
double y= (tly-t.get(i).getY())*scale-PAD;
g2.fill(new Ellipse2D.Double(x-1,y-1,2,2));
}
}
public class GraphListener implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
saveGraph(p);
}
}
public void saveGraph(Primate p)
{
ImageIcon saveIcon = new ImageIcon("save.png");
GraphDisplay graphImg = new GraphDisplay(p);
Object graph = new GraphDisplay(p);
BufferedImage buffGraph = new BufferedImage(500,500, BufferedImage.TYPE_INT_RGB);
graph = buffGraph.createGraphics();
RenderedImage rendGraph = (RenderedImage) graphImg;
String graphFileName = JOptionPane.showInputDialog("Please enter a name for the S1Mian graphical output file: ");
File f;
f = new File(graphFileName + ".png");
//every run is unique so do not allow the user to overwrite previously saved files...
if(!f.exists())
{
try{
ImageIO.write(buffGraph, "png", f);
JOptionPane.showMessageDialog(null, graphFileName + ".png has been created and saved to your directory...", "File Saved", JOptionPane.INFORMATION_MESSAGE, saveIcon);
}
catch (IOException e)
{
e.printStackTrace();
}
}
else{
JOptionPane.showMessageDialog(null, graphFileName +".png already exists please use a different file name...", "File Exists", JOptionPane.INFORMATION_MESSAGE, saveIcon);
}
}
public void createGraph(Primate p)
{
JFrame frame = new JFrame("S1Mian Graphical Output");
//frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //disabled now that graphical output is integrated into GUI as when clicked shut down entire program...
JPanel savePanel = new JPanel();
ImageIcon saveIcon = new ImageIcon("saveIcon.png");
JButton save = new JButton("Save");
save.setToolTipText("Saves the S1Mian graphical output to a .png file");
save.setIcon(saveIcon);
GraphListener gl = new GraphListener();
save.addActionListener(gl);
GraphDisplay graph = new GraphDisplay(p);
graph.setPreferredSize(new Dimension(950, 900));
JScrollPane graphScrollPane = new JScrollPane();
graphScrollPane.setViewportView(graph);
graphScrollPane.setViewportBorder(BorderFactory.createLineBorder(Color.black));
frame.getContentPane().add(graphScrollPane, BorderLayout.CENTER);
savePanel.add(save);
frame.getContentPane().add(savePanel, BorderLayout.NORTH);
frame.setSize(900,850);
frame.setLocation(200,200);
frame.setVisible(true);
}
【问题讨论】：
标签： java image swing graphics png