将JPanel Graphics导出为.png或.gif或.jpg

Question

我正在尝试使用Java开发某种绘画.

我有一个位于JPanel内的JComponent.

我已经可以在该JComponent中绘制线条和矩形.

现在,我如何将这些图纸导出为图像(png,gif,jpg)？

我试过这个:

BufferedImage b = new BufferedImage(1700,1100,BufferedImage.TYPE_INT_RGB);
this.print(getGraphics());
try{ImageIO.write(b,"png",new File("test.png"));}catch (Exception e) {}

但这只会创建一个全黑的.png文件.

救命!!!

解决!!!

BufferedImage bi = new BufferedImage(this.getSize().width, this.getSize().height, BufferedImage.TYPE_INT_ARGB); 
Graphics g = bi.createGraphics();
this.paint(g);  //this == JComponent
g.dispose();
try{ImageIO.write(bi,"png",new File("test.png"));}catch (Exception e) {}

Answer 1

首先,print()是不正确的方法.我猜应该工作(尚未测试)是:获取BufferedImage的图形(b.createGraphics())并将该图形对象用于paint()您的面板/组件.

(例如yourPanel.paint(b.createGraphics());)