对于我的应用程序,我需要动态创建网站的缩略图.到目前为止,我有这样的代码从SO：
public class CreateWebsiteThumbnail {
private static final int WIDTH = 128;
private static final int HEIGHT = 128;
private BufferedImage image = new BufferedImage(WIDTH,HEIGHT,BufferedImage.TYPE_INT_RGB);
public void capture(Component component) {
component.setSize(image.getWidth(),image.getHeight());
Graphics2D g = image.createGraphics();
try {
component.paint(g);
} finally {
g.dispose();
}
}
private BufferedImage getScaledImage(int width,int height) {
BufferedImage buffer = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffer.createGraphics();
try {
g.drawImage(image,width,null);
} finally {
g.dispose();
}
return buffer;
}
public void save(File png,int width,int height) throws IOException {
ImageIO.write(getScaledImage(width,height),"png",png);
}
public static void main(String[] args) throws IOException {
Shell shell = new Shell();
Browser browser = new Browser(shell,SWT.EMBEDDED);
browser.setUrl("http://www.google.com");
CreateWebsiteThumbnail cap = new CreateWebsiteThumbnail();
cap.capture(What her?);
cap.save(new File("foo.png"),64,64);
}
}
解决方法
我没看到,你提供的代码可以如何工作. Shell没有打开,没有大小,浏览器没有时间实际加载任何东西,没有事件循环似乎运行,以启用任何绘图,…
import java.io.IOException;
import org.eclipse.swt.SWT;
import org.eclipse.swt.browser.Browser;
import org.eclipse.swt.browser.ProgressEvent;
import org.eclipse.swt.browser.ProgressListener;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageLoader;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class CreateWebsiteThumbnail {
private static final int WIDTH = 800;
private static final int HEIGHT = 600;
public static void main( String[] args ) throws IOException {
final Display display = new Display();
final Shell shell = new Shell();
shell.setLayout(new FillLayout());
final Browser browser = new Browser(shell,SWT.EMBEDDED);
browser.addProgressListener(new ProgressListener() {
@Override
public void changed( ProgressEvent event ) {}
@Override
public void completed( ProgressEvent event ) {
shell.forceActive();
display.asyncExec(new Runnable() {
@Override
public void run() {
grab(display,shell,browser);
}
});
}
});
browser.setUrl("http://www.google.com");
shell.setSize(WIDTH,HEIGHT);
shell.open();
while ( !shell.isDisposed() ) {
if ( !display.readAndDispatch() ) display.sleep();
}
display.dispose();
}
private static void grab( final Display display,final Shell shell,final Browser browser ) {
final Image image = new Image(display,browser.getBounds());
GC gc = new GC(browser);
gc.copyArea(image,0);
gc.dispose();
ImageLoader loader = new ImageLoader();
loader.data = new ImageData[] { image.getImageData() };
loader.save("foo.png",SWT.IMAGE_PNG);
image.dispose();
shell.dispose();
}
}
但有一些严重的警告：
>你不能在屏幕外做这个. SWT截图只是当前显示的副本.
>屏幕截图时,包含浏览器的窗口必须位于顶部.
>该页面应该在onLoad之后可见(实际上并不是google.com的情况,但是由于asyncExec调用,对我而言 – 如果您获得了白色图像,请尝试另一个URL)
>结果取决于您的操作系统及其安装的浏览器
