首先,图像的大小应该是树没有滚动时的大小,而不是当前大小。为此,您应该使用computeSize(SWT.DEFAULT, SWT.DEFAULT, true)
. 然后你应该调整树的大小,打印,然后重新调整大小。由于您不希望用户注意到这一点,因此在此操作期间您应该禁用绘图setRedraw(false)
。
这是一个完整的片段,可以完成所有这些:
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
Composite composite = new Composite(shell, SWT.NONE);
composite.setLayout(new FillLayout());
final Tree tree = new Tree(composite, SWT.NONE);
for (int i = 0; i < 100; i++) {
final TreeItem treeItem = new TreeItem(tree, SWT.NONE);
treeItem.setText(String.format("item %d long name", i));
}
tree.addListener(SWT.DefaultSelection, new Listener() {
@Override
public void handleEvent(Event event) {
tree.getParent().setRedraw(false);
final Point originalSize = tree.getSize();
final Point size = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
final Image image = new Image(display, size.x, size.y);
final GC gc = new GC(image);
tree.setSize(size);
tree.print(gc);
tree.setSize(originalSize);
final ImageLoader loader = new ImageLoader();
loader.data = new ImageData[]{image.getImageData()};
final String pathToSave = "out.png";
System.out.println(new File(pathToSave).getAbsolutePath());
loader.save(pathToSave, SWT.IMAGE_PNG);
gc.dispose();
image.dispose();
tree.getParent().setRedraw(true);
}
});
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
按回车键保存文件。