SWT实现透明背景代码

来源：互联网发布：网络使用调查问卷编辑：程序博客网时间：2024/04/29 17:54
import org.eclipse.swt.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.layout.FillLayout;import org.eclipse.swt.widgets.*;import org.eclipse.swt.events.*;public class Talpha {        /**         * @param args         */        public static void main(String[] args) {                // TODO Auto-generated method stub                final Display display = new Display();                final Shell shell = new Shell(display);                Canvas canvas = new Canvas(shell, SWT.NO_BACKGROUND);                //使用paintlistener，保证每次均重新绘制。                canvas.addPaintListener(new PaintListener() {                        public void paintControl(PaintEvent e) {                                GC gc = e.gc;                        //读图像                        ImageData imageData = new ImageData("t.jpg");                                 //这里是建立从左到右的渐进Alpha。                   byte[] alphaValues = new byte[imageData.height * imageData.width];                                for (int j = 0; j < imageData.height; j++) {                                        for (int i = 0; i < imageData.width; i++) {                              alphaValues[j * imageData.width + i] = (byte) (255 - 255                                                                * i / imageData.width);                                        }                                }                                imageData.alphaData = alphaValues;                                Image image = new Image(display, imageData);                         //绘制                                                       gc.drawImage(image,0,0);                        }                });                FillLayout fillLayout = new FillLayout();                fillLayout.type = SWT.VERTICAL;                shell.setLayout(fillLayout);                shell.setSize(200, 600);                shell.open();                while (!shell.isDisposed()) {                        if (!display.readAndDispatch())                                display.sleep();                }                display.dispose();        } }