这是我对GWT和HTML5 Canvas的第一个实验。 我的第一个尝试是创建矩形，仅用几行代码就得出了这样的内容：

码：

public class GwtHtml5 implements EntryPoint {static final String canvasHolderId = "canvasholder";static final String unsupportedBrowser = "Your browser does not support the HTML5 Canvas";static final int height = 400;static final int width = 500;final CssColor colorRed = CssColor.make("red");final CssColor colorGreen = CssColor.make("green");final CssColor colorBlue = CssColor.make("blue");Canvas canvas;Context2d context;public void onModuleLoad() {canvas = Canvas.createIfSupported();if (canvas == null) {RootPanel.get(canvasHolderId).add(new Label(unsupportedBrowser));return;}createCanvas();}private void createCanvas(){canvas.setWidth(width + "px");canvas.setHeight(height + "px");canvas.setCoordinateSpaceWidth(width);canvas.setCoordinateSpaceHeight(height);RootPanel.get(canvasHolderId).add(canvas);context = canvas.getContext2d();context.beginPath();context.setFillStyle(colorRed);context.fillRect(100, 50, 100, 100);context.setFillStyle(colorGreen);context.fillRect(200, 150, 100, 100);context.setFillStyle(colorBlue);context.fillRect(300, 250, 100, 100);context.closePath();}}

我的Spring Ball尝试了一些我在Web上找到的代码。

参考：来自GlyphSoft博客的JCG合作伙伴 Mark Anro Silva的GWT和HTML5 Canvas演示 。