canvas.drawColor(Color.GREEN);

                 Paint paint1 = new Paint();

                 canvas.drawCircle(40, 30, 20, paint1);

                 //设置画笔无锯齿，默认有锯齿

                 paint1.setAntiAlias(true);

                 canvas.drawCircle(100, 30, 20, paint1);

                 //设置画笔的透明度

                 canvas.drawText("无透明度", 100, 70, new Paint());

                 Paint paint2 = new Paint();

                 paint2.setAlpha(0x77);

                 canvas.drawText("半透明度", 20, 70, paint2);

                 //设置绘制文本的锚点

                 canvas.drawText("锚点", 20, 90, new Paint());

                 Paint paint3 = new Paint();

                 //设置以文本的中心点绘制

                 paint3.setTextAlign(Paint.Align.CENTER);

                 canvas.drawText("锚点", 20, 105, paint3);

                 //获取文本的长度

                 Paint paint4 = new Paint();

                 float len =paint4.measureText("文本宽度:");

                 canvas.drawText("文本长度:"+len, 20, 130, new Paint());

                 //设置画笔样式

                 canvas.drawRect(new Rect(20,140,40,160), new Paint());

                 Paint paint5 = new Paint();

                 //设置画笔不填充

                 paint5.setStyle(Style.STROKE);

                 canvas.drawRect(new Rect(60,140,80,160), paint5);

                 //设置画笔颜色

                 Paint paint6 = new Paint();

                 paint6.setColor(Color.GRAY);

                 canvas.drawText("灰色", 30, 180, paint6);

                 //设置画笔的粗细程度

                 canvas.drawLine(20, 200,70, 200, new Paint());

                 Paint paint7 = new Paint();

                 paint7.setStrokeWidth(7);

                 canvas.drawLine(20, 220,70, 220,paint7);

                 //设置画笔绘制文本的字体粗细

                 Paint paint8 = new Paint();

                 paint8.setTextSize(20);

                 canvas.drawText("文字尺寸", 20, 260, paint8);

                 //设置画笔的ARGB分量 ，a值 (透明度)

                 Paint paint9 = new Paint();

                 paint9.setARGB(0x77, 0xff, 0x00, 0x00);

                 canvas.drawText("红色半透明", 20, 290, paint9);