clear() 删除绘制
lineStyle(width, color, alpha) 设置线条样式
moveTo(x, y)
lineTo(x, y) 以上两个绘制直线
curveTo(x1, y1, x2, y2) 绘制曲线
beginFill(color, alpha)
endFill() 创建图形
beginGradientFill(fillType, colors, alpha, ratios, matrix) 创建渐变填充
drawCircle(x, y, radius)
drawEllipse(x, y, width, height)
drawRect(x, y, width, height)
drawRoundRect(x, y, width, height, ellipseWidth, ellipseHeight)