draw() {

             var scale = (editor && editor.canvas && editor.canvas.canvasImp.scale) || 1;//获取当前画布缩放比

             var B = .05;

             var t = 50;

             for (var e = 50 * scale; e >= 200;) // 放大

             {

                 e /= 4;

                 t = e / scale;

             }

             for (; 50 > e;) //缩小

             {

                 e *= 4;

                 t = e / scale;

             }

             var i = B + (e - 50) / 150 * (.07 - B);//颜色值

             this.clear(0, 0, this.canvasWidth, this.canvasHeight);//清空画布

             this.drawGrid(t, i + 0.03);//绘制小格子

             this.drawGrid(t * 4, .21 - i);//绘制大格子

         }

         private drawGrid(e, i) {//e表示每两条线的间隔距离值；i颜色值，大格子的颜色和小格子的颜色值不同

             var P = "rgba(0,0,0,";

             var l = P + i + ")", t = 0;

             var scale = (editor && editor.canvas && editor.canvas.canvasImp.scale) || 1;

             this.context2D.beginPath();

             //为优化性能，控制只绘制当前画面大小的网格线

             var b = this.getLimits();

             var winInfo = getWindow();

             var viewMinx = 0;

             var viewMiny = 0;

             var viewMaxx = winInfo.width;

             var viewMaxy = winInfo.height;

             var isDraw = false;

             var windowViewPoints = new Common.List<Core.Point>();

             windowViewPoints.add(new Core.Point(viewMinx, viewMiny));

             windowViewPoints.add(new Core.Point(viewMaxx, viewMaxy));

             windowViewPoints.add(new Core.Point(viewMinx, viewMaxy));

             windowViewPoints.add(new Core.Point(viewMaxx, viewMiny));

             var that = this;

             var minX = 0, maxX = 0, minY = 0, maxY = 0;//最大、最新 x y值

             windowViewPoints.foreach((index, item: Core.Point) => {

                 var point = that.context2D.transformedPoint(item.x, item.y);

                 if (index == 0) {

                     maxX = minX = point.x;

                     minY = maxY = point.y;

                 }

                 else {

                     minX = minX > point.x ? point.x : minX;

                     maxX = maxX < point.x ? point.x : maxX;

                     minY = minY > point.y ? point.y : minY;

                     maxY = maxY < point.y ? point.y : maxY;

                 }

             });

             //纵向线条

             t = b.minX;

             while (true) {

                 if (Math.abs(t - minX) <= e || t >= minX) {

                     this.context2D.moveTo(t, minY);

                     this.context2D.lineTo(t, maxY);

                 }

                 t = t + e;

                 if (t >= maxX) break;

             }

             //横向线条

             t = b.minY;

             while (true) {

                 if (Math.abs(t - minY) <= e || t >= minY) {

                     this.context2D.moveTo(minX, t);

                     this.context2D.lineTo(maxX, t);

                 }

                 t = t + e;

                 if (t >= maxY) break;

             }

             this.context2D.closePath();

             this.context2D.strokeStyle = l;

             this.context2D.lineWidth = 1 / scale;

             this.context2D.stroke();

         }