面积量算工具，用于高斯投影下的多边形面积量算，其中包括两种数学计算方法。-the area-measurement tool is used to measure a polygon s area in gauss projection.it includes two kinds of mathematical algorithm

c#实现的兰勃特投影算法类（直接将经纬度转换到平面坐标）-c# realized Lambert projection algorithm type (directly to the latitude and longitude coordinates of the transition to plane)