测绘中的面积计算。代码是本人自己编写的，实现读取Excel中给定点坐标（按照顺时针或逆时针编号），并计算给定点所围成的区域面积。-Mapping the area. Code is I have written to achieve a given point in Excel to read the coordinates (clockwise or counterclockwise in accordance with the number), and calculate a given p