一些观察结果:
-变量id在两个循环外均已初始化，并且其值在循环内从未更改.但是，它用于确定是否将设置row2值.这是正确的吗?
-内循环遍历目标gridview中每一行的所有源行.反之亦然(循环在源和内部循环，在目标循环中添加值).

Few observations:
- variable id is initialized outside both loops and it''s value is never changed inside the loops. However it''s used to decide if row2 value will be set. Is this correct
- the inner loop goes through all source rows for each row in target gridview. Should the loops vice versa (loop the source and inside that add values in target loop).