Okey,I found the bug.
I set a flag value for just do remapcolumn once in the loadcomplete event, and the remapcolumn loop problem will get resloved.
And the id null bug is clear.
The Colmodel key position of permutation cannot be remap.
ex: the key position is 3 ,the oringnal permutation : [0,1,2,3,4,5,6,7]
after remap just once : [0,7,5,3,4,1,2,6], the id is correct, after reloadgrid the id is corrent.
after remap just once : [0,3,5,7,4,1,2,6], the id is correct, after reloadgrid the id is null.
