the boy just can only move in the horizontal direction when i add a right force，I want him to walk along the line I draw…so you know ,when the boy arrive the line he does not move at all,i do not know if i should add a vertical force …Ok,My english is poor ,Don’t care about grammar problems…
ok , the problem is solved, its my fault ,i just need add force at the vector2(0.5f,0.5f)