ios - UIView doesn't animate -

i want animate center of uiview, , did in viewdidload:

_test.center = cgpointmake(100.0,100.0); [uiview animatewithduration:10.0          delay:5          options:uiviewanimationoptioncurvelinear          animations:^{_test.center = cgpointmake(100.0,-100.0);}          completion:^(bool finished) {  }]; 

but when run code, center of test view @ 100,-100. why doesn't animate?

move code viewdidload viewdidappear. in viewdidload, uiview has been loaded, not visually present yet.