UIView动画块未等待

[UIView animateWithDuration:0.8
                             animations:^{ 
                                 [self methodToRun];
                             } 
                             completion:^(BOOL finished){
                                 [self anotherMethod];
                             }];

0.8

dispatch_time_t delay = dispatch_time(DISPATCH_TIME_NOW, NSEC_PER_SEC * 0.8); 
dispatch_after(delay, dispatch_get_main_queue(), ^(void){
    [self anotherMethod];
});