Collision Being Detected before Collision Takes Place - objective-c

Question

In the following code I try and to detect if the code is actually detecting collision. But before the bullet and line collides, the debugger says "Collided!"
//Collision Detector
-(BOOL)viewsDoCollide {
if(CGRectIntersectsRect(_bullet.frame, _line.frame)) {
return YES;
} else {
return NO;
}
}
//So that the turrets shoot
- (IBAction)shooterButton:(id)sender {
[self mover:(id)sender];
}
- (void)mover:(id)sender {
CGRect bulletFrame = _bullet.frame;
CGRect lineFrame = _line.frame;
[UIView animateWithDuration:2 animations:^{
CGRect newFrame = CGRectMake(bulletFrame.origin.x + lineFrame.origin.x - 14, bulletFrame.origin.y, bulletFrame.size.width, bulletFrame.size.height);
_bullet.frame = newFrame;
}];
bool collisionDetector = [self viewsDoCollide];
if (collisionDetector == YES) {
NSLog(#"Collided!");
}
}
I presume the collision is "taking place" before it does because I have a set position for the bullet. How do I "shoot" the bullet without using [UIView animateWithDuration]? Or, how do I actually get the code to detect the collision when it actually happens?

Answer 1

Your collision detection code is not within the animation that is running. You've asked the OS to animate from one frame to another, which will happen after this function has returned (on the UI thread).
So, you're detecting collisions before the animation has started.
If you want to do a 2D game, I recommend using something like Cocos2D. It has high-level support for what you want to do.