开发绘图、手势综合App注意点

-(void) pan: (UIPanGestureRecognizer * ) pan {  CGPoint transP = [pan translationInView: pan.view]; //$1 = (x = 0.73990527317289434, y = 0)  CGPoint pont1 = [pan locationInView: self]; //$2 = (x = 198.16665649414063, y = 342.33332824707031)  CGPoint pont2 = [pan locationInView: self.imageV]; //$3 = (x = 198.12057060663793, y = 342.61609831987914)  pan.view.transform = CGAffineTransformTranslate(pan.view.transform, transP.x, transP.y);  //复位  [pan setTranslation: CGPointZero inView: pan.view];}

[UIView animateWithDuration: 0.25 animations: ^ {    self.imageView.alpha = 0;  }completion: ^ (BOOL finished){    self.imageView.alpha = 1;    UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0);    CGContextRef ctx = UIGraphicsGetCurrentContext();    [self.layer renderInContext: ctx];    UIImage * imageGot = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    [self.imageView removeFromSuperview];    if (self.delegate && [self.delegate respondsToSelector: @selector(handleImageView: didOperatedImage: )]){      [self.delegate handleImageView: self didOperatedImage: imageGot];    }  }];