Comparison between CGRectInset and CGRectOffset for iOS development

1. CGRectInset

 
 

  
  
CGRect CGRectInset ( 
  
  
CGRect rect, 
  
  
CGFloat dx, 
  
  
CGFloat dy 
  
  
); 
 
 

The application of this struct is centered on the original rect. See dx and dy for scaling or amplification.

Each rectangle in the image is the above rectangle as the reference rectangle. So the next rectangle, such as the yellow rectangle, is the next rectangle for the green rectangle.) It is smaller than the previous rectangle. The specific small part should be determined by referring to dx and dy.

2. CGRectOffset

 
 

  
  
CGRect CGRectOffset( 
  
  
CGRect rect, 
  
  
CGFloat dx, 
  
  
CGFloat dy 
  
  
); 
 
 

Offset from the point in the upper left corner of the rect at the source rectangular origin) along the X and Y axes, and then along the X and Y axes on the basis of the rect

 
 

  
  
float offset = 125.0; 
  
  
CGRect r1 = CGRectMake(100, 100, 5, 5); 
  
  
CGRect r2 = CGRectOffset(r1, offset, offset); 
 
 

3. frame and dounds

Frame and bounds are two properties in UIView ).

 
 

  
  
-(CGRect)frame{ 
  
  
return CGRectMake(self.frame.origin.x,self.frame.origin.y,self.frame.size.width,self.frame.size.height); 
  
  
} 
  
  
-(CGRect)bounds{ 
  
  
return CGRectMake(0,0,self.frame.size.width,self.frame.size.height); 
  
  
} 
 
 

Frame indicates the position and size of the view in the parent view coordinate system. The reference point is the father's coordinate system)

Bounds indicates the position and size of the view in its own coordinate system. The reference point is its own coordinate system)