IOS sets a font for the entire App, but does not specify the font size.

UIFont

Parameters

FontSize

The size (in points) to which the font is scaled. This value must be greater than 0.0.

The actual fontSize parameter is pointSize, which is a pixel.

The font size on windows and mac is consistent.

The English font is equivalent to 1/72 inch, which is about 1/2. 8mm.

12 pt words are printed at about 4.2mm. 12 PX is equivalent to 12 pixels.

Although 4th = (14/72) * 96 = 18.6px is closer to 19px, because 18px is a dot matrix, the system displays the dot matrix size first.

In other words: 4 = 18px

Chinese font size VS English font size (lbs) VS pixel value

The following code is used to set a font for the entire App in iOS development without specifying the font size:

 
 

  
  
- (void)viewDidLoad 
  
  
{ 
  
  
    [super viewDidLoad]; 
  
  
    [self setFontFamily:@"FagoOfficeSans-Regular" forView:self.view andSubViews:YES]; 
  
  
} 
  
  
 
  
  
-(void)setFontFamily:(NSString*)fontFamily forView:(UIView*)view andSubViews:(BOOL)isSubViews 
  
  
{ 
  
  
    if ([view isKindOfClass:[UILabel class]]) 
  
  
    { 
  
  
        UILabel *lbl = (UILabel *)view; 
  
  
        [lbl setFont:[UIFont fontWithName:fontFamily size:[[lbl font] pointSize]]]; 
  
  
    } 
  
  
 
  
  
    if (isSubViews) 
  
  
    { 
  
  
        for (UIView *sview in view.subviews) 
  
  
        { 
  
  
            [self setFontFamily:fontFamily forView:sview andSubViews:YES]; 
  
  
        } 
  
  
    }     
  
  
}