Add attributes in storyboard and Xib (fillet, foreground...) Ibinspectable and ibdesignable

origin

iOS In development , Engineers are exposed to a lot of view rendering code . For code readability ,iOS Provides information such as xib and storyboard Tools to drag and drop controls , Set constraints . But if we need to set some Round corners , Rich text font color When waiting for attributes , Find out Xcode The attribute list provided is not available . Probably through User Defined Runtime Attributes, This is similar to what we said ***IBInspectable*** of , But it is not elegant .

IBInspectable

You can add the IBInspectable attribute to any property in a class declaration, class extension, or category of type: boolean, integer or floating point number, string, localized string, rectangle, point, size, color, range, and nil.

We can do it in class, extenstion, category Add Inspectable To modify boolean, integer or floating point number, string, localized string, rectangle, point, size, color, range, and nil Properties of type .

Objc Add attributes gracefully in

1. Here, take adding fillets as an example
2. Category Extended attributes
3. Code instance

@interface UIView (JJIBProp)

///  radius 
@property (nonatomic, assign, readwrite) IBInspectable CGFloat cornerRadius;
/// statusbar  Is it hidden 
@property (nonatomic, assign, readwrite) IBInspectable BOOL jjPreferedStatubarHidden;

@end

#import "UIView+JJIBProp.h"

@implementation UIView (JJIBProp)

- (void)setCornerRadius:(CGFloat)cornerRadius {
    self.layer.cornerRadius = cornerRadius;
    self.layer.masksToBounds = cornerRadius > 0;
}

- (CGFloat)cornerRadius {
    return self.layer.cornerRadius;
}

- (BOOL)jjPreferedStatubarHidden {
    return self.jjPreferedStatubarHidden;
}

- (void)setJjPreferedStatubarHidden:(BOOL)jjPreferedStatubarHidden {
    [UIStatusBarManager setShouldGroupAccessibilityChildren:jjPreferedStatubarHidden];
}

Swift

extension UIView {
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }
}

IB It's probably in this style

IBDesginable

This thing can render the view directly , I know so
If you want to write code for a custom view that runs only in Interface Builder, call that code from the prepareForInterfaceBuilder method. For example, while designing an app that uses the iPhone camera, you might want to draw an image that represents what the camera might capture. Interface Builder calls the prepareForInterfaceBuilder method instead of the awakeFromNib method. If you want to share code between these methods, move that code to another method that you call from both of these methods.

Raking a lot probably means ： stay IB You can't get the complete information when running in , You need to prepareForInterfaceBuilder() Method , This method can be compiled with other methods , But only when the view is being prepared in Interface Builder Execute on display .

There's another way ：

In Objective-C and Swift, you can use the preprocessor macro TARGET_INTERFACE_BUILDER to conditionally compile code for your custom view class.

#if !TARGET_INTERFACE_BUILDER
   // Run this code only in the app
#else
   // Run this code only in Interface Builder
#endif