IB_DESIGNABLE 和 IBInspectable 的用法

先贴出代码：

CircleView.h

#import <Cocoa/Cocoa.h>

IB_DESIGNABLE
@interface CircleView : NSView
@property (nonatomic, assign) IBInspectable CGFloat lineWidth;
@property (nonatomic, assign) IBInspectable CGFloat radius;
@property (nonatomic, strong) IBInspectable NSColor *color;
@property (nonatomic, assign) IBInspectable BOOL fill;
@end

CircleView.m

#import "CircleView.h"
@implementation CircleView
- (void)drawRect:(NSRect)dirtyRect {    
    // 圆心
    CGFloat centerX = (self.bounds.size.width - self.bounds.origin.x) / 2;
    CGFloat centerY = (self.bounds.size.height - self.bounds.origin.y) / 2;
    NSBezierPath *path = [[NSBezierPath alloc] init];
    // 添加一个圆形
    [path appendBezierPathWithArcWithCenter:CGPointMake(centerX, centerY) radius:_radius startAngle:0 endAngle:360 clockwise:NO];
    [path fill];
    // 设置线条宽度
    path.lineWidth = _lineWidth;
    // 设置线条颜色
    [_color setStroke];
     //绘制线条
    [path stroke];
    if (_fill) {
        // 如果是实心圆，设置填充颜色
        [_color setFill];
        // 填充圆形
        [path fill];
    }
}
@end

• IB_DESIGNABLE 修饰可使view在XIB中预览。

• IBInspectable 属性修饰可在xib中设置属性值。

  
  

swift中@IBInspectable和@IBDesignable的使用

// 给uivew写一个扩展，定义三个属性
extension UIView {
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return self.layer.cornerRadius
        }
        set {
            self.layer.cornerRadius = newValue
            self.layer.masksToBounds = newValue > 0
        }
    }
    
    @IBInspectable var borderWidth: CGFloat {
        get {
            return self.layer.borderWidth
        }
        set {
            self.layer.borderWidth = newValue
        }
    }
    
    @IBInspectable var borderColor: UIColor {
        get {
            return UIColor(cgColor: self.layer.borderColor!)
        }
        set {
            self.layer.borderColor = newValue.cgColor
        }
    }
}

// 自定义view，用@IBDesignable修饰
@IBDesignable class MyView: UIView {
}