Objective-C(Swift) IBDesignable/IBInspectable

iOS8新特性IBDesignable/IBInspectable，利用运行时机制，可以把属性映射到XIB上了，同时我们UI类的自定义属性也可以映射上去，可以直接在XIB或者Storyboard中设置UI类的属性。

Objective-C实例：
.h中代码如下

@interface ZWView : UIView@property (nonatomic, assign)IBInspectable CGFloat cornerRadius;@property (nonatomic, assign)IBInspectable CGFloat bwidth;@property (nonatomic, assign)IBInspectable UIColor *bcolor;@end

.m中代码：

#import "ZWView.h"IB_DESIGNABLE@implementation ZWView- (void)setCornerRadius:(CGFloat)cornerRadius{    _cornerRadius = cornerRadius;    self.layer.cornerRadius  = _cornerRadius;    self.layer.masksToBounds = YES;}- (void)setBcolor:(UIColor *)bcolor{    _bcolor = bcolor;    self.layer.borderColor = _bcolor.CGColor;}- (void)setBwidth:(CGFloat)bwidth {    _bwidth = bwidth;    self.layer.borderWidth = _bwidth;}-(void)drawRect:(CGRect)rect{    NSString *drawString = @"www.baidu.com";    [drawString drawInRect:CGRectMake(20, 20, 180, 30) withFont:[UIFont systemFontOfSize:12.0]];}@end

在xib中拖入一个View，设置class为ZWView，设置完后便可以在xib中看到三个属性值

设置三个属性值后，效果如下：

Swift实例:

同样创建一个ZWView，代码如下：

import UIKit@IBDesignable class zwView: UIView {    @IBInspectable var cornerRadius:CGFloat = 0.0 {        didSet{           layer.cornerRadius = cornerRadius           layer.masksToBounds = true        }    }    @IBInspectable var borderColor:UIColor = UIColor(){        didSet{          layer.borderColor = borderColor.CGColor        }    }    @IBInspectable var borderWith :CGFloat = 0.0{        didSet{           layer.borderWidth = borderWith        }    }}

在xib中拖入View,设置class和属性值

效果如下：