Swift Runtime ？

RunTime简称运行时。OC就是运行时机制，也就是在程序运行时候的一些机制，其中最主要的是消息机制。对于我们熟悉的C语言，函数的调用在编译的时候会决定调用哪个函数。但对于OC的函数，属于动态调用过程，在编译的时候并不能决定真正调用哪个函数，只有在真正运行的时候才会根据函数的名称找到对应的函数来调用。

也就有了下面这两点结论：

1、在编译阶段，OC可以调用任何函数，即使这个函数并未实现，只要声明过就不会报错。

2、在编译阶段，C语言调用未实现的函数就会报错。

看看Swift  Runtime

class TestASwiftClass{ var aBoll :Bool = true
var aInt : Int = 0
func testReturnVoidWithaId(aId : UIView) { print("TestASwiftClass.testReturnVoidWithaId")
}
}

class ViewController: UIViewController{ let testStringOne = "testStringOne"
let testStringTwo = "testStringTwo"
let testStringThr = "testStringThr"
var count:UInt32 = 0 override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view. let SwiftClass = TestASwiftClass()
let proList = class_copyPropertyList(object_getClass(SwiftClass),&count)
for i in 0..<numericCast(count) { let property = property_getName(proList?[i]);
print("属性成员属性:%@",String.init(utf8String: property!) ?? "没有找到你要的属性");
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}

let proList = class_copyPropertyList(object_getClass(self),&count)
for i in 0..<numericCast(count) { let property = property_getName(proList?[i]);
print("属性成员属性:%@",String.init(utf8String: property!) ?? "没有找到你要的属性");
}

class TestASwiftClass{ dynamic var aBoll :Bool = true
var aInt : Int = 0
dynamic func testReturnVoidWithaId(aId : UIView) { print("TestASwiftClass.testReturnVoidWithaId")
}
}

let mthList = class_copyMethodList(object_getClass(SwiftClass),&count)
for index in 0..<numericCast(count) { let method = method_getName(mthList?[index])
print("属性成员方法:%@",String.init(NSStringFromSelector(method!)) ?? "没有找到你要的方法")
}

let IvarList = class_copyIvarList(object_getClass(SwiftClass),&count)
for index in 0..<numericCast(count) { let Ivar = ivar_getName(IvarList?[index])
print("属性成员变量:%@",String.init(utf8String: Ivar!) ?? "没有找到你想要的成员变量")
}

let protocalList = class_copyProtocolList(object_getClass(self),&count)
for index in 0..<numericCast(count) { let protocal = protocol_getName(protocalList?[index])
print("协议:%@",String.init(utf8String: protocal!) ?? "没有找到你想要的协议")
}

func ChangeMethod() -> Void { // 获取交换之前的方法
let originaMethodC = class_getInstanceMethod(object_getClass(self), #selector(self.originaMethod))
// 获取交换之后的方法
let swizzeMethodC = class_getInstanceMethod(object_getClass(self), #selector(self.swizzeMethod)) //替换类中已有方法的实现,如果该方法不存在添加该方法
//获取方法的Type字符串(包含参数类型和返回值类型)
//class_replaceMethod(object_getClass(self), #selector(self.swizzeMethod), method_getImplementation(originaMethodC), method_getTypeEncoding(originaMethodC)) print("你交换两个方法的实现")
method_exchangeImplementations(originaMethodC, swizzeMethodC)
} dynamic func originaMethod() -> Void { print("我是交换之前的方法")
} dynamic func swizzeMethod() -> Void { print("我是交换之后的方法")
}

extension UINavigationBar { var navigationGradualChangeBackgroundView:UIView?{ get{
return objc_getAssociatedObject(self, &self.navigationGradualChangeBackgroundView) as? UIView;
}
set{ objc_setAssociatedObject(self, &self.navigationGradualChangeBackgroundView, navigationGradualChangeBackgroundView, objc_AssociationPolicy.OBJC_ASSOCIATION_COPY_NONATOMIC)
}
} func setNavigationBackgroundColor (backgroundColor: UIColor) -> Void { if (self.navigationGradualChangeBackgroundView == nil) { self.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
self.navigationGradualChangeBackgroundView = UIView.init(frame: CGRect.init(x: 0, y: -20, width: SCREENWIDTH, height: self.bounds.size.height + 20))
self.navigationGradualChangeBackgroundView!.isUserInteractionEnabled = false
self.insertSubview(self.navigationGradualChangeBackgroundView!, at: 0)
} self.navigationGradualChangeBackgroundView!.backgroundColor = backgroundColor
} func removeNavigationBackgroundColor() -> Void { self.setBackgroundImage(nil, for: UIBarMetrics.default)
self.navigationGradualChangeBackgroundView!.removeFromSuperview()
self.navigationGradualChangeBackgroundView = nil
}
}