block格式_typedef: 返回值(^block名字)(参数)

(1)定义block
typedef void(^myBlcok)(NSArray *array);
(2)申明block属性
@property (strong, nonatomic) myBlcok block;
用block存储值
NSArray *array=[[NSArray alloc]initWithObjects:_userNameText.text,_passWordText.text ,nil];
if (self.block)
{
  self.block(array);
}
 拿到block的值
VC.block=^(NSArray *array){
    _userNameText.text=array[0];
    _passWordText.text=array[1];
};

闭包_typealias

  1.首先，创建闭包类型
   typealias SwiftBlock = (phone:String?, password:String?) -> Void
  2.定义闭包函数变量
  private var block:SwiftBlock?
  3.声明含有闭包变量的函数
  func setTitle(title: String, account: SwiftBlock){   
      navigationItem.title = title
      self.account = account
  }
  4.触发闭包函数
  if let nameAndPassword = account {    
      nameAndPassword(phone: phone, password: password)
  }
  5.闭包回调
  VC.setTitle("登录界面") { (phone, password) in 
      print("phone:\(phone)password:\(password)")
  }