swift（闭包）

定义闭包属性

 var block02 = {
        (str1:String,str2:String)in
       //TODO:Do something
    }

或

func myblock(str:String) -> Void {
    
}
var block03:(String)->Void = myblock

或直接构建

var block06:((String)->Void)!

let blvc = BlockVC()
 blvc.block02 = {
                (str:String,str2:String) in
               
                print(str+str2)
            
            }
 blvc.block03 = {
                (str:String) in
                
                print(str)
                
            }
 blvc.block06({ (str) in
                print(str)
                
            })

闭包函数

  func block01(str:String,block:(String) -> Void) ->Void {
        print(str)
        block("这是block")
    }

调用

blvc.block01(str:"传值", block: { (str) in
                
                print("读取block回调的东西\(str)")
                
            })

逃逸闭包（@escaping）

    /// 定义可以逃逸闭包的block的函数
    /// - Parameters:
    /// - str: 传入值
    /// - block: block
    func block04(str:String,block:@escaping(String)-> Void) -> Void {
       print(str)
       self.block05 = block//@escaping可以让block的指向跳出函数
    
    }

调用

     blvc.block04(str:"第四种block使用", block: { (str) in
                print(str)
            })