Swift利用闭包（closure）来实现传值-->前后两个控制器的反向传值

OC中Blocks反向传值和Swift中Closure反向传值的差别，下面直接贴上代码：@H_301_1@

一、第一个界面@H_301_1@

@H_301_1@

[objc]view plaincopy 
   
 importUIKit 
 
 classZWRootViewController:UIViewController{
 init(nibNamenibNameOrNil:String?,bundlenibBundleOrNil:NSBundle?){
 super.init(nibName:nibNameOrNil,bundle:nibBundleOrNil)
 //Custominitialization
 }
 varmyLabel:UILabel?
 overridefuncviewDidLoad(){
super.viewDidLoad()
 varitem=UIBarButtonItem(title:"下一页",style:UIBarButtonItemStyle.Plain,target:self,action:"nextBtnClicked")
self.navigationItem.rightBarButtonItem=item
 
 myLabel=UILabel(frame:CGRectMake(0,100,320,50))
 myLabel!.text="Closure"
 myLabel!.textAlignment=NSTextAlignment.Center
self.view.addSubview(myLabel!)
//Doanyadditionalsetupafterloadingtheview.
 funcsomeFunctionThatTakesAClosure(string:String)->Void{
 //functionbodygoeshere
 myLabel!.text=string
 funcnextBtnClicked(){
 letsecond=ZWSecondViewController(nibName:nil,bundle:nil)
//将当前someFunctionThatTakesAClosure函数指针传到第二个界面，第二个界面的闭包拿到该函数指针后会进行回调该函数
 second.initWithClosure(someFunctionThatTakesAClosure)
self.navigationController.pushViewController(second,animated:true)
 }
 overridefuncviewWillDisappear(animated:Bool){
 myLabel!.hidden=true
 overridefuncviewWillAppear(animated:Bool){
 myLabel!.hidden=false
 overridefuncdidReceiveMemoryWarning(){
super.didReceiveMemoryWarning()
//DispoSEOfanyresourcesthatcanberecreated.
/*
//#pragmamark-Navigation
//Inastoryboard-basedapplication,youwilloftenwanttodoalittlepreparationbeforenavigation
overridefuncprepareForSegue(segue:UIStoryboardSegue?,sender:AnyObject?){
//Getthenewviewcontrollerusing[seguedestinationViewController].
//Passtheselectedobjecttothenewviewcontroller.
}
*/
 }