ios - 快速从调用者到被调用者的回调函数

Question

我有一个 View Controller 和一个类，用于执行调用服务并从服务器获取数据的操作。 ViewController 代码如下，

class ViewController : UIViewController
{

override func viewDidLoad() {
let parser  = Parser()
parser.connectServer("abc URL" , ..... <gotDataFromServer> ..... )
}

func gotDataFromServer(response:String)
{
...... Do our things here .......
}    
}

解析器代码如下，

class Parser
{
func connectServer(apiURL:String,...<call back function name>...)
    {
        let manager = RequestOperationManager.sharedManager()
        manager.GET(apiURL ,
            parameters: nil,
            success: { (operation,responseObject) ->Void in
                    .....<Call back the function which is passed in parameter> ....
            },
            failure: { (operation , error) in
               print ("error occurred")
        })
    }
}

现在，在上面的示例代码中，我想传递回调函数“gotDataFromServer”作为参数，当内部函数从服务器获取响应时，我想回调该函数。 任何人都可以帮忙吗？

Answer 1

您可以使用委托(delegate)来实现这一点。试试下面的代码

class ViewController : UIViewController, DataDelegate
{

override func viewDidLoad() {
let parser  = Parser()
parser.delegate = self
parser.connectServer("abc URL" , ..... <gotDataFromServer> ..... )
}

func gotDataFromServer(response:String)
{
...... Do our things here .......
}    
}

并在解析器中添加如下协议(protocol)

protocol DataDelegate {
    func gotDataFromServer(response:String)
}
class Parser
{
var delegate : DataDelegate!
func connectServer(apiURL:String,...<call back function name>...)
    {
        let manager = RequestOperationManager.sharedManager()
        manager.GET(apiURL ,
            parameters: nil,
            success: { (operation,responseObject) ->Void in
                    delegate.gotDataFromServer("") //parameter is your data
            },
            failure: { (operation , error) in
               print ("error occurred")
        })
    }
}