initWithDelegate for Objective-C類

Question

我已經在一個swift項目中導入了這個Objective-C類。 MMLANSCanner.h

#import <Foundation/Foundation.h> 

@class Device; 
@protocol MMLANScannerDelegate; 
@protocol MMLANScannerDelegate <NSObject> 
@required 
- (void)lanScanDidFinishScanningWithStatus:(MMLanScannerStatus)status; 
- (void)lanScanDidFailedToScan; 
@optional 
- (void)lanScanProgressPinged:(float)pingedHosts from:(NSInteger)overallHosts; 
@end 

#pragma mark - Public methods 
@interface MMLANScanner : NSObject 
-(instancetype)initWithDelegate:(id <MMLANScannerDelegate>)delegate; 
@property(nonatomic,weak) id<MMLANScannerDelegate> delegate; 
@property(nonatomic,assign,readonly)BOOL isScanning; 
- (void)start; 
- (void)stop; 
@end 

我成功創建了橋接報頭，使MainVC.Swift符合MMLANScannerDelegate。 然後我試着用代理self初始化MMLanScanner。

import UIKit 
import Foundation 

class MainVC: UIViewController, MMLANScannerDelegate { 

    var presenter = MMLANScanner(delegate:self) 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     // Do any additional setup after loading the view. 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 

    func lanScanDidFindNewDevice(_ device: Device!) { 

    } 

    func lanScanDidFailedToScan() { 

    } 

    func lanScanDidFinishScanning(with status: MMLanScannerStatus) { 

    } 

    func lanScanProgressPinged(_ pingedHosts: Float, from overallHosts: Int) { 

    } 
} 

，但我得到的錯誤：

Argument passed to call that takes no arguments

任何想法如何實現initWithDelegate功能，我不得不在Objective-C？

Answer 1

MLANScanner不採取delegate參數其init方法（delegate是屬性的MLANScanner）。

您的presenter屬性的定義也存在問題，因爲self在創建時MainVC時無效。

而是執行此操作：

let presenter = MLANScanner() 

override func viewDidLoad() { 
    super.viewDidLoad() 

    presenter.delegate = self 
} 

基於編輯質疑：

var presenter: MLANScanner! 

override func viewDidLoad() { 
    super.viewDidLoad() 

    presenter = MLANScanner(delegate: self) 
} 

注：我的編輯答案假設有一個斯威夫特橋的地方，暴露了一個init(delegate:)方法。有可能沒有，超出了這個問題的範圍。由於代理不是私有的或只讀的，您幾乎可以肯定使用我發佈的第一個版本。