如何在Swift 2.0中實現copyWithZone？

Question

下面的代碼被寫入夫特2.0創建的dispatch_block_t

let a: dispatch_block_t = { 
    self.pickImages() 
} 
let b: dispatch_block_t = { 
    self.takePicture() 
} 
let c: dispatch_block_t = { 
    self.pickVideos() 
} 
let d: dispatch_block_t = { 
    self.shootVideo() 
} 
let e: dispatch_block_t = { 
    self.recordAudio() 
} 
let f: dispatch_block_t = { 
    self.closeView() 
} 

let block1 = Block(block: a) 
let block2 = Block(block: b) 
let block3 = Block(block: c) 
let block4 = Block(block: d) 
let block5 = Block(block: e) 
let block6 = Block(block: f) 

let actionsArray: NSArray = [block1, block2, block3, block4, block5, block6] 

一個陣列和Block類被定義如下，

class Block: NSObject, NSCopying { 
    var block: dispatch_block_t 

    init(block: dispatch_block_t){ 
     self.block = block 
    } 

    func copyWithZone(zone: NSZone) -> AnyObject { 
     return self.block as! AnyObject 
    } 
} 

我可以創建dispatch_block_t的陣列與上述片的代碼。但是，我需要將此數組作爲參數傳遞給另一個函數，並且在傳遞此數組時遇到了一個問題。

我呼籲一個按鈕單擊事件這個功能，

menuView = btSimplePopUP(itemImage: imgs as [AnyObject], 
    andTitles: titles as [AnyObject], 
    andActionArray: actionsArray as [AnyObject], 
    addToViewController: self) 

，執行下面的代碼片段時，我得到一個錯誤，

- (instancetype)initWithImage:(UIImage *)image title:(NSString *)title action:(dispatch_block_t)action { 
if ((self = [super init])) { 
    _title = [title copy]; 
    _imageView = [[UIImageView alloc]initWithImage:image]; 
    _action = [action copy]; 
} 

return self; 
} 

和錯誤是，

無法將類型'（） - >（）'（0x15164018）的值轉換爲'Swift.AnyObject'（0x101e500c）。

我得到這個錯誤copyWithZone函數Block類。

爲btSimplePopUp的完整源代碼在這裏可以查看， https://github.com/balram3429/btSimplePopUp/blob/master/btSimplePopUp/btSimplePopUP.m

Answer 1

dispatch_block_t是一個結構，而不是一個對象。實際上它是一個C結構。我不明白你爲什麼需要使用dispatch_block_t，爲什麼不只是傳遞閉包。如果必須將它傳遞給dispatch_函數，請將其包裝在調用站點的dispatch_block_t中。

要Swiftify此：

在夫特，dispatch_block_t是簡單地爲() ->()即一個別名的空隙功能/閉合返回Void。所以，你可以簡單地說

let a = { self.pickImages() } 
// etc 

let actionArray = [ a, b, c, ...] 

然而，pickImages是具有相同類型（在技術上它是咖喱在self但不要擔心這是什麼意思），你可以對A，B忘了這麼一個功能， C位，只是這樣做

let actionArray = [ self.pickImages, self.takePhoto, ... ] 

而且在斯威夫特，你可以在陣列中使用「對象」之一，任何時候你有一個參數，需要一個dispatch_block_t如

dispatch_after(someTime, dispatch_get_main_queue(), actionArray[0]) 

Answer 2

您需要修改您的Objc框架。您的btSimplePopUP應該像ActionContainer一樣從此示例中運行。 ActionObject是Swift dispatch_block_t的裝箱版本。如何在代碼中取消裝箱？請參閱ActionContainer作業功能。

// 
// Actions.h 
// test 
// 


#ifndef Actions_h 
#define Actions_h 
#import <Foundation/Foundation.h> 

@interface ActionObject : NSObject 
@property (nonatomic, copy) dispatch_block_t action; 
@end 


@interface ActionContainer : NSObject 
@property NSArray * actions; 
-(void)job; 
@end 

#endif /* Actions_h */ 

...

// 
// Actions.m 
// test 
// 


#import <Foundation/Foundation.h> 
#import "Actions.h" 


@implementation ActionObject 

-(instancetype)initWithAction: (dispatch_block_t)someaction { 
    if ((self = [super init])) { 
     _action = [someaction copy]; 
    } 
    return self; 
} 

@end 

@implementation ActionContainer 
-(void)job { 
    if (_actions != nil) { 
     NSUInteger count = _actions.count; 
     NSUInteger i; 
     for (i = 0; i < count; i++) { 
      ActionObject *action = _actions[i]; 
      action.action(); 
     } 

    } 
} 

@end 

...

// 
// Use this file to import your target's public headers that you would like to expose to Swift. 
// 

#import "Actions.h" 

...

// 
// main.swift 
// test 
// 


import Foundation 

let a = ActionObject() 
a.action = { 
    print("swift a action") 
} 
let b = ActionObject() 
b.action = { 
    print("swift b action") 
} 
let arr: NSArray = [a,b] 

let actions = ActionContainer() 
actions.actions = arr as [AnyObject] 
actions.job() 

農產品

swift a action 
swift b action 
Program ended with exit code: 0 

...

@implementation ActionContainer 
-(void)job { 
    if (_actions != nil) { 
     NSUInteger count = _actions.count; 
     NSUInteger i; 
     for (i = 0; i < count; i++) { 
      ActionObject *action = _actions[i]; 
      // myAction is 'unboxed' swift block 
      // you can save it, run it 
      // somwhere in you ObjectiveC code 
      dispatch_block_t myAction = action.action; 
      // run it 
      myAction(); 
     } 

    } 
}