ios - 复制自定义数组而不指向 iOS ARC 中的旧数组

Question

我想知道如何在不指向旧数组的情况下深度复制自定义数组。我检查了几乎所有堆栈溢出问题，但没有找到任何解决方案。请帮助复制数组而不指向旧数组，这样我的新数组操作(添加、删除)不会影响原始/旧数组。

这是我的主要数组声明。

@property (nonatomic, strong) NSArray *secArray;

将自定义对象添加到数组

      NSMutableArray *secDataArray = [NSMutableArray array];
     [SetRequest.SetMembers enumerateObjectsUsingBlock:^(SetMember *member, NSUInteger idx, BOOL *stop) {

        SecData *secData = [secDataArray lastObject];
        if(!secData || ![secData.secTitle isEqualToString:member.setHeader])
        {
          secData = [secData secDataWithTitle:member.setHeader
                                                     lines:@[member]];
          secData.open = YES;
          [secDataArray addObject:secData];
        }
        else
        {
          [secData.lines addObject:member];
        }
    }];

        self.secArray = [secDataArray copy];// copy secDatarray to my main array(secArray)

自定义数组的深度复制到新数组

 NSArray *newSecarray=[[NSMutableArray alloc] initWithArray:secArray copyItems:YES];

但是从新数组中删除数据也会从旧数组中删除数据。

SecData *dataoldarraydata = [self.secArray objectAtIndex:0];
SecData *datnewarraydata = [newSecarray objectAtIndex:0];

[datnewarraydata.rows removeLastObject];

NSLog (@"oldarraydata=%d",[secArray.lines count]); //Out Put = 33 (It should be 34 for as i don't want delete data from original array)
NSLog (@"newarraydata=%d",[newSecarray.lines count]); //Out Put = 33

//这是我的自定义 secData 类。

//secData.h 文件

@interface secData : NSObject

@property (nonatomic, strong) NSMutableArray *lines;
@property (nonatomic, strong) NSString *secTitle;
@property (nonatomic, strong) NSString *secIndexTitle;
@property (nonatomic, assign) BOOL open;

+ (id) secDataWithTitle:(NSString*)inTitle lines:(NSArray*)inLines;
+ (id) secDataWithLines:(NSArray*)inLines;
+ (id)copy;

@end

//secData.m 文件

#import "SecData.h"

@implementation SecData

@synthesize lines;

 + (id) secWithLines:(NSArray*)inLines 
 {
return [self secDataWithTitle:nil lines:inlines];
 }

+ (id) secDataWithTitle:(NSString*)inTitle Lines:(NSArray*)inLines
{
    SecData *sec = (SecData *)[[self alloc] init];
    [sec setSecTitle:inTitle];

    NSMutableArray *mutableCopyArray = [[NSMutableArray alloc] initWithArray:inLines];
    [sec setLines:mutableCopyArray];

    return sec;
}

- (NSMutableArray*)lines
{
    if(! lines)
    {
        self. lines = [NSMutableArray array];
    }
    return lines;
}

- (void) setLines:(NSMutableArray *)aArray
{
    NSMutableArray *newArray = aArray;

    if(![aArray isKindOfClass:[NSMutableArray class]])
        newArray = [NSMutableArray arrayWithArray:aArray];

    lines = newArray;
}

- (id)copyWithZone: (NSZone *)zone
{
    id  seccopy = [[[self class] alloc]init];
    if(seccopy ) {

        NSMutableArray *temp = [[NSMutableArray alloc]initWithArray:self.lines copyItems:YES];

        [seccopy setSecTitle:self.secTitle];
        [seccopy setLines:self.lines];
    }


    return seccopy;
}

@end

Answer 1

如果您需要真正的深拷贝，那么还有一种方法可以存档然后取消存档集合。您将需要实现 NSCoding要归档/取消归档的类中的协议(protocol)。这不是一种有效的方法，但它确实提供了真正的深拷贝，即您的数组将完全不同。

使用此代码进行复制:

NSArray* newSecArray = [NSKeyedUnarchiver unarchiveObjectWithData:
          [NSKeyedArchiver archivedDataWithRootObject:secArray]];

也可以看 Apple Docs关于浅拷贝和深拷贝。 Apple 还在其文档中说明了这种用于真正深度复制的方法。

这是 Archives and Serializations Programming Guide 的链接关于编码/解码对象。