问题描述
我已经阅读了 NSCopying 文档，但我仍然不确定如何实现所需的内容。
我的班级供应商：
@interface供应商：NSObject
{
NSString * vendorID;
NSMutableArray * availableCars;
BOOL atAirport;
}
@property（非原子，复制）NSString * vendorID;
@property（nonatomic，retain）NSMutableArray * availableCars;
@property（nonatomic，assign）BOOL atAirport;
- （id）initFromVehVendorAvailsDictionary：（NSDictionary *）vehVendorAvails;
@end
供应商 class有一个名为 Car 的对象数组。
我的汽车对象：
@interface Car：NSObject
{
BOOL isAvailable;
NSString * transmissionType;
NSMutableArray * vehicleCharges;
NSMutableArray *费用;
}
@property（非原子，分配）BOOL isAvailable;
@property（非原子，复制）NSString * transmissionType;
@property（nonatomic，retain）NSMutableArray * vehicleCharges;
@property（非原子，保留）NSMutableArray *费用;
- （id）initFromVehicleDictionary：（NSDictionary *）vehicleDictionary;
@end
所以，供应商包含一个 Car 对象的数组。 Car 包含2个其他自定义对象数组。
供应商和 Car 都是字典中的init 。我将添加其中一种方法，它们可能相关也可能不相关。
- （id）initFromVehVendorAvailsDictionary：（NSDictionary * ）vehVendorAvails {
self.vendorCode = [[vehVendorAvails objectForKey：@Vendor]
objectForKey：@@ Code];
self.vendorName = [[vehVendorAvails objectForKey：@Vendor]
objectForKey：@@ CompanyShortName];
self.vendorDivision = [[vehVendorAvails objectForKey：@Vendor]
objectForKey：@@ Division];
self.locationCode = [[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@@ Code];
self.atAirport = [[[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@@AtAirport] boolValue];
self.venLocationName = [[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@@ Name];
self.venAddress = [[[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@Address]
objectForKey：@ AddressLine];
self.venCountryCode = [[[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@Address]
objectForKey：@CountryName]
objectForKey：@@ Code];
self.venPhone = [[[[vehVendorAvails objectForKey：@Info]
objectForKey：@LocationDetails]
objectForKey：@Telephone]
objectForKey：@ @ ******中国];
availableCars = [[NSMutableArray alloc] init];
NSMutableArray * cars =（NSMutableArray *）[vehVendorAvails objectForKey：@VehAvails];
for（int i = 0; i< [cars count]; i ++）{
Car * car = [[Car alloc] initFromVehicleDictionary：[cars objectAtIndex：i ]];
[availableCars addObject：car];
[汽车发布];
}
self.venLogo = [[[vehVendorAvails objectForKey：@Info]
objectForKey：@TPA_Extensions]
objectForKey：@VendorPictureURL] ;
返回自我;
}
总结一下这个可怕的问题。
我需要复制一个 Vendor 对象的数组。我相信我需要在供应商上实现 NSCopying 协议，这可能意味着我还需要在<$上实现它c $ c> Car ，因为供应商包含 Car 的数组。这意味着我还需要在属于 Car 对象的2个数组中保存的类上实现它。
供应商上实施
NSCopying 协议，我真的很感激，我可以'在任何地方找到任何教程。实施，你的对象必须响应 -copyWithZone： 选择器。以下是您声明符合它的方式：
@interface MyObject：NSObject< NSCopying> {
然后，在你对象的实现中（你的 .m 文件）：
- （id）copyWithZone：（NSZone *）zone
{
//在这里复制代码
}
您的代码应该怎么做？首先，创建一个对象的新实例 - 你可以调用 [[[self class] alloc] init] 来获取当前类的初始化obejct，这对于子类。然后，对于支持复制的 NSObject 的子类的任何实例变量，可以调用 [thatObject copyWithZone：zone] 为新对象。对于原始类型（ int ， char ， BOOL 和朋友）只是将变量设置为相等。因此，对于您的obejct供应商，它看起来像这样：
- （id）copyWithZone：（NSZone *）zone
{
id copy = [[[self class] alloc] init];
if（copy）{
//复制NSObject子类
[copy setVendorID：[[self.vendorID copyWithZone：zone] autorelease]];
[copy setAvailableCars：[[self.availableCars copyWithZone：zone] autorelease]];
//设置原语
[copy setAtAirport：self.atAirport];
}
返回副本;
}
I've read the NSCopying docs but I am still very unsure about how to implement what is required.
My class Vendor:
@interface Vendor : NSObject
{
NSString *vendorID;
NSMutableArray *availableCars;
BOOL atAirport;
}
@property (nonatomic, copy) NSString *vendorID;
@property (nonatomic, retain) NSMutableArray *availableCars;
@property (nonatomic, assign) BOOL atAirport;
- (id)initFromVehVendorAvailsDictionary:(NSDictionary *)vehVendorAvails;
@end
The Vendor class has an array of objects called Car.
My Car object:
@interface Car : NSObject
{
BOOL isAvailable;
NSString *transmissionType;
NSMutableArray *vehicleCharges;
NSMutableArray *fees;
}
@property (nonatomic, assign) BOOL isAvailable;
@property (nonatomic, copy) NSString *transmissionType;
@property (nonatomic, retain) NSMutableArray *vehicleCharges;
@property (nonatomic, retain) NSMutableArray *fees;
- (id) initFromVehicleDictionary:(NSDictionary *)vehicleDictionary;
@end
So, Vendor holds an array of Car objects. Car holds 2 arrays of other custom objects.
Both Vendor and Car are init from a dictionary. I'll add one of these methods, they may or may not be relevant.
-(id)initFromVehVendorAvailsDictionary:(NSDictionary *)vehVendorAvails {
self.vendorCode = [[vehVendorAvails objectForKey:@"Vendor"]
objectForKey:@"@Code"];
self.vendorName = [[vehVendorAvails objectForKey:@"Vendor"]
objectForKey:@"@CompanyShortName"];
self.vendorDivision = [[vehVendorAvails objectForKey:@"Vendor"]
objectForKey:@"@Division"];
self.locationCode = [[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"@Code"];
self.atAirport = [[[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"@AtAirport"] boolValue];
self.venLocationName = [[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"@Name"];
self.venAddress = [[[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"Address"]
objectForKey:@"AddressLine"];
self.venCountryCode = [[[[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"Address"]
objectForKey:@"CountryName"]
objectForKey:@"@Code"];
self.venPhone = [[[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"LocationDetails"]
objectForKey:@"Telephone"]
objectForKey:@"@PhoneNumber"];
availableCars = [[NSMutableArray alloc] init];
NSMutableArray *cars = (NSMutableArray *)[vehVendorAvails objectForKey:@"VehAvails"];
for (int i = 0; i < [cars count]; i++) {
Car *car = [[Car alloc] initFromVehicleDictionary:[cars objectAtIndex:i]];
[availableCars addObject:car];
[car release];
}
self.venLogo = [[[vehVendorAvails objectForKey:@"Info"]
objectForKey:@"TPA_Extensions"]
objectForKey:@"VendorPictureURL"];
return self;
}
So to summarize the scary problem.
I need to copy an array of Vendor objects. I believe I need to implement the NSCopying protocol on Vendor, which may mean I need to implement it also on Car since Vendor holds an array of Cars. That means I also need to implement it on the classes that are held in the 2 arrays belonging to the Car object.
I'd really appreciate it if I could get some guidance on implementing NSCopying protocol on Vendor, I can't find any tutorials on this anywhere.
To implement NSCopying, your object must respond to the -copyWithZone: selector. Here’s how you declare that you conform to it:
@interface MyObject : NSObject <NSCopying> {
Then, in your object’s implementation (your .m file):
- (id)copyWithZone:(NSZone *)zone
{
// Copying code here.
}
What should your code do? First, create a new instance of the object—you can call [[[self class] alloc] init] to get an initialized obejct of the current class, which works well for subclassing. Then, for any instance variables that are a subclass of NSObject that supports copying, you can call [thatObject copyWithZone:zone] for the new object. For primitive types (int, char, BOOL and friends) just set the variables to be equal. So, for your obejct Vendor, it’d look like this:
- (id)copyWithZone:(NSZone *)zone
{
id copy = [[[self class] alloc] init];
if (copy) {
// Copy NSObject subclasses
[copy setVendorID:[[self.vendorID copyWithZone:zone] autorelease]];
[copy setAvailableCars:[[self.availableCars copyWithZone:zone] autorelease]];
// Set primitives
[copy setAtAirport:self.atAirport];
}
return copy;
}
这篇关于实施NSCopying的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！