复制自定义对象
我有一个叫做Layer的对象,它有一些属性和一些方法。
我需要将Layer传递给第二个视图控制器:
SecondVC *view = [self.storyboard instantiateViewControllerWithIdentifier:@"2VC"]; view.Layer = [[Layer alloc] initWithMapLayer:self.Layer]; view.delegate = self; UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:view]; navController.modalTransitionStyle = UIModalTransitionStyleCoverVertical; [self presentModalViewController:navController animated:YES];
在SecondVC中,我可以改变属性。 然后我通过委托返回Layer对象;
-(void)done { [self.delegate returnLayer:self.layer]; [self dismissModalViewControllerAnimated:YES]; }
现在我的问题是,我传递了一个指针,我的第一个视图控制器的图层对象,当我更新第二个视图控制器中的图层,我的第一个视图控制器的图层对象也正在更新。
因此,我不知道它是否已经改变(如果有的话,我需要运行一些代码)。
我怎样才能创build我的图层对象的副本,并通过,而不是我的第一个视图控制器的图层对象的指针?
编辑:
我曾尝试使用第二个init方法:
-(id)initWithLayer:(Layer *)Layer { if (self = [super init]) { self.call = [[FunctionCall alloc] init]; self.HUD = [[MBProgressHUD alloc] init]; self.Layers = [[NSMutableDictionary dictionaryWithDictionary:Layer.Layers] copy]; self.nameList = [[NSArray arrayWithArray:Layer.nameList] copy]; } return self; }
哪个没有解决。
EDIT2:
试着
Layer *copyLayer = [self.myLayer copy]; layerView.myLayer = copyLayer;
并得到错误
-[layer copyWithZone:]: unrecognized selector sent to instance 0xfc72c40 2012-06-12 11:15:28.584 Landscout[8866:1fb07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Layer copyWithZone:]: unrecognized selector sent to instance 0xfc72c40'
解决了:
我向initWithLayer方法添加了一个深层的副本:
for (id key in layer.layers) { [newLayers setValue:[[layer.layers objectForKey:key] mutableCopy] forKey:[key mutableCopy]]; } for (id name in layer.nameList) { [newList addObject:[name mutableCopy]]; }
这给了我一个Layer对象的副本
您将需要实现copy
function到您的对象
在你的Layer.m
- (id)copy { Layer *layerCopy = [[Layer alloc] init]; //YOu may need to copy these values too, this is a shallow copy //If YourValues and someOtherValue are only primitives then this would be ok //If they are objects you will need to implement copy to these objects too layerCopy.YourValues = self.YourValues; layerCopy.someOtherValue = self.someOtherValue; return layerCopy; }
现在在你的调用函数中
//instead of passing self.Layer pass [self.Layer copy] view.Layer = [[Layer alloc] initWithMapLayer:[self.Layer copy]];