将数组中的数据从一个类传递到另一个类

hoping for advice on something.

希望得到一些建议。

I have a Levels Engine class that creates an NSMutable Array called levelsArray.

我有一个Levels Engine类,它创建一个名为levelsArray的NSMutable Array。

I am passing the data to a Levels View Controller which is working just fine.

我正在将数据传递给Levels View Controller,它正常工作。

I also have a Particle Emitter class to which I am hoping to pass the level data.

我还有一个粒子发射器类,我希望传递水平数据。

However I am constantly being told that the count level of the array is 0 when I pass it to the Particle Emitter class.

然而,当我将它传递给粒子发射器类时,我不断被告知数组的计数级别为0。

The array has been setup properly:

数组已正确设置:

    **LevelsEngine.h**  
    @interface
    LevelsEngine : NSObject {   
    NSMutableArray *levelsArray;         }

    @property (retain) NSMutableArray
    *levelsArray;  




    **LevelsEngine.m**  
    @synthesize levelsArray;  
    LevelsArray =[NSMutableArray array];


    **Code used in ParticleEmitter.m**   
    newlevelsArray = [NSMutableArray array];  
    newlevelsArray=view.levelsArray;

Am I right in thinking I am having this error because I am trying to pass the array data from one NSObject to another and not to a view controller?If so how can I pass the data?

我是否正确地认为我有这个错误,因为我试图将数组数据从一个NSObject传递到另一个NSObject而不是视图控制器?如果是这样我怎样才能传递数据?

2 个解决方案

#1

Couple of things.

几件事。

    **Code used in ParticleEmitter.m**   
    newlevelsArray = [NSMutableArray array];  
    newlevelsArray=view.levelsArray;

The first line is creating a new array. The 2nd line is assigning newlevelsArray to be a pointer to the array in view.levelsArray, leaving the object you created in line #1 orphaned.

第一行是创建一个新数组。第二行是将newlevelsArray指定为view.levelsArray中指向数组的指针,使您在第1行中创建的对象保持孤立状态。

I think you were intending the 2nd line to be a field by field copy of the array, but assignments of objects don't work that way.

我认为你打算将第二行作为数组的字段副本,但是对象的赋值不会那样。

You can fix this by 2 things.

你可以通过两件事来解决这个问题。

1) Remove the first line newlevelsArray = [NSMutableArray array];

1)删除第一行newlevelsArray = [NSMutableArray array];

2) Change the 2nd line to `newlevelsArray = [view.levelsArray copy];

2)将第二行更改为`newlevelsArray = [view.levelsArray copy];

This will actually do a copy, which is probably what you want since you can then go ahead and modify newlevelsArray in ParticleEmitter.m without changing the value in view.

这实际上会做一个副本,这可能是你想要的,因为你可以继续修改ParticleEmitter.m中的newlevelsArray而不改变视图中的值。

Important note: don't forget to create a -dealloc: method in your Particle emitter class which releases newlevelsArray:

重要说明:不要忘记在Particle发射器类中创建一个-dealloc:方法,该类释放newlevelsArray:

-(void)dealloc {
   if (newlevelsArray) [newlevelsArray release];
   [super dealloc];
}

An alternative solution is to use setters.

另一种解决方案是使用setter。

Instead of:

2) Change the 2nd line to newlevelsArray = [view.levelsArray copy];

2)将第二行更改为newlevelsArray = [view.levelsArray copy];

Do:

2) Change the 2nd line to this.newlevelsArray = view.levelsArray; Where you have to define newlevelsArray to be a property of the ParticleEmitter class using

2)将第二行更改为this.newlevelsArray = view.levelsArray;您必须将newlevelsArray定义为使用的ParticleEmitter类的属性

@property (copy) NSMutableArray * newlevelsArray;

@property(copy)NSMutableArray * newlevelsArray;

Note the use of "copy" instead of "retain". This will do a field by field copy of the array, which is most likely advisable for containers of mutable objects.

注意使用“复制”而不是“保留”。这将执行数组的字段副本,这很可能适用于可变对象的容器。

#2

You need to change your code,

你需要改变你的代码,

call the newlevelarray in the LevelsEngine.h calls.

在LevelsEngine.h调用中调用newlevelarray。

and your code should look like

你的代码应该是这样的

Classobject.newlevelsArray =[nsarray arraywitharray: LevlesArray] ;

Classobject.newlevelsArray = [nsarray arraywitharray:LevlesArray];

This should solve your problem.

这应该可以解决您的问题。

#1