無法對象添加到NSMutableArray的

Question

嗨，我有一個類裏面的函數是的NSOperation的一個子類中運行此代碼：

//... 
@implementation DataLoader 

@synthesize addedAnnotations; 
@synthesize addedOverlays; 
@synthesize loaderFunc; 
@synthesize DLDelegate;  
//... 
-(id)initWithFunction:(LoaderFunc)func withDelegate:(id)delegate { 
    if (self = [super init]) { 
     self.addedOverlays = nil; 
     self.addedAnnotations = nil; 
     self.loaderFunc = func; 
     self.DLDelegate = delegate; 
     return self; 
    } 
    return nil; 
} 
//... 
//inside a function 
    for (ParkingAnnotations *annotation in fetchedObjects) { 
     ParkingAnnotation *parkingAnnot = [[ParkingAnnotation alloc] init]; 
     workingCoordinate.latitude = [[annotation latitude] doubleValue]; 
     workingCoordinate.longitude = [[annotation longitude] doubleValue]; 
     [parkingAnnot setCoordinate:workingCoordinate]; 
     [parkingAnnot setTitle:[annotation valueForKey:@"lotName"]]; 
     [parkingAnnot setAnnotationType:[annotation iconTypeRaw]]; 

     [self.addedAnnotations addObject:parkingAnnot];//parkingAnnot not added to array here 
     [parkingAnnot release]; 
    } 
//... 

添加註解是一個NSMutable陣列，我已經通過這個走代碼與調試器和由於某種原因parkingAnnot對象不會被添加到數組中。下面是類相關的頭代碼：

//...  
@interface DataLoader : NSOperation { 
     NSMutableArray *addedAnnotations; 
    NSMutableArray *addedOverlays; 
    LoaderFunc loaderfunc; 
    id <DataLoaderProtocol> DLDelegate; 
} 

@property (nonatomic, retain) NSMutableArray* addedAnnotations; 
@property (nonatomic, retain) NSMutableArray* addedOverlays; 
@property (nonatomic) LoaderFunc loaderFunc; 
@property (assign) id DLDelegate; 
//... 

這是因爲在我遇到問題的功能是從我的MapViewController複製一個驚人的問題，本質上是一樣的，但不是mapView addAnnotation:我加入改爲一個NSMutable數組。有什麼想法？提前致謝！

Answer 1

你究竟在哪裏實例化addedAnnotations數組？我只看到它在初始化函數中被賦值爲零，也許它應該變成類似於：

self.addedAnnotations = [[[NSMutableArray alloc] init] autorelease];