Ios 通过从属性列表读取的NSDictionary进行循环会带来麻烦

嘿，伙计们，我在读这样一篇文章：

如您所见，它是一个plist，包含不同类型的注释信息（C，Visitor）。我可以很好地显示每个注释类型，但我正在尝试循环所有类型，并在地图视图上同时显示所有注释。代码如下：

NSLog(@"loadAnnotations");
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"PermitData" ofType:@"plist"];
NSDictionary *rootOfPermitDataPlistDict = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
// NSMutableDictionary *permitDict = [[NSMutableDictionary alloc] init];
 if ([self title] == @"All Permits") {
  for (id key in rootOfPermitDataPlistDict) {
   NSLog(@"key:%@",key);

   //[key retain];
   NSMutableDictionary *permitDict = [NSDictionary dictionaryWithDictionary:[rootOfPermitDataPlistDict objectForKey:key]];
   //[key release];

   //array containing annotation information: latitude, longitude, title, subtitle(see PermitData.plist)
   NSArray *annotationsArray = [[NSArray alloc] initWithArray:[permitDict objectForKey:@"annotations"]];
   [permitDict release];
   [rootOfPermitDataPlistDict release];

   CLLocationCoordinate2D workingCoordinate;
   NSDictionary *annotationContainerDict = [[NSDictionary alloc] init];
   //loop through annotations array, creating parking annotations filled with the information found in the plist
   for(annotationContainerDict in annotationsArray){
    NSLog(@"%@",annotationContainerDict);

    ParkingAnnotation *parkingAnnot = [[ParkingAnnotation alloc] init];
    workingCoordinate.latitude = [[annotationContainerDict objectForKey:@"latitude"] doubleValue];
    workingCoordinate.longitude = [[annotationContainerDict objectForKey:@"longitude"] doubleValue];
    [parkingAnnot setCoordinate:workingCoordinate];
    [parkingAnnot setTitle:[annotationContainerDict objectForKey:@"title"]];
    [parkingAnnot setSubtitle:[annotationContainerDict objectForKey:@"subtitle"]];
    if ([parkingAnnot title] == @"C Parking") [parkingAnnot setAnnotationType:annotationTypeC];
    else if ([parkingAnnot title] == @"Visitor Parking") [parkingAnnot setAnnotationType:annotationTypeVisitor];
    [mapView addAnnotation:parkingAnnot];
    [parkingAnnot release];
   }
   [permitDict release];
  }
 }

这是我运行程序时的控制台输出：

2010-11-25 03:25:28.020 Parking[38918:207] All Permits
2010-11-25 03:25:28.021 Parking[38918:207] loadAnnotations
2010-11-25 03:25:28.021 Parking[38918:207] key:C
2010-11-25 03:25:28.021 Parking[38918:207] {
    latitude = "38.545301";
    longitude = "-121.754066";
    subtitle = "VP 17";
    title = "C Parking";
}
2010-11-25 03:25:28.022 Parking[38918:207] {
    latitude = "38.544831";
    longitude = "-121.754785";
    subtitle = "VP 16";
    title = "C Parking";
}
2010-11-25 03:25:28.022 Parking[38918:207] {
    latitude = "38.544781";
    longitude = "-121.755729";
    subtitle = "VP 22";
    title = "C Parking";
}
2010-11-25 03:25:28.022 Parking[38918:207] {
    latitude = "38.544412";
    longitude = "-121.752489";
    subtitle = "VP 15";
    title = "C Parking";
}

因此，它正确地循环第一个NSDictionary，但在即将开始循环下一个NSDictionary时崩溃。我尝试将NSDictionary更改为NSMutableDictionary，但结果是一样的。因此，当我在表视图中选择“allallows”行时，它会挂起几分之一秒（不切换到map视图），然后崩溃，不会产生错误

如果有人不介意在这里帮助我，我将不胜感激。提前谢谢

编辑： 以下是堆栈跟踪（在下面的注释中描述）：

2010-11-25 20:28:08.141停车许可证
2010-11-25 20:28:08.142停车场[39400:207]负荷注释
2010-11-25 20:28:08.142停车键：C
2010-11-25 20:28:08.143停车场[39400:207]{
纬度=“38.545301”；
经度=“-121.754066”；
副标题=“VP 17”；
title=“C停车场”；
}
2010-11-25 20:28:08.143停车场[39400:207]{
纬度=“38.544831”；
经度=“-121.754785”；
副标题=“VP 16”；
title=“C停车场”；
}
2010-11-25 20:28:08.143停车场[39400:207]{
纬度=“38.544781”；
经度=“-121.755729”；
副标题=“VP 22”；
title=“C停车场”；
}
2010-11-25 20:28:08.144停车场[39400:207]{
纬度=“38.544412”；
经度=“-121.752489”；
副标题=“VP 15”；
title=“C停车场”；
}
2010-11-25 20:28:08.145停止[39400:207]***由于未捕获的异常“NSGenericeException”而终止应用程序，原因：“***集合在枚举时发生了变异。{type=mutable dict，count=1，
条目=>
0 :  = 
}
'
***第一次抛出时调用堆栈：
(
0 CoreFoundation 0x025fdb99例外预处理+185
1 libobjc.A.dylib 0x0274d40e objc_异常_抛出+47
2 CoreFoundation 0x025fd659 uunsuFastEnumerationMutationHandler+377
3停车0x00002e93-[ParkingMapViewController加载注释]+364
4停车0x00002caf-[ParkingMapViewController viewDidLoad]+117
5 UIKit 0x0036a5ca-[UIViewController视图]+179
6 UIKit 0x003689f4-[UIViewController contentScrollView]+42
7 UIKit 0x003787e2-[UINavigationController _计算机和应用程序克隆内容插入DeltaForviewController:+48
8 UIKit 0x00376ea3-[UINavigationController\u layoutViewController:+43
9 UIKit 0x00378067-[UINavigationController\u开始转换：从ViewController:toViewController:+326
10 UIKit 0x00372ccd-[UINavigationController _STARTDEFERREEDTRANSION（如果需要）]+266
11 UIKit 0x00379d8b-[UINavigationController推送视图控制器：转换：强制立即:+876
12 UIKit 0x00372b67-[UINavigationController推送视图控制器：动画：:+62
13停车0x00002914-[PermitListViewController表视图：didSelectRowAtIndexPath:+307
14 UIKit 0x00333a48-[UITableView\u selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:+1140
15 UIKit 0x0032a32e-[UITableView\u用户选择行索引路径：+219
16基金会0x000 03F21A
17 CoreFoundation 0x025def73\uuuu CFRUNLOOP\u正在调用\u OUT\u到\u计时器\u回调函数\uuuu+19
18芯基础0x025e05b4 uu CFRunLoopDoTimer+1364
19 CoreFoundation 0x0253cdd9_u CFRunLoopRun+1817
20 CoreFoundation 0x0253c350 CFRUNLOOPSCRONE+208
21 CoreFoundation 0x0253c271 CFRUNLOOPSRUNINMODE+97
22图形服务0x02edc00c GSEventRunModal+217
23图形服务0x02edc0d1 GSEventRun+115
24 UIKit 0x002ceaf2 UIApplicationMain+1160
25停车位0x00001e08主+102
26停车0x00001d99启动+53
)
在抛出“NSException”实例后调用terminate

---

但是，我正在for循环中释放permitdct（第二个[permitdct release]没有注释），所以我不知道为什么它会抱怨NSDictionary是不可变的。如您所见，PermitDisct的类型为NSMutableDictionary，因此我不知道它为什么会给我这个错误。

代码崩溃有两个主要原因

首先，该行位于for循环内：

[rootOfPermitDataPlistDict release];

销毁当前正在循环的对象。将其移到最末端--

if（[self title]…

语句的右括号之后

第二行，这两行表示：

[permitDict release];

应删除。不要释放PermitDisct，因为您正在使用dictionaryWithDictionary创建它，该dictionaryWithDictionary返回自动删除的对象

有了这两个更改，代码应该可以运行了。

---

然而还有一些其他问题：

• 您可以alloc+init

  annotationsArray

  但从不释放它（内存泄漏）。在通过该数组的for循环之后释放它（您当前有第二个

  [permitDict release]；

  ）
• 你可以使用alloc+init

  [permitDict release];
  

  NSString * const PPAnnotationsKey   = @"annotations";
  NSString * const PPTitleKey         = @"title";
  NSString * const PPSubtitleKey      = @"subtitle";
  NSString * const PPLatitudeKey      = @"latitude";
  NSString * const PPLongitudeKey     = @"longitude";
  
  NSLog(@"loadAnnotations");
  NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"PermitData" ofType:@"plist"]; // autoreleased
  NSDictionary *permitDictionary = [NSDictionary dictionaryWithContentsOfFile:plistPath]; // autoreleased
  if ([[self title] isEqualToString:@"All Permits"]) {
      for (NSString *parkingGroup in permitDictionary) {
          NSLog(@"parkingGroup == %@", parkingGroup);
          NSArray *annotations = [parkingGroup objectForKey:PPAnnotationsKey];
          for (NSDictionary *entry in annotations) {
              PPParkingAnnotation *annotation = [PPParkingAnnotation parkingAnnotationWithDictionary:entry]; // autoreleased
              if (annotation) {
              // assuming here that mapView's addAnnotation: will retain the
              // annotation
              [mapView addAnnotation:annotation]; 
              }
          }
      }
  }
  
  @interface PPParkingAnnotation : NSObject <MKAnnotation> {
      CLLocationCoordinate2D   coordinate;
      NSString                *title;
      NSString                *subtitle;
  }
  + (id)parkingAnnotationWithDictionary:(NSDictionary *)dictionary;
  - (id)initWithDictionary:(NSDictionary *)dictionary;
  
  @properties...
  @end
  
  @implementation PPParkingAnnotation
  
  + (id)parkingAnnotationWithDictionary:(NSDictionary *)dictionary {
      return [[[[self class] alloc] initWithDictionary:dictionary] autorelease];
  }
  
  - (id)initWithDictionary:(NSDictionary *)dictionary {
      [self setTitle:[dictionary objectForKey:PPTitleKey]];
      [self setSubtitle:[dictionary objectForKey:PPTitleKey]];
      // and so on.
  }