通过一个NSDictionary iterrating与子对象

我有需要一个NSDictionary的方法：通过一个NSDictionary iterrating与子对象

-(id)initWithJSONDictionary:(NSDictionary *)dataDictionary{ 
    self = [super init]; 
    NSLog(@"********************************* %@ ",dataDictionary); 
    for(NSString * key in dataDictionary){ 
     if([key isEqualToString:@"filters"]){ 
      NSDictionary * filtersSubDict = [dataDictionary objectForKey:key]; 
      for(NSString *sfKey in filtersSubDict){ 
       NSLog(@"new filter: %@", sfKey);    
       NSDictionary *filterObject = [filtersSubDict objectForKey:sfKey]; 
       // this line is throwing some kind of thread exception 
      } 
      } 
     } 
     return self; 
}

任何线索，为什么与评论下它抛出一个异常行： **第一掷调用堆栈：

(0x1d04012 0x1141e7e 0x1d8f4bd 0x1cf3bbc 0x1cf394e 0x1052b 0x137fe 0x259b3 0x4a6853f 0x4a7a014 0x4a6a7d5 0x1caaaf5 0x1ca9f44 0x1ca9e1b 0x1c5e7e3 0x1c5e668 0x85ffc 0x27fd 0x2725) 
libc++abi.dylib: terminate called throwing an exception 
(lldb)

第一NSLog的显示整个的NSDictionary示出了该：

{ 
    errorCode = 0; 
    filters =  (
       { 
      id = 1001; 
      name = "Base Lenses"; 
      sequence = 1; 
     }, 
       { 
      id = 1002; 
      name = "Standard Anti-Reflective"; 
      sequence = 2; 
     }, 
       { 
      id = 1003; 
      name = "Premium Anti-Reflective"; 
      sequence = 3; 
     }, 
       { 
      id = 1004; 
      name = "Enhanced Scratch Resistance"; 
      sequence = 4; 
     }, 
       { 
      id = 1005; 
      name = Sun; 
      sequence = 5; 
     }, 
       { 
      id = 1006; 
      name = Tint; 
      sequence = 6; 
     }, 
       { 
      id = 1007; 
      name = "Clear To Dark"; 
      sequence = 7; 
     } 
    ); 
    lenses =  { 
     Glass =   (
         { 
       fsv = 1; 
       inStore = 1; 
       lom = 0; 
       price = 465; 
       style = "Glass Std AR"; 
       styleFilters =     (
        1002 
       ); 
       type = "Single Vision"; 
       visionCorrection = singleVision; 
      }, 
         { 
       fsv = 1; 
       inStore = 0; 
       lom = 1; 
       price = 395; 
       style = "Prem Plastic Std AR"; 
       styleFilters =     (
        1002 
       ); 
       type = "SV HD"; 
       visionCorrection = singleVision; 
      } 
     ); 
     "Plastic/Hi-index" =   (
         { 
       fsv = 1; 
       inStore = 1; 
       lom = 0; 
       price = 395; 
       style = "Prem Plastic Std AR"; 
       styleFilters =     (
        1002, 
        1006 
       ); 
       type = "SV HD"; 
       visionCorrection = singleVision; 
      }, 
         { 
       fsv = 1; 
       inStore = 0; 
       lom = 1; 
       price = 465; 
       style = "Glass Std AR"; 
       styleFilters =     (
        1002, 
        1006 
       ); 
       type = "SV HD"; 
       visionCorrection = singleVision; 
      } 
     ); 
     Polycarbonate =   (
         { 
       fsv = 1; 
       inStore = 1; 
       lom = 0; 
       price = 395; 
       style = "FeatherWates Classic"; 
       styleFilters =     (
        1001 
       ); 
       type = "SV Wrap"; 
       visionCorrection = singleVision; 
      }, 
         { 
       fsv = 1; 
       inStore = 0; 
       lom = 1; 
       price = 495; 
       style = "FeatherWates Classic"; 
       styleFilters =     (
        1001 
       ); 
       type = "SV Wrap"; 
       visionCorrection = singleVision; 
      } 
     ); 
    }; 
    materials =  (
     Polycarbonate, 
     "Plastic/Hi-index", 
     Glass 
    ); 
}

我正在尝试为“过滤器”中的每个节点创建一个新对象，以获取id，名称和序列值

来源

2013-04-09 erik

该调用堆栈没有帮助：/请用符号表示它。 – 2013-04-09 17:53:59

尝试进入断点选项卡并打开所有例外的断点。当它抛出你看到的异常时，这将打破调试器。 – thegrinner 2013-04-09 17:54:43

格式化后请查看您的代码。我不应该得到+10吗？ – 2013-04-09 18:01:28

没有看到您的NSLog声明在说什么或知道您的异常实际上是什么，在你的代码可能抛出异常：

for(NSString *key in dataDictionary) {

此行可能如果dataDictionary实际上不是一个NSDictionary扔，但被其他一些非<NSFastEnumeration> JSON对象，像一个NSString，NSNumber等

if([key isEqualToString:@"filters"]){

此行可能会引发如果key并不是真正的NSString，因此没有实现方法-isEqualToString:。

 NSDictionary *filtersSubDict = [dataDictionary objectForKey:key];

如果dataDictionary是一个快速枚举JSON对象，但并不是真正的NSDictionary这条线可以抛出。（换句话说，它可能是NSArray，这一行会抛出一个“无法识别选择器”objectForKey：“异常）。

 for (NSString *sfKey in filtersSubDict) {

和上面一样，这可能抛出，如果filtersSubDict不是NSArray或NSDictionary。

  NSLog(@"new filter: %@", sfKey); 
      NSDictionary *filterObject = [filtersSubDict objectForKey:sfKey];

这可能抛出，如果filtersSubDict不是NSDictionary而是代替NSArray（同上）。

 } 
    } 
}

所以，如果它抛出的filterObject = ...线，然后有机会，filtersSubDict实际上不是一个字典，你得到一个无法识别的选择例外。

来源

2013-04-09 18:04:48

我喜欢upvoter，他在15秒内阅读完整的答案！ – 2013-04-09 18:07:01

通过一个NSDictionary iterrating与子对象

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