ios - 为什么返回函数会发出SIGABRT信号？

Question

我对 objective-c 不熟悉。
我不明白为什么我的函数无法正常工作，它会在函数返回时导致SIGBART错误。

+ (NSArray*) jsonToArray:(NSString*)jsonString
{
    id mappedObj = nil;
    RKObjectMappingProvider* mapProv = [[RKObjectMappingProvider alloc] init];

    RKObjectMapping* answerMapping = [SMAnswersWrapper entityMappingForSerializer];
    answerMapping.objectClass = [NSMutableDictionary class];

    [mapProv setSerializationMapping:answerMapping forClass:[SMAnswersWrapper class]];
    RKObjectMapping *proofsEntityMapping = [SMEntityArrayWrapper entityMappingWithContentMapping:answerMapping];

    [mapProv setMapping:proofsEntityMapping forKeyPath:@""];

    if (jsonString)
    {
        id obj = [jsonString objectFromJSONString];
        if (obj)
        {
            RKObjectMapper* mapper = [[RKObjectMapper alloc] initWithObject:obj mappingProvider:mapProv];

            RKObjectMappingResult* res = [mapper performMapping];
            mappedObj = [res asCollection];

            [mapper release];
        }
    }
    [mapProv release];
    return [[[mappedObj content] retain] autorelease];
}

错误位置在此行:

return [[[mappedObj content] retain] autorelease];

谢谢。

编辑

我发现我的错误，我无法访问我必须强制转换mapdObj的 [[[mappedObj content] retain] autorelease];的内容。

Answer 1

尝试以下操作:

+ (NSArray*) jsonToArray:(NSString*)jsonString
{
    id mappedObj = nil;
    RKObjectMappingProvider* mapProv = [[RKObjectMappingProvider alloc] init];

    RKObjectMapping* answerMapping = [SMAnswersWrapper entityMappingForSerializer];
    answerMapping.objectClass = [NSMutableDictionary class];

    [mapProv setSerializationMapping:answerMapping forClass:[SMAnswersWrapper class]];
    RKObjectMapping *proofsEntityMapping = [SMEntityArrayWrapper entityMappingWithContentMapping:answerMapping];

    [mapProv setMapping:proofsEntityMapping forKeyPath:@""];

    if (jsonString)
    {
        id obj = [jsonString objectFromJSONString];
        if (obj)
        {
            RKObjectMapper* mapper = [[RKObjectMapper alloc] initWithObject:obj mappingProvider:mapProv];

            RKObjectMappingResult* res = [mapper performMapping];
            mappedObj = [res asCollection];

            [mapper release];
        }
    }
    [mapProv release];
    if (mappedObj)
    {
        return [[[mappedObj content] retain] autorelease];
    }
    return [NSArray array];

}

在您的代码中，如果 jsonString或 obj为nil，则不会初始化mappingObj。这种情况可能会导致访问 [mappedObj content]时崩溃。

试试这个，对您有帮助。