objective-c - 向 NSMutablearray 添加数据时出现 EXC_BAD_ACCESS

Question

好吧，我正在解析来自 json 的数据，并将它们动态添加到数组中。如果我添加其中的 12 个数据，就可以了。但是当我要添加第 13 个时，我得到这个错误(不管第 13 个是什么):

EXC_BAD_ACCESS

这是我的代码:

HomeView.h

#import <UIKit/UIKit.h>

@interface HomeView : UIViewController{  
    NSMutableData *responseData;
}

@property (nonatomic, strong) NSMutableData *responseData;

@end

和我的实现文件:

@implementation HomeView
@synthesize responseData;

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(@"connectionDidFinishLoading");
NSLog(@"Succeeded! Received %d bytes of data",[self.responseData length]);

// convert to JSON
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:self.responseData options:NSJSONReadingMutableLeaves error:&myError];
    NSString *parsed_track=[res objectForKey:@"data1"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data2"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data3"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data4"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data5"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data6"];
    [tracks_condition addObject:parsed_track];

   parsed_track=[res objectForKey:@"data7"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data8"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data9"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data10"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data11"];
    [tracks_condition addObject:parsed_track];
    parsed_track=[res objectForKey:@"data12"];
    [tracks_condition addObject:parsed_track];

  // parsed_track=[res objectForKey:@"data13"]; //HERE COMES THE ERROR
   // [tracks_condition addObject:parsed_track];

我想这与内存管理有关，但我找不到。

Answer 1

Are you sure there is an object for key @"data13" 也许这个键不存在并返回nil。在这种情况下，您需要检查 nil 并决定是否添加它。如果您想添加它，只需添加 [NSNull null] 即可，因为您必须使用继承 NSObject 的对象。

编辑:请也尝试在 for 循环中使用它并使用 [NSString stringWithFormat.....]

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