Question

我有这个代码，有时变量dConfiguration是Nil而且我得到一个EXC_BAD_ACCESS错误，并且大多数时候变量表示0个键/值对，并且错误几乎不可能重现，我只需单击我的按钮并且大部分时间都在工作，但在极少数情况下会失败。

serviceData = data;
dispatch_async(dispatch_get_main_queue(), ^{
    [loading removeFromSuperview];
    _tvTable.hidden = NO;
    dConfiguration =[NSJSONSerialization JSONObjectWithData:serviceData options:kNilOptions error:nil];
    if (![[dConfiguration objectForKey:@"NumberOfLines"] isEqual: [NSNull null]]) {
        _NumberOfLines = [[dConfiguration objectForKey:@"NumberOfLines"] integerValue];
    } else {
        _NumberOfLines = 1;
    }
    if(badget!=nil){
        dBadgets = [NSJSONSerialization JSONObjectWithData:badget options:kNilOptions error:nil];
    }
    dValue = [dConfiguration objectForKey:sButtonType];
    RowCount = (int)dValue.count;
    [_tvTable numberOfRowsInSection:RowCount];
    [self loadTable];
});

此变量在实现中声明为全局：

@implementation vcTableViewEventsManagerEvents {
    NSDictionary *dConfiguration;
}

我从未实现过alloc init代码：

dConfiguration = [[NSDictionary alloc] init];

这可能是问题吗？如果我总是初始化变量，这个错误不会发生？始终进行初始化是一个好习惯吗？我在哪里可以看到有关EXC_BAD_ACCESS的详细信息？

感谢您的帮助。

更新1

我已经尝试过看到所有评论的错误，也许我做错了，因为错误变量是nil这是屏幕拍摄：

在这个特定时间，变量dConfiguration表示0个键/值对，因为我添加了alloc init。

我尝试过双击并尽快更改tabbar项目，有时会工作，有时则不会。

更新2

正如你所说，这是错误的BT：

线程＃1：tid = 0x7bfdfd，0x2537dd52基金会newJSONString + 98, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x3fe64a2) frame #0: 0x2537dd52 Foundation newJSONString + 98 帧＃1：0x2537d300基金会newJSONValue + 1976 frame #2: 0x2537cf04 Foundation newJSONValue + 956 第3帧：0x2537d380基金会newJSONValue + 2104 frame #4: 0x2537ca80 Foundation - [_ NSJSONReader parseUTF8JSONData：skipBytes：options：] + 176 帧＃5：0x2537c88e基础-[_NSJSONReader parseData:options:] + 238 frame #6: 0x2537c718 Foundation + [NSJSONSerialization JSONObjectWithData：options：error：] + 156 帧＃7：0x00121b24 guestperience __43-[vcTableViewEventsManagerEvents checkJson]_block_invoke_2(.block_descriptor=0x17040f40) + 244 at vcTableViewEventsManagerEvents.m:298 frame #8: 0x00495b7e libdispatch.dylib _ dispatch_call_block_and_release + 10 帧＃9：0x00495b6a libdispatch.dylib _dispatch_client_callout + 22 frame #10: 0x0049a654 libdispatch.dylib _ dispatch_main_queue_callback_4CF + 1680 帧＃11：0x24b81bdc CoreFoundation __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 8 frame #12: 0x24b800d6 CoreFoundation __ CFRunLoopRun + 1574 帧＃13：0x24acf2e8 CoreFoundation CFRunLoopRunSpecific + 520 frame #14: 0x24acf0d4 CoreFoundation CFRunLoopRunInMode + 108 帧＃15：0x260bfac8 GraphicsServices GSEventRunModal + 160 frame #16: 0x291940b8 UIKit UIApplicationMain + 144 帧＃17：0x001cb6f0 guestperience main(argc=1, argv=0x00473b5c) + 106 at main.m:16 frame #18: 0x24777872 libdyld.dylib start + 2

更新3

我已在控制台中执行此命令以查看JSON，并且对我来说看起来是正确的：

(lldb) po (NSString *)[[NSString alloc] initWithData:serviceData encoding:4]

{
    "BackgroundImage": null,
    "ButtonGallery": null,
    "Buttons": null,
    "ButtonsEvents": [{
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "04 JUN 2016 - Horario: 11.00 - 18.00",
        "Id": 23,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_15f37703-f0a0-4f10-be70-76e0118fa9f9_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_15f37703-f0a0-4f10-be70-76e0118fa9f9_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "134",
        "ItemType": null,
        "JsonConfigFile": "134es",
        "Label": "Brazil Pool Party",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Brazil Pool Party",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "23 JUN 2016 - Horario: 20:00 - 01:00",
        "Id": 29,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_5af125bb-1bdf-4fcf-9306-3b565cdbb928_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_5af125bb-1bdf-4fcf-9306-3b565cdbb928_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "140",
        "ItemType": null,
        "JsonConfigFile": "140es",
        "Label": "Noche de San Juan",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche de San Juan",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "02 JUL 2016 - Horario: 21:00 - 1:00",
        "Id": 30,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_7227de52-8d27-4a65-bdf7-dea08e37b968_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_7227de52-8d27-4a65-bdf7-dea08e37b968_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "141",
        "ItemType": null,
        "JsonConfigFile": "141es",
        "Label": "Noche Amàre",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche Amàre",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "09 JUL 2016 - Horario: 22:00 - 00:00",
        "Id": 28,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_4ad05ca3-c345-4a6f-aeb9-972610056b86_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_4ad05ca3-c345-4a6f-aeb9-972610056b86_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "139",
        "ItemType": null,
        "JsonConfigFile": "139es",
        "Label": "Noche Flamenca Beach",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche Flamenca Beach",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "20 JUL 2016 - Horario: 19:00 - 22:00",
        "Id": 27,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_161bab39-5ac6-43a0-84c4-5c0fa764b5b0_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_161bab39-5ac6-43a0-84c4-5c0fa764b5b0_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "138",
        "ItemType": null,
        "JsonConfigFile": "138es",
        "Label": "Noche de luna llena",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche de luna llena",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "23 JUL 2016 - Horario: 21:00 - 00:00",
        "Id": 26,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_c657d56d-5f24-4f28-8d0c-66afb2fae1ad_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_c657d56d-5f24-4f28-8d0c-66afb2fae1ad_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "137",
        "ItemType": null,
        "JsonConfigFile": "137es",
        "Label": "Noche cubana",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche cubana",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "06 AGO 2016 - Horario: 22:00 - 00:00",
        "Id": 31,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_98032ab6-b689-42d6-b19b-6b82705478a3_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_98032ab6-b689-42d6-b19b-6b82705478a3_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "142",
        "ItemType": null,
        "JsonConfigFile": "142es",
        "Label": "Noche Flamenca Beach",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche Flamenca Beach",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "13 AGO 2016 - Horario: 21:00 - 00:00",
        "Id": 32,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_447f28d9-ed38-4482-868e-74743cbb5a89_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_447f28d9-ed38-4482-868e-74743cbb5a89_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "143",
        "ItemType": null,
        "JsonConfigFile": "143es",
        "Label": "Noche cubana",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Noche cubana",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "10 SEP 2016 - Horario: 11:00 - 18:00",
        "Id": 33,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_a7328a94-d64d-4fd4-b0a1-a2c126c8c92c_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_a7328a94-d64d-4fd4-b0a1-a2c126c8c92c_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "144",
        "ItemType": null,
        "JsonConfigFile": "144es",
        "Label": "Pool Party",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Pool Party",
        "ViewController": 21
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "17 SEP 2016 - Horario: 12:00 - 18:00",
        "Id": 25,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_9f8af8e5-56d7-433f-9661-9403196faad8_x320.jpg",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_9f8af8e5-56d7-433f-9661-9403196faad8_x320.jpg",
        "ImageRetinaHeighlighted": null,
        "Item": "136",
        "ItemType": null,
        "JsonConfigFile": "136es",
        "Label": "Oktoberfest",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Oktoberfest",
        "ViewController": 21
    }],
    "ButtonsPromotions": [{
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 18,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_ba95942c-1ece-4332-9f95-eb3f95738f41_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_ba95942c-1ece-4332-9f95-eb3f95738f41_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "126",
        "ItemType": null,
        "JsonConfigFile": "126es",
        "Label": "Desayuna con Nosotros",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Desayuna con Nosotros",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 19,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_3b9f1e44-5f33-4eb9-987b-5e50dcaed2a7_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_3b9f1e44-5f33-4eb9-987b-5e50dcaed2a7_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "127",
        "ItemType": null,
        "JsonConfigFile": "127es",
        "Label": "Disfruta de Nuestra Cena Buffet",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Disfruta de Nuestra Cena Buffet",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 20,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_f0ec90c9-3383-48f7-b5cf-28a236aee9e9_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_f0ec90c9-3383-48f7-b5cf-28a236aee9e9_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "128",
        "ItemType": null,
        "JsonConfigFile": "128es",
        "Label": "Alquiler de Bicicletas Vintage",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Alquiler de Bicicletas Vintage",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 21,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_f72a03bf-ddd2-486e-a289-cb3e82bd08db_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_f72a03bf-ddd2-486e-a289-cb3e82bd08db_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "129",
        "ItemType": null,
        "JsonConfigFile": "129es",
        "Label": "Parking",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Parking",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 22,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_3dd87e35-2ae3-4ef2-a70a-f1b44e41d27a_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_3dd87e35-2ae3-4ef2-a70a-f1b44e41d27a_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "130",
        "ItemType": null,
        "JsonConfigFile": "130es",
        "Label": "Ofertas de Grab & Go",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Ofertas de Grab & Go",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 13,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_b8187a48-1b03-4b29-a403-f03af8433c4f_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_b8187a48-1b03-4b29-a403-f03af8433c4f_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "92",
        "ItemType": null,
        "JsonConfigFile": "92es",
        "Label": "Habitación \"The One\"",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Habitación \"The One\"",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 14,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_fc20ec9b-2107-4828-9796-d5234dbe80fd_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_fc20ec9b-2107-4828-9796-d5234dbe80fd_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "98",
        "ItemType": null,
        "JsonConfigFile": "98es",
        "Label": "Disfruta de una Salida de Habitación más Tarde",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Disfruta de una Salida de Habitación más Tarde",
        "ViewController": 20
    }, {
        "BadgeCount": 0,
        "ClientId": 0,
        "Frequency": "",
        "Id": 15,
        "Image": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_be514668-27d0-4ee8-995e-0f8f89936c9b_x320.png",
        "ImageHeighlighted": null,
        "ImageIconTitle": "",
        "ImageRetina": "http:\/\/ServerCloud.CloudApp.net\/DesktopServerCloud\/ClientData\/4\/Images\/GVT_be514668-27d0-4ee8-995e-0f8f89936c9b_x320.png",
        "ImageRetinaHeighlighted": null,
        "Item": "103",
        "ItemType": null,
        "JsonConfigFile": "103es",
        "Label": "Habitación categoría superior",
        "LongTitle": null,
        "Selector": "btnAction:",
        "SubLabel": null,
        "Title": "Habitación categoría superior",
        "ViewController": 20
    }],
    "ButtonsTabList": null,
    "DatePeriod": null,
    "Details": null,
    "Disclaimer": null,
    "MessageList": null,
    "NoBooking": null,
    "NumberOfLines": 2,
    "Pins": null,
    "Selector": null,
    "ServiceType": null,
    "TabList": null,
    "Texts": null,
    "Titles": null,
    "Url": null,
    "UserCode": null
}

Answer 1

修改块内的变量时，必须使用__block说明符

__block NSDictionary *dConfiguration;


__block NSData *serviceData = data;
dispatch_async(dispatch_get_main_queue(), ^{
  //...
});

dispatch_get_main_queue（）上的EXC_BAD_ACCESS

1 个答案: