iOS 应用程序开发- NSMutableURLRequest 为零

Question

我是 iOS 开发的新手。现在我面临一个奇怪的问题。当我在 iPhone 5 模拟器上运行以下代码时，一切正常。然而，它在我真正的 iPhone 5 上不起作用。有人可以帮我帮我找出原因吗？ objective-C : NSError *错误；

NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setValue:@1 forKey:@"driverId"];
[dictionary setValue:@1 forKey:@"busId"];
[dictionary setValue:@1 forKey:@"lineId"];

NSData *postData = nil;
NSString *requestData = @"";
NSString *urlPath = @"myurl";
if([NSJSONSerialization isValidJSONObject:dictionary]){
    postData = [NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:nil];
    NSString *str = [[NSString alloc] initWithData:postData encoding:NSUTF8StringEncoding];
    requestData = [requestData stringByAppendingString:str];

    postData = [NSData dataWithBytes:[requestData UTF8String] length:[requestData length]];
}

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];
NSURL *url = [NSURL URLWithString:urlPath];

NSMutableURLRequest *request=[NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:postData];

NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *response = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];

NSDictionary *responseDic = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableLeaves error:&error];
NSString *status = [responseDic objectForKey:@"status"];

通过对比“request”和“nil”，我发现 request 是 nil。

错误是:

2014-07-23 19:13:54.698 ShuttleBusForDriver[2958:60b] 无请求2014-07-23 19:13:54.699 ShuttleBusForDriver[2958:60b] 响应日期:(空)2014-07-23 19:13:54.701 ShuttleBusForDriver[2958:60b] * 由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因:“数据参数为零”* 首先抛出调用堆栈:(0x2fc96ecb 0x3a431ce7 0x2fc96e0d 0x30624967 0xdfa55 0xde785 0x324cca33 0x324cc7f1 0x32658bf3 0x3257646f 0x32576279 0x32576211 0 x324c82e5 0x3214431b 0x3213fb3f 0x3213f9d1 0x3213f3e5 0x3213f1f7 0x324cb99f 0x2fc61faf 0x2fc61477 0x2fc5fc67 0x2fbca729 0x2fb ca50b 0x34b396d3 0x3252b871 0xdc69c 0xdc6d8 0x3a92fab7)libc++abi.dylib:以 NSException 类型的未捕获异常终止

Answer 1

@JingDu 首先抱歉，由于我的 stackoverflow 网站问题，我无法添加评论。符号化的崩溃报告是符号化的报告，它看起来像这样:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'
*** First throw call stack:
(
 0   CoreFoundation                      0x0284d1e4 __exceptionPreprocess + 180
 1   libobjc.A.dylib                     0x01c7e8e5 objc_exception_throw + 44
 2   CoreFoundation                      0x0284cfbb +[NSException raise:format:] + 139
 3   Foundation                          0x017b7bd2 +[NSJSONSerialization JSONObjectWithData:options:error:] + 67
 4   Test                                0x00003eb8 -[ViewController viewDidLoad] + 136
 5   UIKit                               0x0085033d -[UIViewController loadViewIfRequired] + 696
 6   UIKit                               0x008505d9 -[UIViewController view] + 35
 7   UIKit                               0x00770267 -[UIWindow addRootViewControllerViewIfPossible] + 66
 8   UIKit                               0x007705ef -[UIWindow _setHidden:forced:] + 312
 9   UIKit                               0x0077086b -[UIWindow _orderFrontWithoutMakingKey] + 49
 10  UIKit                               0x0077b3c8 -[UIWindow makeKeyAndVisible] + 65
 11  UIKit                               0x0072bbc0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 2097
 12  UIKit                               0x00730667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824
 13  UIKit                               0x00744f92 -[UIApplication handleEvent:withNewEvent:] + 3517
 14  UIKit                               0x00745555 -[UIApplication sendEvent:] + 85
 15  UIKit                               0x00732250 _UIApplicationHandleEvent + 683
 16  GraphicsServices                    0x0255cf02 _PurpleEventCallback + 776
 17  GraphicsServices                    0x0255ca0d PurpleEventCallback + 46
 18  CoreFoundation                      0x027c8ca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
 19  CoreFoundation                      0x027c89db __CFRunLoopDoSource1 + 523
 20  CoreFoundation                      0x027f368c __CFRunLoopRun + 2156
 21  CoreFoundation                      0x027f29d3 CFRunLoopRunSpecific + 467
 22  CoreFoundation                      0x027f27eb CFRunLoopRunInMode + 123
 23  UIKit                               0x0072fd9c -[UIApplication _run] + 840
 24  UIKit                               0x00731f9b UIApplicationMain + 1225
 25  Test                                0x000026bd main + 141
 26  libdyld.dylib                       0x02d30725 start + 0
 )
libc++abi.dylib: terminating with uncaught exception of type NSException

它来自与您类似的代码:

 * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil' * First throw call stack: (0x2fc96ecb 0x3a431ce7 0x2fc96e0d 0x30624967 0xdfa55 0xde785 0x324cca33 0x324cc7f1 0x32658bf3 0x3257646f 0x32576279 0x32576211 0x324c82e5 0x3214431b 0x3213fb3f 0x3213f9d1 0x3213f3e5 0x3213f1f7 0x324cb99f 0x2fc61faf 0x2fc61477 0x2fc5fc67 0x2fbca729 0x2fbca50b 0x34b396d3 0x3252b871 0xdc69c 0xdc6d8 0x3a92fab7) libc++abi.dylib: terminating with uncaught exception of type NSException