Question

我想从网址和JSON解析NSLog。这是我的网址：http://api.kivaws.org/v1/loans/search.json?status=fundraising

这是我的代码。当我运行我的代码时崩溃.....

NSURL * url=[NSURL URLWithString:@"http://api.kivaws.org/v1/loans/search.json?status=fundraising"];
NSData* data = [NSData dataWithContentsOfURL:url];
NSError* error;
NSDictionary* json = [NSJSONSerialization
                          JSONObjectWithData:data options:kNilOptions
                          error:&error];

NSLog(@"%@",json);

请帮帮我....这是我的崩溃错误：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000104827f35 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000106905bb7 objc_exception_throw + 45
    2   CoreFoundation                      0x0000000104827e6d +[NSException raise:format:] + 205
    3   Foundation                          0x00000001065aa1bf +[NSJSONSerialization JSONObjectWithData:options:error:] + 67
    4   json                                0x00000001046608b9 -[ViewController viewDidLoad] + 185
    5   UIKit                               0x00000001052d3a90 -[UIViewController loadViewIfRequired] + 738
    6   UIKit                               0x00000001052d3c8e -[UIViewController view] + 27
    7   UIKit                               0x00000001051f2ca9 -[UIWindow addRootViewControllerViewIfPossible] + 58
    8   UIKit                               0x00000001051f3041 -[UIWindow _setHidden:forced:] + 247
    9   UIKit                               0x0000000112eac7b0 -[UIWindowAccessibility _orderFrontWithoutMakingKey] + 68
    10  UIKit                               0x00000001051ff72c -[UIWindow makeKeyAndVisible] + 42
    11  UIKit                               0x00000001051aa061 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 2628
    12  UIKit                               0x00000001051acd2c -[UIApplication _runWithMainScene:transitionContext:completion:] + 1350
    13  UIKit                               0x00000001051abbf2 -[UIApplication workspaceDidEndTransaction:] + 179
    14  FrontBoardServices                  0x000000010b6692a3 __31-[FBSSerialQueue performAsync:]_block_invoke + 16
    15  CoreFoundation                      0x000000010475d53c __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    16  CoreFoundation                      0x0000000104753285 __CFRunLoopDoBlocks + 341
    17  CoreFoundation                      0x0000000104753045 __CFRunLoopRun + 2389
    18  CoreFoundation                      0x0000000104752486 CFRunLoopRunSpecific + 470
    19  UIKit                               0x00000001051ab669 -[UIApplication _run] + 413
    20  UIKit                               0x00000001051ae420 UIApplicationMain + 1282
    21  json                                0x0000000104660ca3 main + 115
    22  libdyld.dylib                       0x0000000107089145 start + 1
    23  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

如果您需要知道失败的原因，请从

开始

NSError* error = nil;    
NSData* data = [NSData dataWithContentsOfURL:url options: nil error:&error]:

然后，如果失败，您可以使用

查看错误

NSLog@"Error description = %@", [error localizedDescription];

此外，正如其他人所说，您应该更改代码，以便异步提取URL。相反，对于非文件URL，请考虑使用NSSession类的dataTaskWithURL：completionHandler：方法。有关详细信息，请参阅URL Loading System Programming Guide。

从url iOS解析json时崩溃应用程序

1 个答案: