Question

plot2.graphPoints = graphPointsMutableArray;
//    plot2.graphPoints = @[LMGraphPointMake(CGPointMake(1, 25), @"1", @"34.5")];

如果我直接将plot2.graphPoints分配给一个NSArray，则它像第2行中那样工作正常，但是如果我像上面所示的第一个那样给它分配一个NSMutableArray，则应用程序会给我SIGABRT，但以下情况除外如下所示

2018-12-04 02:53:18.079192+0500 ****[10946:258059] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSSingleObjectArrayI point]: unrecognized selector sent to instance 0x60400001f8a0'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000011020c1cb __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010f720f41 objc_exception_throw + 48
    2   CoreFoundation                      0x000000011028c914 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
    3   CoreFoundation                      0x000000011018f178 ___forwarding___ + 1432
    4   CoreFoundation                      0x000000011018eb58 _CF_forwarding_prep_0 + 120
    5   Fandex                              0x000000010e144823 -[LMLineGraphView drawPlots] + 1939
    6   Fandex                              0x000000010e13d678 -[LMLineGraphView drawRect:] + 312
    7   UIKit                               0x0000000111f75c49 -[UIView(CALayerDelegate) drawLayer:inContext:] + 487
    8   QuartzCore                          0x0000000111b380d8 -[CALayer drawInContext:] + 267
    9   QuartzCore                          0x0000000111a4b6cf CABackingStoreUpdate_ + 254
    10  QuartzCore                          0x0000000111b3e1dd ___ZN2CA5Layer8display_Ev_block_invoke + 44
    11  QuartzCore                          0x0000000111b37b34 -[CALayer _display] + 1701
    12  QuartzCore                          0x0000000111ac521f _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 655
    13  QuartzCore                          0x0000000111af0a14 _ZN2CA11Transaction6commitEv + 500
    14  QuartzCore                          0x0000000111af1760 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 76
    15  CoreFoundation                      0x00000001101aedb7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    16  CoreFoundation                      0x00000001101aed0e __CFRunLoopDoObservers + 430
    17  CoreFoundation                      0x0000000110193324 __CFRunLoopRun + 1572
    18  CoreFoundation                      0x0000000110192a89 CFRunLoopRunSpecific + 409
    19  GraphicsServices                    0x0000000116ef29c6 GSEventRunModal + 62
    20  UIKit                               0x0000000111ea523c UIApplicationMain + 159
    21  Fandex                              0x000000010e1c7aff main + 111
    22  libdyld.dylib                       0x0000000115336d81 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

这就是我在NSMutableArray中添加对象的方式

NSMutableArray *graphPointsMutableArray = [[NSMutableArray alloc] init];
[graphPointsMutableArray addObject:@[LMGraphPointMake(CGPointMake(1, 25), @"1", @"34.5")]];

Answer 1

您的两行不相等。

此：

 plot2.graphPoints = @[LMGraphPointMake(CGPointMake(1, 25), @"1", @"34.5")];

将包含单个NSArray的{{1}}分配给LMGraphPoint

与此同时：

plot2.graphPoints

将包含一个[graphPointsMutableArray addObject:@[LMGraphPointMake(CGPointMake(1, 25), @"1", @"34.5")]]; plot2.graphPoints = graphPointsMutableArray;和一个NSMutableArray的{{1}}分配给NSArray

你想要

LMGraphPoint

即。删除plot2.graphPoints数组文字。

如果使用NSMutableArray而不是NSArray，则应用程序崩溃

1 个答案: