发送给不可变对象的变异方法”

Question

我试图从字典添加对象到数组。 在其他部分，我得到这个错误

发送给不可变对象的变异方法”

NSMutableDictionary *selectedDict = [NSMutableDictionary new];
    [selectedDict setObject:editedLineItem forKey:@"Text"];
    [selectedDict setObject:@"fa-check" forKey:@"IconClass"];
    NSMutableArray *tagListDictionary = [NSMutableArray new];
    [tagListDictionary addObject:selectedTagsArray];
    LineItemsStorage *linestorage = [LineItemsStorage sharedManager];
    if(![linestorage.packagesArray valueForKey:@"Id"])
    {
        [linestorage.selectedLineItemsAndTagsArray addObject:selectedDict];
    }
    else{        [[linestorage.packagesArray valueForKey:@"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]];
    }

-[ NSCFArray insertObject：atIndex：]：发送给不可变对象的变异方法'***首次调用堆栈：（0 CoreFoundation 0x00000001154a1d85 __exceptionPreprocess + 165 1 libobjc.A.dylib 0x0000000114f15deb objc_exception_throw + 48 2 CoreFoundation 0x00000001154NS1ccdd ：： + 205 3 CoreFoundation 0x0000000115497b0a-[__ NSCFArray insertObject：atIndex：] + 106 4 FlatPebble 0x000000010f276014-[LineItemViewController okayAction] + 836 5 UIKit 0x0000000113809a8d-[UIApplication sendAction：to：from：forEvent：] + 92 6 UIKit 0x000000011397Control sendAction：to：forEvent：] + 67 7 UIKit 0x000000011397d143-[UIControl _sendActionsForEvents：withEvent：] + 327 8 UIKit 0x000000011397c263-[UIControl touchesEnded：withEvent：] + 601 9 UIKit 0x000000011387c99f-[UIWindow _sendTouches011Eventd] -6 UIKit 0x000000011387c99f -d [UIWindow sendEvent：] + 865 11 UIKit 0x0000000113828dc6-[UIApplication sendEvent：] + 263 12 UIKit 0x0000000113802553 _UIApplicationHandleEventQueu E + 6660 13的CoreFoundation 0x00000001153c7301 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 17 14的CoreFoundation 0x00000001153bd22c __CFRunLoopDoSources0 + 556 15的CoreFoundation 0x00000001153bc6e3 __CFRunLoopRun + 867 16的CoreFoundation 0x00000001153bc0f8 CFRunLoopRunSpecific + 488个17 GraphicsServices 0x0000000116e5cad2 GSEventRunModal + 161 18的UIKit 0x0000000113807f09 UIApplicationMain + 171 19 ********** * 0x000000010f348c2f main + 111 20 libdyld.dylib 0x0000000115d9992d start +1）

Answer 1

使用此代码

 NSMutableDictionary *selectedDict = [[NSMutableDictionary new]mutableCopy];
    [selectedDict setObject:editedLineItem forKey:@"Text"];
    [selectedDict setObject:@"fa-check" forKey:@"IconClass"];
    NSMutableArray *tagListDictionary = [[NSMutableArray new]mutableCopy];
    [tagListDictionary addObject:selectedTagsArray];
    LineItemsStorage *linestorage = [LineItemsStorage sharedManager];
    if(![linestorage.packagesArray valueForKey:@"Id"])
    {
        [linestorage.selectedLineItemsAndTagsArray addObject:selectedDict];
    }
    else{        [[linestorage.packagesArray valueForKey:@"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]];
    }

Answer 2

假设您的packagesArray包含一个数组，该数组包含一个或多个具有LineItems属性的对象（碰巧也是一个数组）； 您的问题在这里：

[[linestorage.packagesArray valueForKey:@"LineItems"]addObject:[NSMutableArray arrayWithObject:selectedDict]]

将其分解等效于：

 NSArray* packagesLineItems = [linestorage.packagesArray valueForKey:@"LineItems"];
 NSMutableArray* selected = [NSMutableArray arrayWithObject:selectedDict];
 [packagesLineItems addObject:selected];

因此，您的问题是valueForKey的返回类型（在数组上调用时），或者您要对其执行的操作。