ios - Segmentation fault OR Stacktrace when using UIView with message forwarding feature of Objective-C -

the problem: given class inherits nsobject , has instance of uiview wrapped. class named uiviewwrapper. use uiviewwrapper e.g. 'addsubview' of uiview. uiviewwrapper should act 'normal' uiview class.

i utilizing "message forwarding" feature of objective-c try things working. in 'addsubview' calls made instance of uiviewwrapper , point messages forwarded correctly wrapped instance of uiview. program crashes either 'segmentation fault: 11' (memory problems) or stacktrace (see below).

my questions: possible @ all? if yes, 'message forwarding' best way it? if yes, missing here? if no, what's better approach solve kind of problem?

the code (omitting main.m , appdelegate.h since have usual contents):

//appdelegate.m @implementation appdelegate  - (bool) application : (uiapplication *) application didfinishlaunchingwithoptions : (nsdictionary *) launchoptions {   self.window = [[uiwindow alloc] initwithframe : [[uiscreen mainscreen] bounds]];   self.window.backgroundcolor = [uicolor whitecolor];    //a normal uiview -> works expected   //uiview *theview = [[uiview alloc] initwithframe : cgrectmake(50, 50, 50, 50)];   //[theview setbackgroundcolor : [uicolor yellowcolor]];    //the wrapped version -> fails when added rootview   uiviewwrapper *theview = [[uiviewwrapper alloc] init];    uiview *rootview = [[uiview alloc] init];   [rootview addsubview : theview];    uiviewcontroller *rootviewcontroller = [[uiviewcontroller alloc] init];   [rootviewcontroller setview : rootview];    self.window.rootviewcontroller = rootviewcontroller;   [self.window makekeyandvisible];   return yes; }  //uiviewwrapper.h #import <uikit/uikit.h>  @interface uiviewwrapper : nsobject  @end  //uiviewwrapper.m @interface uiviewwrapper() @property(nonatomic, strong) uiview *uiview;  @end  @implementation uiviewwrapper  - (nsmethodsignature *) methodsignatureforselector : (sel) selector {   return [uiview instancemethodsignatureforselector : selector]; }  -(void) forwardinvocation : (nsinvocation *) forwardedinvocation {   if (!self.uiview) {       self.uiview = [[uiview alloc] initwithframe : cgrectmake(50, 50, 50, 50)];       [self.uiview setbackgroundcolor : [uicolor redcolor]];   }    [forwardedinvocation invokewithtarget : self.uiview]; }  @end 

the important parts of stacktrace appears sometimes. other time segmentation fault: 11

jan 27 13:55:09 dirks-macbook-air showcase[15741]: +[__nsblockvariable__ superlayer]: unrecognized selector sent class 0x2df82b4 jan 27 13:55:09 dirks-macbook-air showcase[15741]: *** terminating app due uncaught exception 'nsinvalidargumentexception', reason: '+[__nsblockvariable__ superlayer]: unrecognized selector sent class 0x2df82b4' *** first throw call stack: (     0   corefoundation                      0x0253fa14 __exceptionpreprocess + 180     1   libobjc.a.dylib                     0x028a9e02 objc_exception_throw + 50     2   corefoundation                      0x02548c03 +[nsobject(nsobject) doesnotrecognizeselector:] + 275     3   corefoundation                      0x024866bd ___forwarding___ + 1037     4   corefoundation                      0x0248628e _cf_forwarding_prep_0 + 14     5   uikit                               0x00dce092 -[uiview(internal) _addsubview:positioned:relativeto:] + 1452     6   uikit                               0x00dbc8e4 -[uiview(hierarchy) addsubview:] + 56     7   showcase                            0x001dcb4b -[appdelegate application:didfinishlaunchingwithoptions:] + 343 

maybe if clarify trying solve, can more. have feeling there's no point in finding solution , choosing different approach better. case in objective-c. better stick "cocoa way" of doing things.

basically, you're calling addsubview method object of incorrect class argument. see picture #1. , that's reason crash.