Cocoa advanced Development Runtime primary basic variables

# # # To do iOS development time is not short, it is time to see what they have written to share the object copy:

id object_copy(id// 对象释放 id object_dispose(id obj)TsetClass *obj = [TsetClassnew];id objTest =object_copy(obj,sizeof(obj));

(LLDB) PO &obj
0x00007fff54a7cb08
(LLDB) PO &objtest
0x00007fff54a7cb00
There is no doubt that the printed memory address is not the same, this method is similar to a deep copy of the pointer

Deep copy and shallow copy

• Deep copy and shallow copy
  A shallow copy copies the object itself, and the attributes and objects contained in the object do not replicate.
  Deep copy copies all, including object properties and other objects.
  The foundation framework supports replicated classes, which by default are shallow copy
• Custom copies of objects
  object has the copy attribute, must implement the Nscopying,nsmutablecopying protocol, implement the Copywithzone method and Mutablecopywithzone method of the protocol.
  The difference between deep copy and shallow copy lies in the realization of Copywithzone method
  Object_dispose (objtest);//equivalent to [objtest release]; This method is just the encapsulation of the runtime.
  Execute [objtest release] again to know what errors are reported;

List:testruntime (1034,0x111b66300) malloc: * error for object 0x7ffe1a75b940:pointer being freed is not allocat Ed

Changing the class of an object/getting the object's class

• Changing the class of an object

TsetClass *obj1 = [TsetClass new]; Class aClass =object_set0x7f8e4bd14480>(lldb) po aClassTsetClass有没有出乎你的想象0.0.

• Gets the class of the object

TsetClass *obj2 = [TsetClass new];Class aLogClass =object_getClass(obj2);(lldb) po aLogClassTsetClassNSString *className = [NSStringstringWithCString:object_getClassName(obj2)encoding:NSUTF8StringEncoding];NSLog(@"className:%@", className);(lldb) po classNameTsetClass

• Add a method to a class

BOOLClass_addmethod (Class cls,sel name,imp IMP,Const Char*types) Tsetclass *instance = [[Tsetclassalloc]init]; method Add Class_addmethod ([Tsetclass class],@selector(Ocmethod:), (IMP) cfunction,"[Email protected]:@]);if([Instance Respondstoselector:@selector(Ocmethod:)]) {NSLog(@"Yes, instance respondstoselector: @selector (ocmethod:)"); }Else{NSLog(@"Sorry"); }intA = (int) [Instance ocmethod:@"I am an OC Method,c function implementation"];NSLog(@"a:%d", a);intCfunction (ID  Self, SEL _cmd,NSString*STR) {NSLog(@"%@", str);return 520;//Return a value randomly}

• Get all methods of a class/all properties

  Get all methods of a class

u_int count;Method* methods= class_copyMethodList([UIViewController class], &count);for0{     SEL name = method_getName(methods[i]);     NSString *strName = [NSString stringWithCString:sel_getName(name)encoding:NSUTF8StringEncoding];//        NSLog(@"%@",strName);}

Get all properties of a class

u_int count;objc_property_t *properties=class_copyPropertyList([TsetClass class], &count);for (int0; i < count ; i++) {    constchar* propertyName =property_getName(properties[i]);        NSString *strName = [NSString stringWithCString:propertyName encoding:NSUTF8StringEncoding];        NSLog(@"%@",strName);    }

• Gets the value of the global variable (myfloat is a property variable for the class)

float myFloatValue;object_getInstanceVariable(self,"myFloat"(void*)&myFloatValue);NSLog(@"%f", myFloatValue);

• Set the value of a global variable

float10.00f;unsignedint addr = (unsignedint)&newValue;object_setInstanceVariable(self,"myFloat", *(float**)addr);

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Cocoa advanced Development Runtime primary basic variables