1 What is @selector
c selector similar to the function pointers.
c function pointer:
int add(int val) {
return val + 1;
}
int (* c_func)(int val)
_func = add;
objective-c selector:
@interface foo
-(int)add:int val;
@end
SEL class_func;
class_func=@selector(add:int);
@selector method is to find the current class, and [@selector object (method name: Method parameter ..)]; Methods object corresponding to the corresponding class;
When looking for a class method, in addition to the method name, parameter also check one condition;
The method can be used to find the string variable name SEL = NSSelectorFromString (String method name);
Variables can be run with the SEL reverse isolated string method name: NSString * variable name = NSStringFromSelector (SEL parameter);
2 selector What is the use
3 in your code How selector
After obtaining the appropriate values, how to deal with SEL value of it, it is still the same as function pointers, it is the implementation of
a function pointer execution, (there are a few equivalents
*c_func(10);
c_func(10);
SEL execution variables. PerformSelecor be performed using the method.
[ Object the performSelector: the SEL variable withObject: Parameter. 1 withObject: parameter 2] ;