Adding Methods Dynamically

Question

I am trying to find this method in the link to runj_cpp_cppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp

BOOL class_addMethod(Class cls, SEL name, IMP imp, const char *types)

I want to add a new method, for example:

- [AClass drawWithFrame:(NSRect)rect inView:(id)view]

So far I have written a C function:

void drawWithFrameInView(id this, SEL this_cmd, NSRect frame, id view){
...
} 

Now I am ready to do:

BOOL success = class_addMethod(NSClassFromString(@"AClass"), 
                               @selector(drawWithFrame:inView:), 
                               (IMP)drawWithFrameInView, 
                               "v@:@:@:");

but it successnever will be YES, I tried the same approach with methods with simpler signatures, and it worked. Therefore, I think the problem is the last parameter:"v@:@:@:"

What should I pass in this case for my new method to work?

Answer 1

This will work:

char *types = [[NSString stringWithFormat:@"v@:%s@", @encode(NSRect)] UTF8String];

BOOL success = class_addMethod(NSClassFromString(@"MyClass"), 
                               @selector(drawWithFrame:inView:), 
                               (IMP)drawWithFrameInView, 
                               types);

, , , NSRect , typedef - struct.

.