建立一个UIViewcontroller的category
</pre><pre name="code" class="objc">#import "UIViewController+AOP.h"
#import <objc/runtime.h>
@implementation UIViewController (AOP)
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Class class = [self class];
// Class class = object_getClass((id)self);
swizzleMethod(class, @selector(viewDidLoad), @selector(aop_viewDidLoad));
});
}
void swizzleMethod(Class class, SEL originalSelector, SEL swizzledSelector) {
Method originalMethod = class_getInstanceMethod(class, originalSelector);
Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
BOOL didAddMethod =
class_addMethod(class,originalSelector,method_getImplementation(swizzledMethod),method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(class,swizzledSelector,method_getImplementation(originalMethod),method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
}
- (void)aop_viewDidLoad {
[self aop_viewDidLoad];
}