swizzle function

NSObject+hook.m

@interface NSObject (hook)
+ (void)switchClassFuction:(NSString *)originalSelectorName swizzledSelector:(NSString *)swizzledSelectorName;
+ (void)switchInstanceFuction:(NSString *)originalSelectorName sel2:(NSString *)swizzledSelectorName;
@end

@implementation NSObject (hook)

+ (void)switchClassFuction:(NSString *)originalSelectorName swizzledSelector:(NSString *)swizzledSelectorName {
    Class class = object_getClass((id)self);
    SEL originalSelector = NSSelectorFromString(originalSelectorName);
    SEL swizzledSelector = NSSelectorFromString(swizzledSelectorName);
    Method originalMethod = class_getClassMethod(class, originalSelector);
    Method swizzledMethod = class_getClassMethod(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)switchInstanceFuction:(NSString *)originalSelectorName sel2:(NSString *)swizzledSelectorName {
    Class class = [self class];
    SEL originalSelector = NSSelectorFromString(originalSelectorName);
    SEL swizzledSelector = NSSelectorFromString(swizzledSelectorName);
    
    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);
    }
}

@end