Hook~iOS用钩子实现代码注入(埋点方案)

想要为某各类添加钩子首先要建立这个类或父类的分类,运用runtime的方法交换的方法实现交换再调回原方法 这就是钩子的基本思路  运用lldb 查看方法的调用堆栈 就可以找到在这个方法之前调用的方法,然后我们拦截它,交换它!

lldb 的命令 thread backtrace  查看调用堆栈

找到你需要的拦截的方法

    Method applicationLanch = class_getInstanceMethod([self class],@selector(application: didFinishLaunchingWithOptions:));

    Method newApplicationLanch = class_getInstanceMethod([self class], @selector(configurationApplication: didFinishLaunchingWithOptions:));

    method_exchangeImplementations(applicationLanch, newApplicationLanch);

然后调回本身:

- (BOOL)configurationApplication:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    BOOL result = [self configurationApplication:application didFinishLaunchingWithOptions:launchOptions];

    NSLog(@"%@AppDelegate+Hook",

          [self class]);

    return result;

}

注意这两个方法已经交换所以实际调用的是application: didFinishLaunchingWithOptions: 这个方法,那么代理方法怎么拦截呢?

也是一样的只要拦截 交换setDelegate: 方法 在交换的方法中遵守代理 然后在这个方法里继续交换你想要交换的方法

#define GET_CLASS_CUSTOM_SEL(sel,class)  NSSelectorFromString([NSString stringWithFormat:@"%@_%@",NSStringFromClass(class),NSStringFromSelector(sel)])

- (void)fd_setDelegate:(id<UIScrollViewDelegate>)delegate {

    if ([self isMemberOfClass:[UIScrollView class]]) {

        if (![self isContainSel:GET_CLASS_CUSTOM_SEL(@selector(scrollViewWillBeginDragging:),[delegate class]) inClass:[delegate class]]) {

            [self swizzling_scrollViewWillBeginDragging:delegate];

        }

        [self fd_setDelegate:delegate];

    }

}

- (BOOL)isContainSel:(SEL)sel inClass:(Class)class {

    unsigned int count;

    

    Method *methodList = class_copyMethodList(class,&count);

    for (int i = 0; i < count; i++) {

        Method method = methodList[i];

        NSString *tempMethodString = [NSString stringWithUTF8String:sel_getName(method_getName(method))];

        if ([tempMethodString isEqualToString:NSStringFromSelector(sel)]) {

            return YES;

        }

    }

    return NO;

}