2

我已经为 s 实现了一个 Swizzling 类别，当它们出现时UIViewController，它就是s：NSlog

#import "UIViewController+Logger.h"
#import <objc/runtime.h>

@implementation UIViewController (Logger)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];

        SEL originalSelector = @selector(presentViewController:animated:completion:);
        SEL swizzledSelector = @selector(logAndPresentViewController:animated:completion:);

        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);
        }

    });
}

#pragma mark - Method Swizzling

- (void)logAndPresentViewController:(UIViewController *)viewControllerToPresent
                     animated:(BOOL)flag
                   completion:(void (^)(void))completion {
    NSLog(@"viewControllerToPresent: %@", viewControllerToPresent);

    [self logAndPresentViewController:viewControllerToPresent animated:flag completion:completion];
}

@end

显然，这仅在 swizzled 应用程序内工作正常，但我想知道我是否也可以“挂钩”共享presentViewController，以便在我的应用程序外部呈现视图时调用它。我在想也许可以UIViewController动态加载dlopen而不是获取指向它的全局图像符号的指针。可能吗？如果不是——不是吗？

免责声明 - 我这样做是为了在我自己的开发设备上进行调试，并且不会将应用程序上传到 App Store。

4

0 回答 0