2023-05-24

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

@implementation UIViewController (LoadEvent)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];
        
        SEL originalSelector = @selector(viewDidLoad);
        SEL swizzledSelector = @selector(swizzled_viewDidLoad);
        
        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)swizzled_viewDidLoad {
    // 在这里执行你想要的操作，用于检测 View Controller 的加载事件
    NSLog(@"ViewController loaded: %@", self);
    // 调用原始的 viewDidLoad 方法
    [self swizzled_viewDidLoad];
}
@end