iOS 利用RunTime检测控制器是否销毁

本文是在控制器的基础上添加了一个 Category ，只需导入 Category 并引用头文件，不需要在项目里引用其他代码，就可以检测控制器是否被销毁。具体代码如下：

UIViewController+Example.h

//
//  UIViewController+Example.h
//
//  Created by TL on 2017/4/6.
//  Copyright © 2017年 TL. All rights reserved.
//

#import "UIViewController.h"

@interface RootViewController (Example)

@property (copy, nonatomic) NSString *method;

@end

UIViewController+Example.m

//
//  UIViewController+Example.m
//
//  Created by TL on 2017/4/6.
//  Copyright © 2017年 TL. All rights reserved.
//

#import "UIViewController+Example.h"

@implementation UIViewController (Example)


#pragma mark - swizzle
+ (void)load
{
    Method method1 = class_getInstanceMethod([self class], NSSelectorFromString(@"dealloc"));
    Method method2 = class_getInstanceMethod([self class], @selector(deallocSwizzle));
    method_exchangeImplementations(method1, method2);
}

- (void)deallocSwizzle
{
    NSLog(@"%@被销毁了", self);
}

static char MethodKey;
- (void)setMethod:(NSString *)method
{
    objc_setAssociatedObject(self, &MethodKey, method, OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (NSString *)method
{
    return objc_getAssociatedObject(self, &MethodKey);
}

@end

没有一蹴而就的天才，只有不断点亮天赋的勤者