ios - 方法混合实现未发生

Question

我正在尝试学习 swizzling 的概念。

即使我添加了 method_exchangeImplementations，这些方法仍然没有被混合。知道我哪里出错了吗？

#import <objc/runtime.h>

@interface POCViewController ()

- (void)addSwizzle;
- (void)originalMethod;
- (void)swizzledMethod;

@end

@implementation POCViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

    //Add swizzle
    [self addSwizzle];

    //Call the original method
    [self originalMethod];
}

- (void)addSwizzle
{
    Method original, swizz;

    original = class_getClassMethod([self class], @selector(originalMethod));
    swizz = class_getClassMethod([self class], @selector(swizzledMethod));
    method_exchangeImplementations(original, swizz);
}

- (void)originalMethod
{
    NSLog(@"Inside original method");
}

- (void)swizzledMethod
{
    NSLog(@"Inside swizzled method");
    [self swizzledMethod];
}

Answer 1

您正在使用 class_getClassMethod 来获取实例方法的实现，您应该使用 class_getInstanceMethod 来代替。

method_exchangeImplementations 仍然以同样的方式使用