iOS - Tips - hook 代理方法

• hook 代理方法入口

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Method originMethod = class_getInstanceMethod([self class], @selector(setDelegate:));
        Method newMethod = class_getInstanceMethod([self class], @selector(hook_setDelegate:));
        method_exchangeImplementations(originMethod, newMethod);
    });
}

• 方法实现

static void Hook_Method(Class originalClass, SEL originalSel, Class replacedClass, SEL replacedSel, SEL noneSel) {
    Method originalMethod = class_getInstanceMethod(originalClass, originalSel);
    Method replacedMethod = class_getInstanceMethod(replacedClass, replacedSel);
    if (!originalMethod) {
        Method noneMethod = class_getInstanceMethod(replacedClass, noneSel);
        BOOL addNoneMethod = class_addMethod(originalClass, originalSel, method_getImplementation(noneMethod), method_getTypeEncoding(noneMethod));
        if (addNoneMethod) {
            NSLog(@"******** 没有实现 (%@) 方法，手动添加成功！！", NSStringFromSelector(originalSel));
        }
        return;
    }

    BOOL addMethod = class_addMethod(originalClass, replacedSel, method_getImplementation(replacedMethod), method_getTypeEncoding(replacedMethod));
    if (addMethod) {
        NSLog(@"******** 实现了 (%@) 方法并成功 Hook 为 --> (%@)", NSStringFromSelector(originalSel), NSStringFromSelector(replacedSel));
        Method newMethod = class_getInstanceMethod(originalClass, replacedSel);
        method_exchangeImplementations(originalMethod, newMethod);
    } else {
        NSLog(@"******** 已替换过，避免多次替换 --> (%@)",NSStringFromClass(originalClass));
    }
}

• plus

- (void)hook_setDelegate:(id<UITableViewDelegate>)delegate {
    SEL originalSEL = @selector(tableView:didSelectRowAtIndexPath:);
    SEL newSEL = @selector(hook_tableView:didSelectRowAtIndexPath:);
    
    Hook_Method([delegate class], originalSEL, [self class], newSEL, originalSEL);
    
    [self hook_setDelegate:delegate];
}

#pragma mark - exchangeMethod

// 代理没有实现方法, 添加实现
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"%s", __func__);
}

// 代理实现了方法, 进行
- (void)hook_tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"%s", __func__);
    [self hook_tableView:tableView didSelectRowAtIndexPath:indexPath];
}