hook delegate 正确姿势

核心hook方法：网上有类似hook方式，但没考虑继承和子类的问题，会导致循环调用crash。

NSDictionary * checkIfObject(Class object,SEL selector) {
    Class objSuperClass = [object superclass];
    while (objSuperClass != Nil) {
        BOOL isMethodOverridden = [object methodForSelector: selector] != [objSuperClass instanceMethodForSelector: selector];
        if (isMethodOverridden) {
            return @{@"class":objSuperClass,@"exist":@(YES)};
        }
        objSuperClass = [objSuperClass superclass];
    }
    return @{@"class":object,@"exist":@(NO)};
}

void exchangeMethod(Class oriClass, SEL originalSel, Class replacedClass, SEL replacedSel, SEL orginReplaceSel) {
    NSDictionary *dict = checkIfObject(oriClass, originalSel);
    Class originalClass = dict[@"class"];
    BOOL exist = [dict[@"exist"] boolValue];
    Method originalMethod = class_getInstanceMethod(originalClass, originalSel);
    Method replacedMethod = class_getInstanceMethod(replacedClass, replacedSel);
    if (!exist) {
        Method orginReplaceMethod = class_getInstanceMethod(replacedClass, orginReplaceSel);
        BOOL didAddOriginMethod = class_addMethod(originalClass, originalSel, method_getImplementation(orginReplaceMethod), method_getTypeEncoding(orginReplaceMethod));
        if (didAddOriginMethod) {
            NSLog(@"did Add Origin Replace Method");
        }
        return;
    }
    BOOL didAddMethod = class_addMethod(originalClass, replacedSel, method_getImplementation(replacedMethod), method_getTypeEncoding(replacedMethod));
    if (didAddMethod) {
        Method newMethod = class_getInstanceMethod(originalClass, replacedSel);
        method_exchangeImplementations(originalMethod, newMethod);
    }
}

使用 案例：（XXXX 前缀）注意实现方式

- (void)XXXX_setNavigationDelegate:(id<WKNavigationDelegate>)navigationDelegate {

    [self XXXX_setNavigationDelegate:navigationDelegate];

    exchangeMethod([navigationDelegate class], @selector(webView:decidePolicyForNavigationAction:decisionHandler:), [self class], @selector(XXXX_webView:decidePolicyForNavigationAction:decisionHandler:),@selector(XXXX_oriReplace_webView:decidePolicyForNavigationAction:decisionHandler:));
    
    exchangeMethod([navigationDelegate class], @selector(webView:didStartProvisionalNavigation:), [self class], @selector(XXXX_webView:didStartProvisionalNavigation:),@selector(XXXX_oriReplace_webView:didStartProvisionalNavigation:));
    
    exchangeMethod([navigationDelegate class], @selector(webView:didFinishNavigation:), [self class], @selector(XXXX_webView:didFinishNavigation:),@selector(XXXX_oriReplace_webView:didFinishNavigation:));
    
    exchangeMethod([navigationDelegate class], @selector(webView:didFailProvisionalNavigation:withError:), [self class], @selector(XXXX_webView:didFailProvisionalNavigation:withError:),@selector(XXXX_oriReplace_webView:didFailProvisionalNavigation:withError:));
    
    exchangeMethod([navigationDelegate class], @selector(webView:didFailNavigation:withError:), [self class], @selector(XXXX_webView:didFailNavigation:withError:),@selector(XXXX_oriReplace_webView:didFailNavigation:withError:));
}