ios - 将参数添加到协议（委托）

Question

我想向委托方法添加一个参数（来自 NSXMLParserDelegate）

这是迄今为止的方法：

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{
    // save the characters for the current item...
    if ([string   isEqual: @"off"]) {
         myObject.isON = NO; //doesn't know what is myObject
    }

我想要的是 ：

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string:(MyObject*)anObject{
    // save the characters for the current item...
    if ([string   isEqual: @"off"]) {
         anObject.isON = NO;
    }

谢谢

Answer 1

首先，您需要子类化您的NSXMLParser，添加新delegate属性调用它subclassDelegate或类似的东西，这样您就可以区分超类的委托。在 init 中成为您的超类的代表self.delegate = self；

响应委托方法并将您不想覆盖的方法转发到self.subclassDelegate响应您要覆盖的方法并在子类协议中覆盖它。

这是示例：

    @protocol  MyXMLParserDelegate;
@interface MyXMLParser : NSXMLParser<NSXMLParserDelegate>
@property (weak) id<MyXMLParserDelegate> subclassDelegate;
@end

@protocol  MyXMLParserDelegate <NSObject>
- (void)parserDidStartDocument:(NSXMLParser *)parser;
// this is the method that you override
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string withObject:(id)object;
@end

然后在.m

@implementation MyXMLParser

- (id)init
{
    self = [super init];
    if(self) {
        self.delegate = self;
    }
    return self;
}


#pragma mark - repspond to NSXMLParser delegate

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
    [self.subclassDelegate parser:parser foundCharacters:string withObject:yourObject];
}