NSXMLParserDelegate编译问题 - iPhone SDK 30. vs 4.0 [英] NSXMLParserDelegate compile problem - iPhone SDK 30. vs 4.0

问题描述

我的头文件定义如下：

#import <Foundation/Foundation.h>

@interface Warning: NSObject  { 

在我的.m文件中我做：

In my .m file I do:

NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL:url];
[parser setDelegate:self];

这个编译并在3.0以下工作正常。

This compiles and works just fine under 3.0.

如果我尝试使用4.0编译，我会收到此错误：

If I try to compile with 4.0 I get this error:

未实现
'NSXMLParserDelegate'协议

does not implement the 'NSXMLParserDelegate' protocol

如果我添加：

@interface Warning: NSObject <NSXMLParserDelegate>  { 

它用4.0编译好，但是当我尝试用3.0编译时，我得到：

It compiles fine with 4.0, but when I try to compile with 3.0 I get:

错误：无法找到'NSXMLParserDelegate'的协议
声明

error: cannot find protocol declaration for 'NSXMLParserDelegate'

正确找到Foundation框架。添加NSXMLParser.h无济于事。

The Foundation framework is found correctly. Adding NSXMLParser.h doesn't help.

任何帮助都将不胜感激。

Any help would be appreciated.

谢谢

推荐答案

根据库参考文档，NSXMLParser不需要严格的NSXMLParserDelegate实现：

According to the library reference documentation, NSXMLParser doesn't require a strict NSXMLParserDelegate implementation :

- (void)setDelegate:(id)delegate
- (id)delegate

NSXMLParser动态检查所需的委托方法可用性。

NSXMLParser checks needed delegate methods availability on the fly.

如果NSXMLParser需要NSXMLParserDelegate完全实现，则访问者将是：

If NSXMLParser was requiring a NSXMLParserDelegate full implementation, the accessors would be :

- (void)setDelegate:(id<NSXMLParserDelegate>)delegate
- (id<NSXMLParserDelegate>)delegate

我猜这就是为什么框架中没有实际定义的NSXMLParserDelegate协议。

I guess that's why there is no NSXMLParserDelegate protocol actually defined in the framework.

所以，这个界面对我来说似乎是正确的：

So, that interface seems correct to me :

#import <Foundation/Foundation.h>

@interface Warning: NSObject  { 

你所要做的就是实施你需要的委托方法 。

All you have to do is implement the delegate methods you need for.

编辑：

您可以尝试使用预处理器宏来激活或停用协议使用声明：

You could try using preprocessor macros to activate or deactivate the protocol usage declaration :

#if __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_4_0
@interface Warning: NSObject <NSXMLParserDelegate>
#else
@interface Warning: NSObject
#endif
{
   // interface definition ...

我没有尝试使用4.0，但它适用于3.1和3.2之间的另一个例子

I didn't try this with 4.0, but it worked on another example between 3.1 and 3.2

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