iOS 5:使 NSString 类别包括 NSCFConstantString?

问题描述

我有一个 NSString 类别类 (NSString+URLEncoding.h).我遇到了未知的选择器崩溃，因为我调用类别方法的字符串已被 iOS 优化为 NSCFConstantString.

I have an NSString category class (NSString+URLEncoding.h). I am running into and unknown selector crash, because the string I am calling the category method has been optimized into an NSCFConstantString by iOS.

-[__NSCFConstantString URLEncodedString]: unrecognized selector sent to instance 0x290174

我从以下方面了解到 iOS 5 中的 NSCFConstantString 与 NSCFString 优化:http://www.cocoanetics.com/2012/03/beware-of-nsstring-optimizations/

I learned of the NSCFConstantString vs. NSCFString optimizations in iOS 5 from: http://www.cocoanetics.com/2012/03/beware-of-nsstring-optimizations/

有谁知道我如何让 NSString 类别包含常量字符串，甚至强制 var 成为 NSString/NSCFString 而不是 NSCFConstantString?

Is anyone aware of how I can get the NSString category to include the Constant strings or even force the var to be an NSString/NSCFString and not an NSCFConstantString?

干杯，Z

-编辑-

• 链接器标志 -ObjC -all_load 都已实现
• NSString+URLEncoding.m 包含在目标编译源中
• NSString+URLEncoding.m 实现了 URLEncodedString 方法.
• 检查是否有僵尸.

我正在向 ShareKit 2.0 添加共享服务

I am adding a sharing service to ShareKit 2.0

标题:

@interface NSString (OAURLEncodingAdditions)

- (NSString *)URLEncodedString;

实现:

@implementation NSString (OAURLEncodingAdditions)

- (NSString *)URLEncodedString 
{
    NSString *result = (NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
                                                                           (CFStringRef)self,
                                                                           NULL,
                                                                           CFSTR("!*'();:@&=+$,/?%#[]"),
                                                                           kCFStringEncodingUTF8);
    [result autorelease];
    return result;
}

推荐答案

链接器存在问题，可能导致其死代码剥离完全忽略任何仅包含 obj-c 类别(或以其他方式未引用)的目标文件).理论上将 -ObjC 标志传递给链接器应该可以解决这个问题，但这似乎并不总是有效.您可以通过提供 -all_load 链接器标志来解决此问题，这将导致链接器始终链接所有目标文件.

There's an issue with the linker that can cause its dead-code stripping to completely omit any object files that only contain obj-c categories (or that are otherwise unreferenced). Theoretically passing the -ObjC flag to the linker should fix this, but that doesn't seem to always work. You can work around this issue by providing the -all_load linker flag, which will cause the linker to always link in all object files.

请注意，如果您的类别是您在某处包含的子项目或库的一部分，您可能必须在父项目上设置 -all_load.

Note that you might have to set -all_load on the parent project if your category is part of a sub-project or library that you-re including somewhere.

更新:我相信 -ObjC 现在是可靠的，并且多年来一直如此，因此您可以停止使用 -all_load 来解决这个问题.

Update: I believe -ObjC is reliable now and has been for years so you can stop using -all_load for this issue.

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