問題描述

我有一個 NSString 類別類 (NSString+URLEncoding.h).我遇到了未知的選擇器崩潰，因為我調用類別方法的字符串已被 iOS 優化為 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

我從以下方面了解到 iOS 5 中的 NSCFConstantString 與 NSCFString 優化: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/

有誰知道我如何讓 NSString 類別包含常量字符串，甚至強制 var 成為 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

-編輯-

• 鏈接器標志 -ObjC -all_load 都已實現
• NSString+URLEncoding.m 包含在目標編譯源中
• NSString+URLEncoding.m 實現了 URLEncodedString 方法.
• 檢查是否有僵尸.

我正在向 ShareKit 2.0 添加共享服務

I am adding a sharing service to ShareKit 2.0

標題:

@interface NSString (OAURLEncodingAdditions)

- (NSString *)URLEncodedString;

實現:

@implementation NSString (OAURLEncodingAdditions)

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

推薦答案

鏈接器存在問題，可能導致其死代碼剝離完全忽略任何僅包含 obj-c 類別(或以其他方式未引用)的目標文件).理論上將 -ObjC 標志傳遞給鏈接器應該可以解決這個問題，但這似乎并不總是有效.您可以通過提供 -all_load 鏈接器標志來解決此問題，這將導致鏈接器始終鏈接所有目標文件.

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.

請注意，如果您的類別是您在某處包含的子項目或庫的一部分，您可能必須在父項目上設置 -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 現在是可靠的，并且多年來一直如此，因此您可以停止使用 -all_load 來解決這個問題.

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

這篇關于iOS 5:使 NSString 類別包括 NSCFConstantString?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！