在ios9中替换stringByAddingPercentEscapesUsingEncoding？

Question

在iOS8和之前我可以使用:

NSString *str = ...; // some URL
NSString *result = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

在iOS9中stringByAddingPercentEscapesUsingEncoding已被替换为stringByAddingPercentEncodingWithAllowedCharacters:

NSString *str = ...; // some URL
NSCharacterSet *set = ???; // where to find set for NSUTF8StringEncoding?
NSString *result = [str stringByAddingPercentEncodingWithAllowedCharacters:set];

我的问题是:在哪里找到所需的NSCharacterSet(NSUTF8StringEncoding)以便正确更换stringByAddingPercentEscapesUsingEncoding？

Answer 1

弃用消息说(强调我的):

请改为使用stringByAddingPercentEncodingWithAllowedCharacters(_ :),它始终使用推荐的UTF-8编码,并对特定的URL组件或子组件进行编码,因为每个URL组件或子组件对于哪些字符有效具有不同的规则.

所以你只需要提供足够NSCharacterSet的参数.幸运的是,对于URL,有一个非常方便的类方法URLHostAllowedCharacterSet,你可以像这样使用:

let encodedHost = unencodedHost.stringByAddingPercentEncodingWithAllowedCharacters(.URLHostAllowedCharacterSet())

更新Swift 3 - 该方法成为静态属性urlHostAllowed:

let encodedHost = unencodedHost.addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)

但请注意:

此方法旨在对URL组件或子组件字符串进行百分比编码,而不是对整个URL字符串进行编码.

Answer 2

对于Objective-C:

NSString *str = ...; // some URL
NSCharacterSet *set = [NSCharacterSet URLHostAllowedCharacterSet]; 
NSString *result = [str stringByAddingPercentEncodingWithAllowedCharacters:set];

在哪里可以找到NSUTF8StringEncoding的集合？

六个URL组件和子组件有预定义的字符集,允许百分比编码.这些字符集传递给 -stringByAddingPercentEncodingWithAllowedCharacters:.

 // Predefined character sets for the six URL components and subcomponents which allow percent encoding. These character sets are passed to -stringByAddingPercentEncodingWithAllowedCharacters:.
@interface NSCharacterSet (NSURLUtilities)
+ (NSCharacterSet *)URLUserAllowedCharacterSet;
+ (NSCharacterSet *)URLPasswordAllowedCharacterSet;
+ (NSCharacterSet *)URLHostAllowedCharacterSet;
+ (NSCharacterSet *)URLPathAllowedCharacterSet;
+ (NSCharacterSet *)URLQueryAllowedCharacterSet;
+ (NSCharacterSet *)URLFragmentAllowedCharacterSet;
@end

弃用消息说(强调我的):

请改为使用stringByAddingPercentEncodingWithAllowedCharacters(_ :),它始终使用推荐的UTF-8编码,并对特定的URL组件或子组件进行编码,因为每个URL组件或子组件对于哪些字符有效具有不同的规则.

所以你只需要提供足够NSCharacterSet的参数.幸运的是,对于URL,有一个非常方便的类方法URLHostAllowedCharacterSet,你可以像这样使用:

NSCharacterSet *set = [NSCharacterSet URLHostAllowedCharacterSet]; 

但请注意:

此方法旨在对URL组件或子组件字符串进行百分比编码,而不是对整个URL字符串进行编码.

Answer 3

URLHostAllowedCharacterSet是不工作对我来说.我URLFragmentAllowedCharacterSet改用了.

目标-C

NSCharacterSet *set = [NSCharacterSet URLFragmentAllowedCharacterSet];
NSString * encodedString = [@"url string" stringByAddingPercentEncodingWithAllowedCharacters:set];

SWIFT - 4

"url string".addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)

以下是有用的(反向)字符集:

URLFragmentAllowedCharacterSet  "#%<>[\]^`{|}
URLHostAllowedCharacterSet      "#%/<>?@\^`{|}
URLPasswordAllowedCharacterSet  "#%/:<>?@[\]^`{|}
URLPathAllowedCharacterSet      "#%;<>?[\]^`{|}
URLQueryAllowedCharacterSet     "#%<>[\]^`{|}
URLUserAllowedCharacterSet      "#%/:<>?@[\]^`

Answer 4

Objective-C的

这段代码对我有用:

urlString = [urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLFragmentAllowedCharacterSet]];