如何修剪到NSString中的URL？

Question

在调试时，我以这种方式获得了url：

myURL   __NSCFString *  @"(\n    "http://www.worldweatheronline.com/images/wsymbols01_png_64/wsymbol_0003_white_cloud.png"\n)"  0x0a8a3510

我试图通过方法将(\\n和\\n)替换为""

tringByReplacingOccurrencesOfString:@" (\n " withString:@""

终于我以这种方式获得了我的网址

myURL   __NSCFString *  @"   "http://www.worldweatheronline.com/images/wsymbols01_png_64/wsymbol_0003_white_cloud.png"" 0x08c12540

但是我想要的是

myURL   __NSCFString *  @"http://www.worldweatheronline.com/images/wsymbols01_png_64/wsymbol_0003_white_cloud.png"  0x08c12540

有什么好的方法可以帮助我获得想要的字符串？

Answer 1

这应该从字符串的末尾修剪非URL字符，并加上括号字符：

NSMutableCharacterSet* urlSet = [[NSMutableCharacterSet alloc] init];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLUserAllowedCharacterSet]];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLPasswordAllowedCharacterSet]];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLHostAllowedCharacterSet]];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLPathAllowedCharacterSet]];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLQueryAllowedCharacterSet]];
urlSet = [urlSet formUnionWithCharacterSet:[NSCharacterSet URLFragmentAllowedCharacterSet]];
urlSet = [[urlSet invertedSet] mutableCopy];
[urlSet addCharactersInString:@"()"];

myURL = [myURL stringByTrimmingCharactersInSet:urlSet];

如果实际上是反斜杠+ n而不是换行符，则可能需要在去除“ \\ n”之后执行此操作。