如何從NSURL的末尾刪除3個字符？

Question

我的第一個問題！我已經能夠編寫大部分這個RSS閱讀器而無需獲得幫助（通過大量的搜索，通過計算器！），但我在這裏難倒了。

NSString *urlbase = [[NSString alloc] initWithFormat:[links3 objectAtIndex:indexPath.row]]; 
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlbase]]; 
NSCharacterSet *whitespaces = [NSCharacterSet whitespaceCharacterSet]; 
NSPredicate *noEmptyStrings = [NSPredicate predicateWithFormat:@"SELF != ''"]; 

NSArray *parts = [urlbase componentsSeparatedByCharactersInSet:whitespaces]; 
NSArray *filteredArray = [parts filteredArrayUsingPredicate:noEmptyStrings]; 
urlbase = [filteredArray componentsJoinedByString:@" "]; 

NSLog(@"%@ %i" , urlbase, 4353); 
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlbase]]; 

links3數組是帶字符串的NSMutableArray。前幾行完美地消除了從數組開始的每個字符串的空間，這些字符串存儲在'urlbase'中，因此當它們出來時它們看起來很好。當我們的NSLog urlbase，我們看到：

http://www.feedzilla.com/r/D7E6204FEDBFE541314B997AAB5D2DF9CBA2EFEE 

但是，當我們使用：[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlbase]]

我們看到：http://www.feedzilla.com/r/D7E6204FEDBFE541314B997AAB5D2DF9CBA2EFEE%0A

我該如何解決這個問題？我能否以某種方式移除這些尾巴元素？謝謝！

工作代碼：

NSMutableArray *links3 = [[NSMutableArray alloc] init]; 
RSSAppDelegate *appDelegate = (RSSAppDelegate *)[[UIApplication sharedApplication] delegate]; 
links3 = appDelegate.links; 
NSLog(@"%@ %i", [links3 objectAtIndex:indexPath.row], 3453); 
NSString *urlbase = [[NSString alloc] initWithFormat:[links3 objectAtIndex:indexPath.row]]; 
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlbase]]; 
NSCharacterSet *whitespaces = [NSCharacterSet whitespaceCharacterSet]; 
NSPredicate *noEmptyStrings = [NSPredicate predicateWithFormat:@"SELF != ''"]; 

NSArray *parts = [urlbase componentsSeparatedByCharactersInSet:whitespaces]; 
NSArray *filteredArray = [parts filteredArrayUsingPredicate:noEmptyStrings]; 
urlbase = [filteredArray componentsJoinedByString:@" "]; 

NSLog(@"%@ %i" , urlbase, 4353); 


NSLog(@"%@ %i" , urlbase, 345346); 
NSString* fixed = [urlbase stringByTrimmingCharactersInSet:[NSCharacterSet newlineCharacterSet]]; 

NSURL *hellothere = [NSURL URLWithString:fixed]; 
NSLog(@"%@ %i", hellothere, 54); 


    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:fixed]]; 

嘿，我並沒有說這是漂亮。感謝Diederik Hoogenboom！

Answer 1

試試這個：

[urlbase stringByTrimmingCharactersInSet:[NSCharacterSet newlineCharacterSet]] 

你的URL字符串的最後一部分是換行。