stringByReplacingCharactersInRange不替换它的追加！

Question

我花了5小时试图找出一种方式，为..我试图做一个hang子手应用程序的iPhone和下面的方法是应该调用时，玩家选择一个字符，它匹配所选单词的方法。 。

-(void)replaceTheHiddenTextWithNewText:(NSString*)character{ 
NSString *fullTextField = fullText.text; 
int textCount = [hiddenText.text length]; 

NSString *theRiddle; 
for (int i = textCount-1 ; i>=0; i--) { 

    NSString *hiddenTextField = [[NSMutableString alloc] initWithString:hiddenText.text]; 
    NSString *aChar=[fullTextField substringWithRange:NSMakeRange(i/3,1)]; 

    if ([aChar isEqualToString:@" "]) { 

     theRiddle= [hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:@" "]; 
    }else if ([aChar isEqualToString:character]) { 
     theRiddle =[hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:aChar]; 

     }else{ 
     theRiddle = [hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:@"_"]; 


    } 
    hiddenTextField = theRiddle;  
} 
hiddenText.text=theRiddle; 

}

问题stringByReplacingCharactersInRange不更换字符，它追加到下划线我究竟做错了什么？

最好的问候， 中号Hegab

Answer 1

只是发挥各地与您的代码。它不起作用，但stringByReplacingCharactersInRange不是你的问题。
你的游戏逻辑不能像它应该那样工作。拿一支笔和一张纸，然后“手动”循环遍历你的for循环，看看这一定是错误的。
下一次，如果你盯着代码半个小时，拿一支笔。这将为您节省至少4个小时:-)

您的代码存在一些问题。假设Kartoffelkäfer是您正在查找的单词，并且用户输入了信函f。

for (int i = textCount-1 ; i>=0; i--) { 
    NSString *hiddenTextField = [[NSMutableString alloc] initWithString:hiddenText.text]; 
    // you are creating this string in every loop from the text of a (I guess) UITextField. 
    // I don't know what the content of this text is but I guess it is suppossed to be `______________` 
    // in every loop you replace the word where you replaced the _ with the correct letter with the string from the textfield. 
    // Btw, you are leaking this string. 

    NSString *aChar=[fullTextField substringWithRange:NSMakeRange(i/3,1)]; 
    // Kartoffelkäfer has 14 chars so i is 13. And 13/3 is 4. And the character at index 4 is o 
    // In the next loop i is 12. And 12/3 is 4, too. 
    // next three loops will give you index 3. Then you get three times index 2, and so one. 
    // you never reach the letter f, anyway. 

    if ([aChar isEqualToString:@" "]) { 
     theRiddle= [hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:@" "]; 
    }else if ([aChar isEqualToString:character]) { 
     theRiddle =[hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:aChar]; 
     }else{ 
     theRiddle = [hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:@"_"]; 
    // You should not replace a unmatched character with a _ . Because already matched letters would be overwritten. 

    } 
    hiddenTextField = theRiddle;  
} 

我认为hiddenText.text的内容是@ “_ __ _ __ ” 和fullText.text的内容是@“ Kartoffelkäfer”。所以hiddentext和fullText的长度是一样的。
我不得不改变得到这个工作：

NSString *theRiddle; 
NSString *hiddenTextField = [[[NSMutableString alloc] initWithString:hiddenText.text] autorelease]; 
for (int i = textCount-1 ; i>=0; i--) { 
    NSString *aChar=[fullTextField substringWithRange:NSMakeRange(i,1)]; 
    if ([aChar isEqualToString:@" "]) { 
     theRiddle= [hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:@" "]; 
    }else if ([aChar isEqualToString:character]) { 
     theRiddle =[hiddenTextField stringByReplacingCharactersInRange:NSMakeRange(i, 1) withString:aChar]; 
    } 
    else { 
     theRiddle = hiddenTextField; 
    } 
    hiddenTextField = theRiddle;  
} 
hiddenText.text=theRiddle; 

从优秀码远的地方，但我试图改变你的代码尽可能少。