stringByReplacingCharactersInRange不替換它的追加！

Question

我花了5小時試圖找出一種方式，爲..我試圖做一個hang子手應用程序的iPhone和下面的方法是應該調用時，玩家選擇一個字符，它匹配所選單詞的方法。 。

-(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; 

}

問題stringByReplacingCharactersInRange不更換字符，它追加到下劃線我究竟做錯了什麼？

最好的問候， 中號Hegab

Answer 1

只是發揮各地與您的代碼。它不起作用，但stringByReplacingCharactersInRange不是你的問題。
你的遊戲邏輯不能像它應該那樣工作。拿一支筆和一張紙，然後「手動」循環遍歷你的for循環，看看這一定是錯誤的。
下一次，如果你盯着代碼半個小時，拿一支筆。這將爲您節省至少4個小時:-)

您的代碼存在一些問題。假設Kartoffelkäfer是您正在查找的單詞，並且用戶輸入了信函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;  
} 

我認爲hiddenText.text的內容是@ 「_ __ _ __ 」 和fullText.text的內容是@「 Kartoffelkäfer」。所以hiddentext和fullText的長度是一樣的。
我不得不改變得到這個工作：

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; 

從優秀碼遠的地方，但我試圖改變你的代碼儘可能少。