錯誤：「未將對象引用設置爲對象的實例」

Question

這是我的代碼。我知道這個錯誤很常見，但我仍然無法弄清楚爲什麼會出現這個錯誤。我試圖從樂器陣列中的單詞中刪除元音。我做了一個If語句來確保錯誤不是由Instrument [a]爲空造成的。

 string[] Instruments = new String[7]; 
     Instruments[0] = "hej"; 
     Instruments[1] = "cello"; 
     Instruments[2] = "guitar"; 
     Instruments[3] = "violin"; 
     Instruments[4] = "double bass"; 
     Instruments[5] = "drums"; 

     string[] Vowels = new String[9]; 
     Vowels[0] = "e"; 
     Vowels[1] = "y"; 
     Vowels[2] = "u"; 
     Vowels[3] = "i"; 
     Vowels[4] = "o"; 
     Vowels[5] = "å"; 
     Vowels[6] = "a"; 
     Vowels[7] = "æ"; 
     Vowels[8] = "ø"; 

     string message = "start: "; 

     for (int a = 0; a < Instruments.Length; a++) 
     { 

      string InstrumentCurrent = Instruments[a]; 
      Console.WriteLine(Instruments[a]); 
       for (int i = 0; i < Vowels.Length; i++) 
       { 
        if (InstrumentCurrent != null); 
        { 
        //InstrurmentCurrent = InstrumentCurrent += ""; (If I uncomment this, the code works fine) 
        InstrumentCurrent = InstrumentCurrent.Replace(Vowels[i], ""); 
        } 

       } 
       message += InstrumentCurrent; 
       message += ", "; 

     } 

     MessageBox.Show(message); 

Answer 1

你的問題是非常非常有趣的 - 看看這個行：

if (InstrumentCurrent != null); 

刪除在最後的分號，然後再試一次。