的Visual Basic。載有（）空異常

-1

  Dim words(0) As String 
      Dim trie As String 
      Dim temp As String 
      For i = 1 To 26 
       trie = encrypt(a, -i) 
       Console.WriteLine(trie) 
       For j = 0 To words.Length - 1 
        temp = words(j) 
        If trie.Contains(temp) Then 
         Console.ReadLine() 
        End If 
       Next 
      Next

應該檢查是否線索包含數組的話任何項目，但它拋出一個異常NULL。

encrypt(a, -i)只是改變字符串

來源

2016-12-06 Xain R

細節的缺乏。什麼是'了'？ –

什麼是例外？ –

['String.Contains']（https://msdn.microsoft.com/de-de/library/dy85x1sa（v = vs.110）.aspx）如果傳遞的參數是空引用，則會引發'ArgumentNullException'。所以你必須檢查它：'如果溫度不是Nothing並且trie.Contains（temp）Then ...' –

你必須檢查是否這些變量是空的字母：

Dim words(0) As String = String.Empty 
Dim trie As String = String.Empty 
Dim temp As String = String.Empty 

For i = 1 To 26 
    trie = encrypt(a, -i) 
    Console.WriteLine(trie) 
    For j = 0 To words.Length - 1 
     temp = words(j) 
     If Not temp Is Nothing AndAlso _ 
      Not trie Is Nothing AndAlso _ 
       trie.Contains(temp) Then 
       Console.ReadLine() 
     End If 
    Next 
Next

來源

2016-12-06 13:52:49 Yahfoufi

的Visual Basic。載有（）空異常

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