移動在C＃中的文本文件，如果它包含一個值

Question

我想，如果它包含特定字符串移動文件，代碼如下

foreach (FileInfo file in files) 
     { 
      //reads the file contents 

       string MessageContents = File.ReadAllText(file.FullName); 
       //checks if the textwords are present in the file 
       foreach (string Keyword in textwords) 
       { 
        //if they are file is moved to quarantine messages 
        if (MessageContents.Contains(Keyword)) 
        { 
         try 
         { 
          File.Move(file.FullName, File_quarantine); 
         } 
         catch (IOException cannot_Move_File) 
         { 
          MessageBox.Show("The process has failed: {0}", cannot_Move_File.ToString()); 
         } 
         break; 
        } 
         //else it is moved To valid messages 
        else 
        { 
         try 
         { 
          File.Move(file.FullName, File_Valid); 
         } 
         catch (IOException cannot_Move_File) 
         { 
          MessageBox.Show("The process has failed: {0}", cannot_Move_File.ToString()); 
         } 
         break; 
        } 
       } 
      } 
     } 

但過程總是失敗，錯誤A first chance exception of type 'System.IO.IOException' occurred in mscorlib.dll

我不確定爲什麼發生這種情況，任何幫助將不勝感激。

Answer 1

您仍然對該文件有鎖定，因爲您打開了一個流。移動文件移出文件讀數的邏輯。

這應該會產生所需的結果;

foreach (FileInfo file in files) 
{ 
    String messageContents = File.ReadAllText(file.FullName); 
    bool toQuarantine = textwords.Any(keyWord => messageContents.Contains(keyWord)); 

    try 
    { 
     File.Move(file.FullName, toQuarantine ? File_quarantine : File_Valid); 
    } 
    catch (IOException cannot_Move_File) 
    { 
     MessageBox.Show("The process has failed: {0}", cannot_Move_File.ToString()); 
    } 
} 

Answer 2

基本上你已經鎖定了文件。閱讀時無法移動它。

如果文件比較小，你可以使用這樣的技術：

String content = File.ReadAllText(filename); 

// at this point, the file is not locked, unlike the 
// way it is in your question. you are free to move it 

foreach (String keyword in keywords) { 
    if (content.Contains(keyword)) { 
     // Move file 
     break; 
    } 
}