未將對象引用設置爲對象的實例。 BitShuva

嗨，我已經下載了一些源代碼，並且我在開箱時遇到了一些重大問題。我一直無法從開發人員那裏得到答案，我也沒有看到其他人提出這個問題，但我看了看，看了看，我不知道發生了什麼問題。未將對象引用設置爲對象的實例。 BitShuva

我不斷收到此錯誤：

Server Error in '/' Application.
Object reference not set to an instance of an object.

說明：

An unhandled exception occurred during the execution of the current web request.
Please review the stack trace for more information about the error and where it originated in the code.

異常詳細信息：

System.NullReferenceException: Object reference not set to an instance of an object.

源錯誤：

Line 157:   // Expected ID is standard Raven ID: "songs/4321" 
Line 158:   const string expectedIdPrefix = "songs/"; 
Line 159:   if (song.Id.StartsWith(expectedIdPrefix, StringComparison.OrdinalIgnoreCase)) 
Line 160:   { 
Line 161:    throw new ArgumentException("ID wasn't in the expected format.");

Visual Studio強調了這一點代碼。（用** **表示）

using (var session = Get.A<IDocumentStore>().OpenSession()) 
     { 
      var songFiles = Directory 
       .EnumerateFiles(Server.MapPath("~/content/sample/music"), "*.mp3") 
       .Select(f => new 
       { 
        Song = new Song(Path.GetFileName(f)), 
        FilePath = f 
       }) 
       .ToArray(); 

       songFiles.ForEach(async f => **await f.Song.UploadMp3ToCdn(f.FilePath));** 

      if (!session.Query<Song>().Any()) 
      { 
       songFiles.ForEach(s => session.Store(s)); 

       session.SaveChanges(); 
      } 
     }

來源

2013-06-21 user1760784

是你的查詢var songFiles = ...正在返回一些東西。你是否驗證過songFiles不爲空？ – Guanxi