簡化的邏輯，以避免重複錯誤信息

Question

到目前爲止，我有以下幾點：

// Gets all the drives 
DriveInfo[] allDrives = DriveInfo.GetDrives(); 

// checks if any CD-Rom exists in the drives 
var cdRomExists = allDrives.Any(x => x.DriveType == DriveType.CDRom); 

// Get all the cd roms 
var cdRoms = allDrives.Where(x=>x.DriveType==DriveType.CDRom); 

if (cdRomExists.Equals(true)) 
{ 
    // Loop through the cd roms collection 
    foreach(var cdRom in cdRoms) 
    { 
     Console.WriteLine("Drive {0}", cdRom.Name); 
     Console.WriteLine(" File type: {0}", cdRom.DriveType); 

     if (cdRom.IsReady == true) 
     { 
      if (cdRom.DriveType == DriveType.CDRom) 
      { 
       DirectoryInfo di = new DirectoryInfo(cdRom.RootDirectory.Name); 

       var file = di.GetFiles("*.csv", SearchOption.AllDirectories).FirstOrDefault(); 

       if (file == null) 
       { 
        errorwindow.Message = LanguageResources.Resource.File_Not_Found; 
        dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
       } 
       else 
       { 
        foreach (FileInfo info in di.GetFiles("*.csv", SearchOption.AllDirectories)) 
        { 
         Debug.Print(info.FullName); 
         ImportCSV(info.FullName); 
         break;  // only looking for the first one 
        } 
       } 
      } 
     } 
     else if (cdRom.IsReady == false) 
     { 
      errorwindow.Message = LanguageResources.Resource.CDRom_Not_Ready; 
      dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow);    
     } 
    } 
} 
else 
{ 
    errorwindow.Message = LanguageResources.Resource.CDRom_Error; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
} 

有以下的問題，錯誤消息連續彈出兩次，表示如果沒有CD-ROM中驅動器，因爲我的電腦同時包含DVD和藍光驅動器。如果有一個包含CSV文件的CD Rom，它會成功導入，但由於運行到藍光驅動器的foreach循環會彈出另一條消息，並彈出。

我只想顯示一個錯誤消息，對於這些情況： - 如果沒有光盤是準備幷包含在驅動 - 如果光驅CSV不包含CSV

我認爲我的邏輯過於複雜，我需要幫助調整我的邏輯陳述。

Answer 1

你只需要跟蹤至少一個的驅動器爲你工作。如果他們都沒有，那麼你想輸出錯誤信息。還有其他一些你可以做的事情（不需要做Any/Where，不需要做.Equals(true)等等。更具體地說，不需要持續檢查它是否是正確的驅動器。cdRoms集合將只包含驅動器用正確的類型，因爲這是你在Where子句指定哪些

// Gets all the drives 
DriveInfo[] allDrives = DriveInfo.GetDrives(); 

// Get all the cd roms 
var cdRoms = allDrives.Where(x=>x.DriveType==DriveType.CDRom); 

if (cdRoms.Count() > 0) 
{ 
    bool found = false; 
    // Loop through the cd roms collection 
    foreach(var cdRom in cdRoms) 
    { 
     Console.WriteLine("Drive {0}", cdRom.Name); 
     Console.WriteLine(" File type: {0}", cdRom.DriveType); 

     if (cdRom.IsReady == true) 
     { 
      DirectoryInfo di = new DirectoryInfo(cdRom.RootDirectory.Name); 

      var file = di.GetFiles("*.csv", SearchOption.AllDirectories).FirstOrDefault(); 

      if (file == null) 
      { 
       errorwindow.Message = LanguageResources.Resource.File_Not_Found; 
       dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
      } 
      else 
      { 
       foreach (FileInfo info in di.GetFiles("*.csv", SearchOption.AllDirectories)) 
       { 
        Debug.Print(info.FullName); 
        ImportCSV(info.FullName); 
        found = true; 
        break;  // only looking for the first one 
       } 
      } 
     } 
     else 
     { 
      Debug.Print(string.Format("Drive {0} is not ready", cdRom.Name)); 

     } 
    } 
    if (!found) 
    { 
     errorwindow.Message = LanguageResources.Resource.CDRom_Not_Ready; 
     dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow);    
    } 
} 
else 
{ 
    errorwindow.Message = LanguageResources.Resource.CDRom_Error; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
} 

Answer 2

你的代碼可以改寫爲以下幾點：

var cdRoms = allDrives.Where(x => x.DriveType == DriveType.CDRom && x.IsReady); 

if (cdRoms.Any()) 
{ 
    foreach(var cdRom in cdRoms) 
    { 
     Console.WriteLine("Drive {0}", cdRom.Name); 
     Console.WriteLine(" File type: {0}", cdRom.DriveType); 

     var di = new DirectoryInfo(cdRom.RootDirectory.Name); 
     var file = di.GetFiles("*.csv", SearchOption.AllDirectories).FirstOrDefault(); 

     if (file == null) 
     { 
      errorwindow.Message = LanguageResources.Resource.File_Not_Found; 
      dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
     } 
     else 
     { 
      foreach (var info in di.GetFiles("*.csv", SearchOption.AllDirectories)) 
      { 
       Debug.Print(info.FullName); 
       ImportCSV(info.FullName); 
       break; 
      } 
     } 
    } 
} 
else 
{ 
    errorwindow.Message = LanguageResources.Resource.CDRom_Error; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
} 

變化：

• 沒有必要使用Where和Any像你這樣，從所有驅動器過濾CD-ROM驅動器，看看是否存在任何
• 只能選擇驅動器是是 CD-ROM驅動器和準備
• 使用var如果可能的話，讓編譯器做的工作

Answer 3

這是我的做法，您的問題：

bool anyCdrom = false; 
bool anyReady = false; 
bool fileFound = false; 

// Loop through the cd roms collection 
foreach(var cdRom in DriveInfo.GetDrives().Where(drive => drive.DriveType == DriveType.CDRom)) 
{ 
    anyCdrom = true; 
    Console.WriteLine("Drive {0}", cdRom.Name); 
    Console.WriteLine(" File type: {0}", cdRom.DriveType); 
    if (cdRom.IsReady) // You may want to put in into the intial where 
    { 
     anyReady = true;   
     foreach (string file in Directory.EnumerateFiles(cdRom.RootDirectory.Name, "*.csv", SearchOption.AllDirectories)) 
     { 
      fileFound = true; 
      Debug.Print(file); 
      ImportCSV(file); 
      break;  // only looking for the first one 
     } 
     if(fileFound) 
      break;          
    }  
} 

if(!anyCdrom) 
{ 
    errorwindow.Message = LanguageResources.Resource.CDRom_Error; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
} 
else if(!anyReady) 
{ 
    errorwindow.Message = LanguageResources.Resource.CDRom_Not_Ready; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow);      
} 
else if(!fileFound) 
{ 
    errorwindow.Message = LanguageResources.Resource.File_Not_Found; 
    dialogService.ShowDialog(LanguageResources.Resource.Error, errorWindow); 
} 

它只打印時出現錯誤：

1. 沒有光驅
2. 沒有光驅準備
3. 存在任何現成光盤