最好的办法让只有某些集团一个字符串

Question

我正在使用下面的代码文件名列表的：

 //Set up Datatable 
     dtUpgradeFileInfo.Columns.Add("BaseFW"); 
     dtUpgradeFileInfo.Columns.Add("ActiveFW"); 
     dtUpgradeFileInfo.Columns.Add("UpgradeFW"); 
     dtUpgradeFileInfo.Columns.Add("FileName"); 

     //Gets Upgrade information and upgrade Files from Upgrade Folder 
     DirectoryInfo di = new DirectoryInfo(g_strAppPath + "\\Update Files"); 
     FileInfo[] rgFiles = di.GetFiles("*.txt"); 
     foreach (FileInfo fi in rgFiles) 
     { 
      test1 = fi.Name.ToString(); 


     } 

所有文件名会在形式BXXXX_AXXXX_UXXXX。当然，X代表0-9的数字，我需要这3组数字来将每个数据放到数据表的相应列中。我最初打算获得代表每个分组的字符，并将它们组合在一起，但是我想知道是否有比将它发送给charArray更好的方法/更快的方法。有什么建议么？

Answer 1

这里是一个相对简单的方式来获得号码的开出TEST1（不含LINQ）：

... 
string test1 = fi.Name.ToString(); 

int baseFW=0; 
int activeFW=0; 
int upgradeFW=0; 

// Break the file name into the three groups 
string[] groups=test1.Split('_'); 

if (groups.Length==3) 
{ 
    // Create a numbers array to hold the numbers 
    int[] nums=new int[groups.Length]; 

    // Parse the numbers out of the strings 
    int idx=0; 
    foreach (string s in groups) 
    nums[idx++]=int.Parse(s.Remove(0,1)); // Convert to num 

    baseFW=nums[0]; 
    activeFW=nums[1]; 
    upgradeFW=nums[2]; 
} 
else 
{ 
    // Error handling... 
} 

如果你想做到这一点使用LINQ，那就更简单了：

... 
string test1 = fi.Name.ToString(); 

int baseFW=0; 
int activeFW=0; 
int upgradeFW=0; 

// Extract all numbers 
int[] nums=test1.Split('_') // Split on underscores 
       .Select(s => int.Parse(s.Remove(0,1))) // Convert to ints 
       .ToArray(); // For random access, below 

if (nums.Length==3) 
{ 
    baseFW=nums[0]; 
    activeFW=nums[1]; 
    upgradeFW=nums[2]; 
} 
else 
{ 
    // Error handling... 
} 

Answer 2

使用正则表达式允许您轻松解析出所需的值，并且还具有允许跳过目录中不匹配预期文件名格式的文件的额外好处。

您的代码将是这个样子：

 //Gets Upgrade information and upgrade Files from Upgrade Folder 
     string strRegex = @"^B(?<Base>[0-9]{4})_A(?<Active>[0-9]{4})_U(?<Upgrade>[0-9]{4}).txt$"; 
     RegexOptions myRegexOptions = RegexOptions.ExplicitCapture | RegexOptions.Compiled; 
     Regex myRegex = new Regex(strRegex, myRegexOptions); 

     DirectoryInfo di = new DirectoryInfo(g_strAppPath + "\\Update Files"); 
     FileInfo[] rgFiles = di.GetFiles("*.txt"); 
     foreach (FileInfo fi in rgFiles) 
     { 
      string name = fi.Name.ToString(); 
      Match matched = myRegex.Match(name); 
      if (matched.Success) 
      { 
       //do the inserts into the data table here 
       string baseFw = matched.Groups["Base"].Value; 
       string activeFw = matched.Groups["Active"].Value; 
       string upgradeFw = matched.Groups["Upgrade"].Value; 
      } 
     }