.net core 讀取本地指定目錄下的文件的實(shí)例代碼

更新時(shí)間：2018年09月16日 09:43:38 作者：蝸牛丨

這篇文章主要介紹了.net core 讀取本地指定目錄下的文件的實(shí)例代碼，非常不錯(cuò)，具有一定的參考借鑒價(jià)值 ,需要的朋友可以參考下

項(xiàng)目需求

asp.net core 讀取log目錄下的.log文件，.log文件的內(nèi)容如下：

xxx.log

------------------------------------------begin---------------------------------
寫入時(shí)間:2018-09-11 17:01:48
userid=1000
golds=10
-------------------------------------------end---------------------------------

一個(gè) begin end 為一組，同一個(gè).log文件里 userid 相同的，取寫入時(shí)間最大一組值，所需結(jié)果如下：

UserID   Golds   RecordDate
1001     20     2018/9/11 17:10:48
1000     20     2018/9/11 17:11:48
1003     30     2018/9/11 17:12:48
1002     10     2018/9/11 18:01:48
1001     20     2018/9/12 17:10:48
1000     30     2018/9/12 17:12:48
1002     10     2018/9/12 18:01:48

項(xiàng)目結(jié)構(gòu)

Snai.File.FileOperation Asp.net core 2.0 網(wǎng)站

項(xiàng)目實(shí)現(xiàn)

新建Snai.File解決方案，在解決方案下新建一個(gè)名Snai.File.FileOperation Asp.net core 2.0 空網(wǎng)站

把log日志文件拷備到項(xiàng)目下

修改Startup類的ConfigureServices()方法，注冊(cè)訪問本地文件所需的服務(wù)，到時(shí)在中間件中通過構(gòu)造函數(shù)注入添加到中間件，這樣就可以在一個(gè)地方控制文件的訪問路徑（也就是應(yīng)用程序啟動(dòng)的時(shí)候）

public void ConfigureServices(IServiceCollection services)
{
　　services.AddSingleton<IFileProvider>(new PhysicalFileProvider(Directory.GetCurrentDirectory()));
}

新建 Middleware 文件夾，在 Middleware下新建 Entity 文件夾，新建 UserGolds.cs 類，用來(lái)保存讀取的日志內(nèi)容，代碼如下

namespace Snai.File.FileOperation.Middleware.Entity
{
 public class UserGolds
 {
  public UserGolds()
  {
   RecordDate = new DateTime(1970, 01, 01);
   UserID = 0;
   Golds = 0;
  }
  public DateTime RecordDate { get; set; }
  public int UserID { get; set; }
  public int Golds { get; set; }
 }
}

在 Middleware 下新建 FileProviderMiddleware.cs 中間件類，用于讀取 log 下所有日志文件內(nèi)容，并整理成所需的內(nèi)容格式，代碼如下

namespace Snai.File.FileOperation.Middleware
{
 public class FileProviderMiddleware
 {
  private readonly RequestDelegate _next;
  private readonly IFileProvider _fileProvider;
  public FileProviderMiddleware(RequestDelegate next, IFileProvider fileProvider)
  {
   _next = next;
   _fileProvider = fileProvider;
  }
  public async Task Invoke(HttpContext context)
  {
   var output = new StringBuilder("");
   //ResolveDirectory(output, "", "");
   ResolveFileInfo(output, "log", ".log");
   await context.Response.WriteAsync(output.ToString());
  }
  //讀取目錄下所有文件內(nèi)容
  private void ResolveFileInfo(StringBuilder output, string path, string suffix)
  {
   output.AppendLine("UserID Golds RecordDate");
   IDirectoryContents dir = _fileProvider.GetDirectoryContents(path);
   foreach (IFileInfo item in dir)
   {
    if (item.IsDirectory)
    {
     ResolveFileInfo(output,
      item.PhysicalPath.Substring(Directory.GetCurrentDirectory().Length),
      suffix);
    }
    else
    {
     if (item.Name.Contains(suffix))
     {
      var userList = new List<UserGolds>();
      var user = new UserGolds();
      IFileInfo file = _fileProvider.GetFileInfo(path + "\\" + item.Name);
      using (var stream = file.CreateReadStream())
      {
       using (var reader = new StreamReader(stream))
       {
        string content = reader.ReadLine();
        while (content != null)
        {
         if (content.Contains("begin"))
         {
          user = new UserGolds();
         }
         if (content.Contains("寫入時(shí)間"))
         {
          DateTime recordDate;
          string strRecordDate = content.Substring(content.IndexOf(":") + 1).Trim();
          if (DateTime.TryParse(strRecordDate, out recordDate))
          {
           user.RecordDate = recordDate;
          }
         }
         if (content.Contains("userid"))
         {
          int userID;
          string strUserID = content.Substring(content.LastIndexOf("=") + 1).Trim();
          if (int.TryParse(strUserID, out userID))
          {
           user.UserID = userID;
          }
         }
         if (content.Contains("golds"))
         {
          int golds;
          string strGolds = content.Substring(content.LastIndexOf("=") + 1).Trim();
          if (int.TryParse(strGolds, out golds))
          {
           user.Golds = golds;
          }
         }
         if (content.Contains("end"))
         {
          var userMax = userList.FirstOrDefault(u => u.UserID == user.UserID);
          if (userMax == null || userMax.UserID <= 0)
          {
           userList.Add(user);
          }
          else if (userMax.RecordDate < user.RecordDate)
          {
           userList.Remove(userMax);
           userList.Add(user);
          }
         }
         content = reader.ReadLine();
        }
       }
      }
      if (userList != null && userList.Count > 0)
      {
       foreach (var golds in userList.OrderBy(u => u.RecordDate))
       {
        output.AppendLine(golds.UserID.ToString() + " " + golds.Golds + " " + golds.RecordDate);
       }
       output.AppendLine("");
      }
     }
    }
   }
  }
  //讀取目錄下所有文件名
  private void ResolveDirectory(StringBuilder output, string path, string prefix)
  {
   IDirectoryContents dir = _fileProvider.GetDirectoryContents(path);
   foreach (IFileInfo item in dir)
   {
    if (item.IsDirectory)
    {
     output.AppendLine(prefix + "[" + item.Name + "]");
     ResolveDirectory(output,
      item.PhysicalPath.Substring(Directory.GetCurrentDirectory().Length),
      prefix + " ");
    }
    else
    {
     output.AppendLine(path + prefix + item.Name);
    }
   }
  }
 }
 public static class UseFileProviderExtensions
 {
  public static IApplicationBuilder UseFileProvider(this IApplicationBuilder app)
  {
   return app.UseMiddleware<FileProviderMiddleware>();
  }
 }
}

上面有兩個(gè)方法 ResolveFileInfo()和ResolveDirectory()

ResolveFileInfo() 讀取目錄下所有文件內(nèi)容，也就是需求所用的方法

ResolveDirectory() 讀取目錄下所有文件名，是輸出目錄下所有目錄和文件名，不是需求所需但也可以用

修改Startup類的Configure()方法，在app管道中使用文件中間件服務(wù)

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
　　if (env.IsDevelopment())
　　{
　　　　app.UseDeveloperExceptionPage();
　　}

　　app.UseFileProvider();
　　
　　app.Run(async (context) =>
　　{
　　　　await context.Response.WriteAsync("Hello World!");
　　});
}

到此所有代碼都已編寫完成

啟動(dòng)運(yùn)行項(xiàng)目，得到所需結(jié)果，頁(yè)面結(jié)果如下