C# 本地图片缓存器ImageFileCache (www.csframework.com)

  C# 本地图片缓存器ImageFileCache (www.csframework.com)

C# Code:

/// <summary>
/// C# 本地图片缓存器(www.csframework.com)
/// </summary>
public class ImageFileCache
{
  //考虑异步应用，加锁
   private object _Locker = new object();
  
  //图片根目录
   private string _baseFolder = "";
  
  //图片数据库
   private DataTable _Data;
  
  /// <summary>
  /// 构造器
  /// </summary>
   public ImageFileCache(string baseFolder = "")
  {
    //默认为应用程序目录下
     if (String.IsNullOrWhiteSpace(baseFolder))
    baseFolder = Path.Combine(Application.StartupPath, "ImageCache");
    
    _baseFolder = baseFolder;
    
    if (!Directory.Exists(baseFolder))
    Directory.CreateDirectory(baseFolder);
    
    //加载数据库
     _Data = ReadDatabase();
  }
  
  #region Instance
  
  static ImageFileCache _Instance = null;
  
  public static ImageFileCache Instance
  {
    get
    {
      if (_Instance == null) _Instance = new ImageFileCache();
      return _Instance;
    }
  }
  
  #endregion;
  
  internal bool Exists(ImageBuckleName buckle, string url)
  {
    url = ToMD5(url);
    
    lock (_Locker)
    {
      return _Data.Select($"buckle='{buckle.ToString()}' AND url='{url}'").Length > 0;
    }
  }
  
  /// <summary>
  /// 数据库文件路径
  /// </summary>
   private string dbFile { get { return Path.Combine(_baseFolder, "cache_files.db"); } }
  
  /// <summary>
  /// 加载数据库
  /// </summary>
  /// <returns></returns>
   private DataTable ReadDatabase()
  {
    lock (_Locker)
    {
      string path = this.dbFile;
      
      if (File.Exists(path))
      {
        _Data = GetFileTable();
        _Data.ReadXml(path);
        return _Data;
      }
      else
      {
        _Data = GetFileTable();
        return _Data;
      }
    }
  }
  
  /// <summary>
  /// 保存数据库
  /// </summary>
   public void Save()
  {
    lock (_Locker)
    {
      _Data.WriteXml(this.dbFile, true);
    }
  }
  
  /// <summary>
  /// 获取图片
  /// </summary>
  /// <param name="buckle"></param>
  /// <param name="url"></param>
  /// <returns></returns>
   public Bitmap GetImage(ImageBuckleName buckle, string url)
  {
    url = ToMD5(url);
    
    lock (_Locker)
    {
      var rows = _Data.Select($"buckle='{buckle.ToString()}' AND url='{url}'");
      
      if (rows.Length > 0)
      {
        string file = Path.Combine(_baseFolder, rows[0]["name"].ToString());
        
        //C#加载图片文件，不占用文件句柄方式。
         byte[] bs = File.ReadAllBytes(file);
        MemoryStream ms = new MemoryStream(bs);
        return new Bitmap(Image.FromStream(ms));
      }
      else
      {
        return null;
      }
    }
  }
  
  /// <summary>
  /// 添加图片
  /// </summary>
  /// <param name="url"></param>
  /// <param name="img"></param>
  /// <param name="buckle"></param>
   public void AddImage(string url, Image img, ImageBuckleName buckle)
  {
    lock (_Locker)
    {
      string md5 = ToMD5(url);
      
      string dir = Path.Combine(_baseFolder, buckle.ToString());
      if (!Directory.Exists(dir)) Directory.CreateDirectory(dir);
      
      string ext = Path.GetExtension(url);
      string fileName = md5 + ext;
      fileName = buckle.ToString() + @"\" + fileName;
      
      string file = Path.Combine(_baseFolder, fileName);
      img.Save(file);
      
      if (File.Exists(file))
      {
        DataRow row = _Data.Rows.Add();
        row["buckle"] = buckle.ToString();
        row["name"] = fileName;
        row["url"] = md5;//将url转化为md5
         row["time"] = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
        _Data.AcceptChanges();
      }
    }
  }
  
  private DataTable GetFileTable()
  {
    DataTable dt = new DataTable("file");
    dt.Columns.Add("isid", typeof(int));
    dt.Columns.Add("buckle", typeof(String));
    dt.Columns.Add("url", typeof(String));
    dt.Columns.Add("name", typeof(String));
    dt.Columns.Add("time", typeof(String));
    return dt;
  }
  
  /// <summary>
  /// MD5加密，不可逆
  /// </summary>
  /// <param name="clearText">明文字符串</param>
  /// <returns></returns>
   private string ToMD5(string clearText)
  {
    MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
    byte[] encryptedBytes = md5.ComputeHash(UTF8Encoding.UTF8.GetBytes(clearText));
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < encryptedBytes.Length; i++)
    {
      sb.AppendFormat("{0:x2}", encryptedBytes[i]);
    }
    return sb.ToString().ToLower();
  }
}


//来源:C/S框架网 | www.csframework.com | QQ:23404761

C# Code:

/// <summary>
/// 图片存储子目录(可自定义)
/// </summary>
public enum ImageBuckleName
{
  large_images,
  small_images
}

//来源:C/S框架网 | www.csframework.com | QQ:23404761

缓存图片文件目录结构，以及图片数据库文件：

---

扫一扫加微信