na-get-lib/NaGet.InteropServices/DllAccess.cs

   1 using System;\r
   2 using System.Reflection;\r
   3 using System.Runtime.InteropServices;\r
   4 \r
   5 namespace NaGet.InteropServices\r
   6 {\r
   7         /// <summary>\r
   8         /// DLLへの動的アクセスを行うクラス\r
   9         /// </summary>\r
  10         public class DllAccess : IDisposable\r
  11         {\r
  12                 #region Win32 API\r
  13                 \r
  14                 [DllImport("kernel32.dll", CharSet=CharSet.Auto)]\r
  15                 private extern static IntPtr LoadLibrary(string lpFileName);\r
  16                 \r
  17                 [DllImport("kernel32.dll")]\r
  18                 private extern static bool FreeLibrary(IntPtr hModule);\r
  19                 \r
  20                 [DllImport("kernel32.dll", CharSet=CharSet.Ansi)]\r
  21                 private extern static IntPtr GetProcAddress(IntPtr hModule, string lpProcName);\r
  22                 \r
  23                 #endregion\r
  24                 \r
  25                 private IntPtr hModule = IntPtr.Zero;\r
  26                 \r
  27                 /// <summary>\r
  28                 /// コンストラクタ。DLLを読み込む\r
  29                 /// </summary>\r
  30                 /// <param name="dllName">\r
  31                 /// DLLの名称。直接Win32APIのLoadLibraryにわたされる\r
  32                 /// </param>\r
  33                 public DllAccess(string dllName)\r
  34                 {\r
  35                         hModule = LoadLibrary(dllName);\r
  36                         if (hModule == IntPtr.Zero) {\r
  37                                 Exception innerEx = null;\r
  38                                 try {\r
  39                                         innerEx = Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());\r
  40                                 } catch {\r
  41                                 }\r
  42                                 throw new DllNotFoundException("Failed to LoadLibrary " + dllName, innerEx);\r
  43                         }\r
  44                 }\r
  45                 \r
  46                 /// <summary>\r
  47                 /// 関数をdelegateに変換して得る\r
  48                 /// </summary>\r
  49                 /// <param name="strProcName">\r
  50                 /// 関数名\r
  51                 /// </param>\r
  52                 /// <param name="type">\r
  53                 /// 関数の型。戻り値のdelegateのタイプ\r
  54                 /// </param>\r
  55                 /// <returns>\r
  56                 /// delegateに変換された関数\r
  57                 /// </returns>\r
  58                 public Delegate GetFunction(string strProcName, Type type)\r
  59                 {\r
  60                         IntPtr pFunc = GetProcAddress(hModule, strProcName);\r
  61                         if (pFunc == IntPtr.Zero) {\r
  62                                 int result = Marshal.GetHRForLastWin32Error();\r
  63                                 throw Marshal.GetExceptionForHR(result);\r
  64                         }\r
  65                         \r
  66                         return Marshal.GetDelegateForFunctionPointer(pFunc, type);\r
  67                 }\r
  68                 \r
  69                 /// <summary>\r
  70                 /// DLLの読み込みを閉じる\r
  71                 /// </summary>\r
  72                 public void Dispose()\r
  73                 {\r
  74                         if (hModule != IntPtr.Zero) {\r
  75                                 FreeLibrary(hModule);\r
  76                                 hModule = IntPtr.Zero;\r
  77                         }\r
  78                 }\r
  79         }\r
  80 }\r