原文:
C#开发奇技淫巧二:根据dll文件加载C++或者Delphi插件
这两天忙着把框架改为支持加载C++和Delphi的插件,来不及更新blog了。
原来的写的框架只支持c#插件,这个好做,直接用c#的反射功能便可。但是公司不是所有人都搞C#,也不是所有的程序C#都能很好的完成,又或者其他公司提供的API不是C#的,这个时候,就需要这个框架能够支持多种语言了。
废话不多说,进入正题。
上网一搜,C#加载非托管的dll,无非就是使用 DllImportAttribute 。然而,这个属性里面要指明dll所在的路径,因为又是写在属性中,因此是在编译的时候就已经把路径写死了,不能动态指定路径加载。
于是又找了下,终于发现了c#中的一个函数:Marshal.GetDelegateForFunctionPointer。这个函数的功能就是将非托管的函数指针转换为委托。至此,任务完成。Dll的功能无非提提供各种函数,组成所谓的API,有了上述的方法之后,在C#中定义相关的委托(方法的参数列表和参数类型要跟非托管的Dll的参数类型和参数列表对应,具体的对应请google),然后调用上述方法,将非托管的dll转换为相应的委托,这样就能调用非托管的dll了。
在C#中,我们定义相关的接口,在方法实现中调用相应的委托,这样,一个插件对象就完成了。下面给出相应的类库和使用实例。
1
public
class
LoadDll
2 {
3 #region Win32 API : Load dll
4 [DllImport( " kernel32.dll " )]
5 public static extern IntPtr LoadLibrary( string path);
6
7 [DllImport( " kernel32.dll " )]
8 public static extern IntPtr GetProcAddress(IntPtr lib, string funcName);
9
10 [DllImport( " kernel32.dll " )]
11 public static extern bool FreeLibrary(IntPtr lib);
12
13 [DllImport( " kernel32.dll " )]
14 public static extern IntPtr GetStdHandle( int nStdHandle);
15
16 [DllImport( " user32 " , EntryPoint = " CallWindowProc " )]
17 public static extern int CallWindowProc(IntPtr lpPreWndFunc, int hwnd, int msg, int wParam, int lParam);
18 #endregion
19
20 private IntPtr _dllLib;
21
22 /// <summary>
23 /// Initializes a new instance of the <see cref="LoadDll"/> class.
24 /// </summary>
25 public LoadDll()
26 {
27
28 }
29
30 /// <summary>
31 /// Initializes a new instance of the <see cref="LoadDll"/> class.
32 /// </summary>
33 /// <param name="path"> The path. </param>
34 public LoadDll( string path)
35 {
36 _dllLib = LoadLibrary(path);
37 }
38
39 /// <summary>
40 /// 注销对象时释放资源
41 /// <see cref="LoadDll"/> is reclaimed by garbage collection.
42 /// </summary>
43 ~ LoadDll()
44 {
45 FreeLibrary(_dllLib);
46 }
47
48 /// <summary>
49 /// 初始化dll的路径
50 /// </summary>
51 /// <param name="path"> The path. </param>
52 public void InitPath( string path)
53 {
54 if (_dllLib == IntPtr.Zero)
55 _dllLib = LoadLibrary(path);
56 }
57
58 /// <summary>
59 /// 根据非托管的dll中的方法名称映射成托管的委托类型
60 /// </summary>
61 /// <param name="methodName"> 非托管的dll中的方法名称 </param>
62 /// <param name="methodType"> 托管的委托类型 </param>
63 /// <returns></returns>
64 public Delegate InvokeMethod( string methodName, Type methodType)
65 {
66 // 获取非托管的dll中方法的地址
67 var methodPtr = GetProcAddress(_dllLib, methodName);
68 // 将非托管的方法转换为委托
69 return Marshal.GetDelegateForFunctionPointer(methodPtr, methodType);
70 }
71 }
2 {
3 #region Win32 API : Load dll
4 [DllImport( " kernel32.dll " )]
5 public static extern IntPtr LoadLibrary( string path);
6
7 [DllImport( " kernel32.dll " )]
8 public static extern IntPtr GetProcAddress(IntPtr lib, string funcName);
9
10 [DllImport( " kernel32.dll " )]
11 public static extern bool FreeLibrary(IntPtr lib);
12
13 [DllImport( " kernel32.dll " )]
14 public static extern IntPtr GetStdHandle( int nStdHandle);
15
16 [DllImport( " user32 " , EntryPoint = " CallWindowProc " )]
17 public static extern int CallWindowProc(IntPtr lpPreWndFunc, int hwnd, int msg, int wParam, int lParam);
18 #endregion
19
20 private IntPtr _dllLib;
21
22 /// <summary>
23 /// Initializes a new instance of the <see cref="LoadDll"/> class.
24 /// </summary>
25 public LoadDll()
26 {
27
28 }
29
30 /// <summary>
31 /// Initializes a new instance of the <see cref="LoadDll"/> class.
32 /// </summary>
33 /// <param name="path"> The path. </param>
34 public LoadDll( string path)
35 {
36 _dllLib = LoadLibrary(path);
37 }
38
39 /// <summary>
40 /// 注销对象时释放资源
41 /// <see cref="LoadDll"/> is reclaimed by garbage collection.
42 /// </summary>
43 ~ LoadDll()
44 {
45 FreeLibrary(_dllLib);
46 }
47
48 /// <summary>
49 /// 初始化dll的路径
50 /// </summary>
51 /// <param name="path"> The path. </param>
52 public void InitPath( string path)
53 {
54 if (_dllLib == IntPtr.Zero)
55 _dllLib = LoadLibrary(path);
56 }
57
58 /// <summary>
59 /// 根据非托管的dll中的方法名称映射成托管的委托类型
60 /// </summary>
61 /// <param name="methodName"> 非托管的dll中的方法名称 </param>
62 /// <param name="methodType"> 托管的委托类型 </param>
63 /// <returns></returns>
64 public Delegate InvokeMethod( string methodName, Type methodType)
65 {
66 // 获取非托管的dll中方法的地址
67 var methodPtr = GetProcAddress(_dllLib, methodName);
68 // 将非托管的方法转换为委托
69 return Marshal.GetDelegateForFunctionPointer(methodPtr, methodType);
70 }
71 }
调用:
1
loadDll
=
new
LoadDll(path);
2 stop = (StopHandler)loadDll.InvokeMethod( " stop " , typeof (StopHandler));
3 start = (StartHandler)loadDll.InvokeMethod( " start " , typeof (StartHandler));
4 init = (InitHandler)loadDll.InvokeMethod( " init " , typeof (InitHandler));
5 query = (QueryHandler)loadDll.InvokeMethod( " query " , typeof (QueryHandler));
6 setDatabaseInfo = (SetDatabaseInfoHandler)loadDll.InvokeMethod( " setDatabaseInfo " , typeof (SetDatabaseInfoHandler));
7 setMonitorInfo = (SetMonitorInfoHandler)loadDll.InvokeMethod( " setMonitorInfo " , typeof (SetMonitorInfoHandler));
2 stop = (StopHandler)loadDll.InvokeMethod( " stop " , typeof (StopHandler));
3 start = (StartHandler)loadDll.InvokeMethod( " start " , typeof (StartHandler));
4 init = (InitHandler)loadDll.InvokeMethod( " init " , typeof (InitHandler));
5 query = (QueryHandler)loadDll.InvokeMethod( " query " , typeof (QueryHandler));
6 setDatabaseInfo = (SetDatabaseInfoHandler)loadDll.InvokeMethod( " setDatabaseInfo " , typeof (SetDatabaseInfoHandler));
7 setMonitorInfo = (SetMonitorInfoHandler)loadDll.InvokeMethod( " setMonitorInfo " , typeof (SetMonitorInfoHandler));
c++中的导出方法:
1
///
插件导出方法
2 extern " C " __declspec(dllexport) void setDatabaseInfo(LPCTSTR dbServer, LPCTSTR dbUser, LPCTSTR dbPass, LPCTSTR dbName);
3 extern " C " __declspec(dllexport) void setMonitorInfo(LPCTSTR _agentBm, LPCTSTR _com);
4 extern " C " __declspec(dllexport) void init();
5 extern " C " __declspec(dllexport) void start();
6 extern " C " __declspec(dllexport) void stop();
7 extern " C " __declspec(dllexport) LPCTSTR query(LPCTSTR devname, LPCTSTR id);
2 extern " C " __declspec(dllexport) void setDatabaseInfo(LPCTSTR dbServer, LPCTSTR dbUser, LPCTSTR dbPass, LPCTSTR dbName);
3 extern " C " __declspec(dllexport) void setMonitorInfo(LPCTSTR _agentBm, LPCTSTR _com);
4 extern " C " __declspec(dllexport) void init();
5 extern " C " __declspec(dllexport) void start();
6 extern " C " __declspec(dllexport) void stop();
7 extern " C " __declspec(dllexport) LPCTSTR query(LPCTSTR devname, LPCTSTR id);
C#中的委托
1
///
<summary>
2 /// 处理Stop事件
3 /// </summary>
4 public delegate void StopHandler();
5 /// <summary>
6 /// 处理Start事件
7 /// </summary>
8 public delegate void StartHandler();
9 /// <summary>
10 /// 处理Init事件
11 /// </summary>
12 public delegate void InitHandler();
13 /// <summary>
14 /// 处理Query事件
15 /// </summary>
16 public delegate string QueryHandler( string devName, string id);
17 /// <summary>
18 /// 处理SetDataBaseInfo事件
19 /// </summary>
20 public delegate void SetDatabaseInfoHandler( string server, string user, string password, string dbName);
21 /// <summary>
22 /// 处理SetMonitorInfo事件
23 /// </summary>
24 public delegate void SetMonitorInfoHandler( string agentBm, string com);
2 /// 处理Stop事件
3 /// </summary>
4 public delegate void StopHandler();
5 /// <summary>
6 /// 处理Start事件
7 /// </summary>
8 public delegate void StartHandler();
9 /// <summary>
10 /// 处理Init事件
11 /// </summary>
12 public delegate void InitHandler();
13 /// <summary>
14 /// 处理Query事件
15 /// </summary>
16 public delegate string QueryHandler( string devName, string id);
17 /// <summary>
18 /// 处理SetDataBaseInfo事件
19 /// </summary>
20 public delegate void SetDatabaseInfoHandler( string server, string user, string password, string dbName);
21 /// <summary>
22 /// 处理SetMonitorInfo事件
23 /// </summary>
24 public delegate void SetMonitorInfoHandler( string agentBm, string com);
接下来怎么搞,你们都懂的