委托delegate的使用-动态加载DLL控件

上次利用Dllimport加载DLL控件时，却只能加载固定路径的DLL文件。对于一些路径不确定的DLL文件来说，这种方法是无法完全满足要求的。
或许有些人会认为DLL文件都可以利用引用方法来加载并进行开发，可对于非托管了DLL控件是无法实现的。这时，唯一的办法就是使用委托方法。
首先：要使用下面的类
public class DLLWrapper { ///<summary> ///API LoadLibrary ///</summary> [DllImport("Kernel32")] public static extern int LoadLibrary(String funcname); ///<summary> ///API GetProcAddress ///</summary> [DllImport("Kernel32")] public static extern int GetProcAddress(int handle,String funcname); ///<summary> ///API FreeLibrary ///</summary> [DllImport("Kernel32")] public static extern int FreeLibrary(int handle); ///<summary> ///通过非托管函数名转换为对应的委托, by jingzhongrong ///</summary> ///<param name="dllModule">通过LoadLibrary获得的DLL句柄</param> ///<param name="functionName">非托管函数名</param> ///<param name="t">对应的委托类型</param> ///<returns>委托实例，可强制转换为适当的委托类型</returns> public static Delegate GetFunctionAddress(int dllModule,string functionName,Type t) { int address=GetProcAddress(dllModule,functionName); if(address== 0) return null; else return Marshal.GetDelegateForFunctionPointer(new IntPtr(address),t); } ///<summary> ///将表示函数地址的IntPtr实例转换成对应的委托。 ///</summary> public static Delegate GetDelegateFromIntPtr(IntPtr address,Type t) { if(address==IntPtr.Zero) return null; else return Marshal.GetDelegateForFunctionPointer(address,t); } ///<summary> ///将表示函数地址的int转换成对应的委托。 ///</summary> public static Delegate GetDelegateFromIntPtr(int address,Type t) { if(address== 0) return null; else return Marshal.GetDelegateForFunctionPointer(new IntPtr(address),t); } } ///<summary> ///将表示函数地址的int转换成对应的委托。 ///</summary> public static Delegate GetDelegateFromIntPtr(int address,Type t) { if(address== 0) return null; else return Marshal.GetDelegateForFunctionPointer(new IntPtr(address),t); } } public class DLLWrapper { ///<summary> ///API LoadLibrary ///</summary> [DllImport("Kernel32")] public static extern int LoadLibrary(String funcname); ///<summary> ///API GetProcAddress ///</summary> [DllImport("Kernel32")] public static extern int GetProcAddress(int handle,String funcname); ///<summary> ///API FreeLibrary ///</summary> [DllImport("Kernel32")] public static extern int FreeLibrary(int handle); ///<summary> ///通过非托管函数名转换为对应的委托, by jingzhongrong ///</summary> ///<param name="dllModule">通过LoadLibrary获得的DLL句柄</param> ///<param name="functionName">非托管函数名</param> ///<param name="t">对应的委托类型</param> ///<returns>委托实例，可强制转换为适当的委托类型</returns> public static Delegate GetFunctionAddress(int dllModule,string functionName,Type t) { int address=GetProcAddress(dllModule,functionName); if(address== 0) return null; else return Marshal.GetDelegateForFunctionPointer(new IntPtr(address),t); } ///<summary> ///将表示函数地址的IntPtr实例转换成对应的委托。 ///</summary> public static Delegate GetDelegateFromIntPtr(IntPtr address,Type t) { if(address==IntPtr.Zero) return null; else return Marshal.GetDelegateForFunctionPointer(address,t); } ///<summary> ///将表示函数地址的int转换成对应的委托。 ///</summary> public static Delegate GetDelegateFromIntPtr(int address,Type t) { if(address== 0) return null; else return Marshal.GetDelegateForFunctionPointer(new IntPtr(address),t); } } 第二步骤使用 [DllImport("Kernel32")] public static extern int GetProcAddress(int handle,String funcname); [DllImport("Kernel32")] public static extern int LoadLibrary(String funcname); [DllImport("Kernel32")] public static extern int FreeLibrary(int handle); [DllImport("Kernel32")] public static extern int GetProcAddress(int handle,String funcname); [DllImport("Kernel32")] public static extern int LoadLibrary(String funcname); [DllImport("Kernel32")] public static extern int FreeLibrary(int handle); 第三步骤使用委托 public delegate string FOO(bool HDD, bool NIC, bool CPU, bool BIOS, string sRegistrationCode); public delegate string FOO(bool HDD, bool NIC, bool CPU, bool BIOS, string sRegistrationCode); 第四步骤，开始委托 int hModule = DLLWrapper.LoadLibrary(Server.MapPath("bin/aq82.dll")); Response.Write(hModule.ToString()); //if (inthModule == 0) FOO foo = (FOO)DLLWrapper.GetFunctionAddress(hModule, "FunctionName", typeof(FOO)); if (foo == null) { DLLWrapper.FreeLibrary(hModule); return; } Response.Write("<br/>"); Response.Write(foo(true, false, false, false, "R5LR-S4TQ"));
以上文章Google上找到了。本人测试时，完全可以使用