/// <summary>
/// 根据dll的路径，dll中的方法名，动态调用非托管dll的方法
/// </summary>
/// <param name="dllPath">dll的路径</param>
/// <param name="functionName">要调用的dll的方法名称</param>
/// <param name="delegateType">要将对应非托管dll中的方法名映射为C#的签名一致的委托类型</param>
/// <param name="msg">执行过程中的错误信息</param>
/// <param name="par">执行方法的参数</param>
/// <returns></returns>
private static object DynamicInvoke(string dllPath, string functionName, Type delegateType, out string msg, params object[] par)
{
msg = "";
int address = 0;
try
{
address = Kernel32Helper.LoadLibrary(dllPath);
if (address == 0)
{
//msg = "加载dll失败，dll路径：" + dllPath;
msg = "fail to load dll :" + dllPath;
return(null);
}
Delegate d1 = GetFunctionAddress(address, functionName, delegateType);
if (d1 == null)
{
//msg = "获取函数名称失败，函数名称：" + functionName;
msg = "fail to load function :" + functionName;
return(null);
}
object result = d1.DynamicInvoke(par);
Kernel32Helper.FreeLibrary(address);
return(result);
}
catch (Exception e)
{
if (address != 0)
{
Kernel32Helper.FreeLibrary(address);
}
msg = e.Message;
return(null);
}
}
/// <summary>
/// 根据非托管库的句柄，函数名称和指定委托类型，返回委托
/// </summary>
/// <param name="dllModule"></param>
/// <param name="functionName"></param>
/// <param name="t"></param>
/// <returns></returns>
private static Delegate GetFunctionAddress(int dllModule, string functionName, Type t)
{
int address = Kernel32Helper.GetProcAddress(dllModule, functionName); //得到地址
if (address == 0)
{
return(null);
}
else
{
return(Marshal.GetDelegateForFunctionPointer(new IntPtr(address), t));//将非托管函数指针转换为委托。
}
}
