/// <summary>
/// 遍历从属服务
/// </summary>
/// <param name="serviceHandle"></param>
/// <param name="state">选择性遍历（活动、非活动、全部）</param>
private static string[] EnumDependentServices(IntPtr serviceHandle, EnumServiceState state)
{
int bytesNeeded = 0; //存放从属服务的空间大小，由API返回
int numEnumerated = 0; //从属服务数，由API返回
//先尝试以空结构获取，如获取成功说明从属服务为空，否则拿到上述俩值
if (Win32Class.EnumDependentServices(serviceHandle, state, IntPtr.Zero, 0, ref bytesNeeded, ref numEnumerated))
{
return(new string[0]);
}
if (Marshal.GetLastWin32Error() != 0xEA) //仅当错误值不是大小不够(ERROR_MORE_DATA)时才抛异常
{
throw new Win32Exception();
}
//在非托管区域创建指针
IntPtr structsStart = Marshal.AllocHGlobal(new IntPtr(bytesNeeded));
try
{
//往上述指针处塞存放从属服务的结构组，每个从属服务是一个结构
if (!Win32Class.EnumDependentServices(serviceHandle, state, structsStart, bytesNeeded, ref bytesNeeded, ref numEnumerated))
{
throw new Win32Exception();
}
string[] dependentServices = new string[numEnumerated];
int sizeOfStruct = Marshal.SizeOf(typeof(Win32Class.ENUM_SERVICE_STATUS)); //每个结构的大小
long structsStartAsInt64 = structsStart.ToInt64();
for (int i = 0; i < numEnumerated; i++)
{
Win32Class.ENUM_SERVICE_STATUS structure = new Win32Class.ENUM_SERVICE_STATUS();
IntPtr ptr = new IntPtr(structsStartAsInt64 + i * sizeOfStruct); //根据起始指针、结构次序和结构大小推算各结构起始指针
Marshal.PtrToStructure(ptr, structure); //根据指针拿到结构
dependentServices[i] = structure.serviceName; //从结构中拿到服务名
}
return(dependentServices);
}
finally
{
Marshal.FreeHGlobal(structsStart);
}
}
/// <summary>
/// 遍历从属服务
/// </summary>
/// <param name="serviceHandle"></param>
/// <param name="state">选择性遍历（活动、非活动、全部）</param>
private static string[] EnumDependentServices(IntPtr serviceHandle, EnumServiceState state)
{
int bytesNeeded = 0; //存放从属服务的空间大小，由API返回
int numEnumerated = 0; //从属服务数，由API返回
//先尝试以空结构获取，如获取成功说明从属服务为空，否则拿到上述俩值
if (Win32Class.EnumDependentServices(serviceHandle, state, IntPtr.Zero, 0, ref bytesNeeded, ref numEnumerated))
{
return new string[0];
}
if (Marshal.GetLastWin32Error() != 0xEA) //仅当错误值不是大小不够(ERROR_MORE_DATA)时才抛异常
{
throw new Win32Exception();
}
//在非托管区域创建指针
IntPtr structsStart = Marshal.AllocHGlobal(new IntPtr(bytesNeeded));
try
{
//往上述指针处塞存放从属服务的结构组，每个从属服务是一个结构
if (!Win32Class.EnumDependentServices(serviceHandle, state, structsStart, bytesNeeded, ref bytesNeeded, ref numEnumerated))
{
throw new Win32Exception();
}
string[] dependentServices = new string[numEnumerated];
int sizeOfStruct = Marshal.SizeOf(typeof(Win32Class.ENUM_SERVICE_STATUS)); //每个结构的大小
long structsStartAsInt64 = structsStart.ToInt64();
for (int i = 0; i < numEnumerated; i++)
{
Win32Class.ENUM_SERVICE_STATUS structure = new Win32Class.ENUM_SERVICE_STATUS();
IntPtr ptr = new IntPtr(structsStartAsInt64 + i * sizeOfStruct); //根据起始指针、结构次序和结构大小推算各结构起始指针
Marshal.PtrToStructure(ptr, structure); //根据指针拿到结构
dependentServices[i] = structure.serviceName; //从结构中拿到服务名
}
return dependentServices;
}
finally
{
Marshal.FreeHGlobal(structsStart);
}
}
