private string GetPropertString(UInt32 deviceInstance, ConfigManagerAPI.DeviceInfo devPropInfo)
{
string property = "";
UInt32 propertyType = 0;
IntPtr buf = new IntPtr();
UInt32 bufSize = 0;
uint result = ConfigManagerAPI.CM_Get_DevNode_PropertyW(deviceInstance, ref devPropInfo, ref propertyType, buf, ref bufSize, 0);
if (result == SMALL_BAFFER && propertyType == STRING_TYPE)
{
buf = Marshal.AllocHGlobal((int)bufSize * 2);
result = ConfigManagerAPI.CM_Get_DevNode_PropertyW(deviceInstance, ref devPropInfo, ref propertyType, buf, ref bufSize, 0);
if (result == 0)
{
property = ReadNullTerminatedStringFromBuffer(buf, bufSize);
}
Marshal.FreeHGlobal(buf);
}
return(property);
}
private List <string> GetPropertStringList(UInt32 deviceInstance, ConfigManagerAPI.DeviceInfo devPropInfo)
{
List <string> property = new List <string>();
UInt32 propertyType = 0;
IntPtr buf = new IntPtr();
UInt32 bufSize = 0;
uint result = ConfigManagerAPI.CM_Get_DevNode_PropertyW(deviceInstance, ref devPropInfo, ref propertyType, buf, ref bufSize, 0);
if (result == SMALL_BAFFER && propertyType == (STRING_TYPE + LIST_TYPE))
{
buf = Marshal.AllocHGlobal((int)bufSize * 2);
result = ConfigManagerAPI.CM_Get_DevNode_PropertyW(deviceInstance, ref devPropInfo, ref propertyType, buf, ref bufSize, 0);
if (result == 0)
{
IntPtr pointer = buf;
while (bufSize > 0)
{
string element = ReadNullTerminatedStringFromBuffer(pointer, bufSize);
if (String.IsNullOrEmpty(element))
{
break;
}
int offset = element.Length + 1;
offset *= 2;
property.Add(element);
pointer = IntPtr.Add(pointer, offset);
}
}
Marshal.FreeHGlobal(buf);
}
return(property);
}