Excuse me for my bad english, please help me solve this problem. I able to retrieve file from Android Device using WPD but failed to transfer back to Android Device. I followed the tutorial in https://dzone.com/articles/windows-portable-devices-0 but that method only applies to devices with drive letter. Thank you.
Sorry for the question, I already found a solution. The method used in the article is actually meant for PortableDeviceFolder.Id for its second parameter string parentObjectId, not a directory path in my Android Device.