Hi, I am using the documentation provided here: [https://learn.microsoft.com/en-us/windows/win32/wpd_sdk/wpd-application-programming-interface to create an interface to portable devices (Android device and memory sticks). I have implemented the provided example code into my application but I have an issue with re-creating a directory after the original one was deleted. I can create a new directory on the device without issue. But if I navigate using windows explorer and delete the newly created directory or use pContent->Delete , I can't re-create a new one with the same name, using pContent->CreateObjectWithPropertiesOnly , unless I fully disconnect the device and connect it back again. I've gone through the documentation and can't find anything regarding "refreshing" the object list on the device. Am I overlooking something? Thank you, Guillaume D.

Windows Portable Devices can't re-create directory after deletion

Accepted answer

Jeanine Zhang-MSFT 9,181 Microsoft Vendor

Hello,

Welcome to Microsoft Q&A!

According to the Doc: IPortableDeviceContent::CreateObjectWithPropertiesOnly method

[in, out] ppszObjectID An optional string pointer to receive the name of the new object.
The SDK allocates this memory; the caller must release it using CoTaskMemFree.

I suggest you could try to use CoTaskMemFree function to release it. And then re-create a new one with the same name.

Thank you.

Jeanine

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Guillaume Doucet 25 Reputation points

2023-01-27T12:18:52.3666667+00:00

Hi,

thank you for your quick reply. I do release the memory for the created object pointer using CoTaskMemFree.

I use this code for creating the directory ( [https://learn.microsoft.com/en-us/windows/win32/wpd_sdk/transferring-a-properties-only-object-to-the-device ) and this one for deletion( [https://learn.microsoft.com/en-us/windows/win32/wpd_sdk/deleting-content-from-the-device ).

I have also realized that if I connect the android device on the computer, navigate to the target parent directory only using Windows Explorer, and create, then delete a directory with the same name as in my application, running the application afterwards fails to re-create the directory.

The inverse is also true. If I connect the phone and run my application to create and delete that directory, I can't use Explorer to manually create a new one. Even if my application is fully terminated. I can create a new directory but if I try to rename it to the same name, it reverts automatically to NewFolder.

The only way I've found to enable directory creation again is to disconnect the device and wait a few seconds before reconnecting.
Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor

2023-01-31T08:53:09.37+00:00

I test the official sample, and I couldn't reproduce the issue. Could you please test it with the official sample? Could you please tell us what is your OS version? And whether have you tried to use another portable devices?
Guillaume Doucet 25 Reputation points

2023-01-31T18:48:24.3166667+00:00

I could not reproduce either with the official sample. At a first glance the code appears slightly different than the example I had so I'll scan through it to find where my error is. Thanks!

Related to the sample, the repository mentions that the examples were created for/with Windows 7 and 8. Is there a "newer" API that I could use to interface portable devices with a C# application? I haven't found anything else than this sample and modifying the code to compile to a DLL library exposing the functionality to the C# side. Am I missing anything?
Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor

2023-02-01T01:48:52.4933333+00:00

As far as I'm concerned, there is no "newer" API that you could use to interface portable devices with a C# application.

Guillaume Doucet 25

Hi!

I managed to replicate the bug using the official sample! Apparently it's not a code issue but a directory issue. Hence the confusion.

For more context, I'm running the application on a Samsung Android phone. If I run the directory creation/deletion in This PC\Galaxy S20 5G\Stockage interne\Pictures it works fine.

But if I run it in: This PC\Galaxy S20 5G\Stockage interne\Android\data it doesn't work. I can actually read the directory properties AFTER it has been deleted, and trying to create a new directory fails.

Now do you know of any reason why this occurs? Is Android caching the sub-directories in the application data path?

This is the copied console output from the official sample:

WPD Sample Application
=======================================
0.  Enumerate all Devices
1.  Choose a Device
2.  Enumerate all content on the device
3.  Transfer content from the device
4.  Delete content from the device
5.  Move content already on the device to another location on the device
6   Transfer Image content to the device
7.  Transfer Music content to the device
8.  Transfer Contact (VCARD file) content to the device
9.  Transfer Contact (Defined by Properties Only) to the device
10. Create a folder on the device
11. Add a Contact Photo resource to an object
12. Read properties on a content object
13. Write properties on a content object
14. Get an object identifier from a Persistent Unique Identifier (PUID)
15. List all functional categories supported by the device
16. List all functional objects on the device
17. List all content types supported by the device
18. List rendering capabilities supported by the device
19. Register to receive device event notifications
20. Unregister from receiving device event notifications
21. List all events supported by the device
22. List all hint locations supported by the device
==(Advanced BULK property operations)==
23. Read properties on multiple content objects
24. Write properties on multiple content objects
25. Read properties on multiple content objects using object format
==(Update content operations)==
26. Update Image content (properties and data) on the device
27. Update Music content (properties and data) on the device
28. Update Contact content (properties and data) on the device
99. Exit
12
Enter the identifier of the object you wish to read properties from.
>o244
WPD_OBJECT_PARENT_ID: o2
WPD_OBJECT_NAME: data
WPD_OBJECT_PERSISTENT_UNIQUE_ID: {85087F60-0000-0000-0000-000000000000}
WPD_OBJECT_CONTENT_TYPE: {27E2E392-A111-48E0-AB0C-E17705A05F85}
WPD_OBJECT_FORMAT: {30010000-AE6C-4804-98BA-C57B46965FE7}
WPD Sample Application
=======================================
0.  Enumerate all Devices
1.  Choose a Device
2.  Enumerate all content on the device
3.  Transfer content from the device
4.  Delete content from the device
5.  Move content already on the device to another location on the device
6   Transfer Image content to the device
7.  Transfer Music content to the device
8.  Transfer Contact (VCARD file) content to the device
9.  Transfer Contact (Defined by Properties Only) to the device
10. Create a folder on the device
11. Add a Contact Photo resource to an object
12. Read properties on a content object
13. Write properties on a content object
14. Get an object identifier from a Persistent Unique Identifier (PUID)
15. List all functional categories supported by the device
16. List all functional objects on the device
17. List all content types supported by the device
18. List rendering capabilities supported by the device
19. Register to receive device event notifications
20. Unregister from receiving device event notifications
21. List all events supported by the device
22. List all hint locations supported by the device
==(Advanced BULK property operations)==
23. Read properties on multiple content objects
24. Write properties on multiple content objects
25. Read properties on multiple content objects using object format
==(Update content operations)==
26. Update Image content (properties and data) on the device
27. Update Music content (properties and data) on the device
28. Update Contact content (properties and data) on the device
99. Exit
10
Enter the identifier of the parent object which the folder will be created under.
>o244
Enter the name of the the folder to create.
>TestDirectory
The folder was created on the device.
The newly created object's ID is 'o10BB'
WPD Sample Application
=======================================
0.  Enumerate all Devices
1.  Choose a Device
2.  Enumerate all content on the device
3.  Transfer content from the device
4.  Delete content from the device
5.  Move content already on the device to another location on the device
6   Transfer Image content to the device
7.  Transfer Music content to the device
8.  Transfer Contact (VCARD file) content to the device
9.  Transfer Contact (Defined by Properties Only) to the device
10. Create a folder on the device
11. Add a Contact Photo resource to an object
12. Read properties on a content object
13. Write properties on a content object
14. Get an object identifier from a Persistent Unique Identifier (PUID)
15. List all functional categories supported by the device
16. List all functional objects on the device
17. List all content types supported by the device
18. List rendering capabilities supported by the device
19. Register to receive device event notifications
20. Unregister from receiving device event notifications
21. List all events supported by the device
22. List all hint locations supported by the device
==(Advanced BULK property operations)==
23. Read properties on multiple content objects
24. Write properties on multiple content objects
25. Read properties on multiple content objects using object format
==(Update content operations)==
26. Update Image content (properties and data) on the device
27. Update Music content (properties and data) on the device
28. Update Contact content (properties and data) on the device
99. Exit
4
Enter the identifier of the object you wish to delete.
>o10BB
The object 'o10BB' was deleted from the device.
WPD Sample Application
=======================================
0.  Enumerate all Devices
1.  Choose a Device
2.  Enumerate all content on the device
3.  Transfer content from the device
4.  Delete content from the device
5.  Move content already on the device to another location on the device
6   Transfer Image content to the device
7.  Transfer Music content to the device
8.  Transfer Contact (VCARD file) content to the device
9.  Transfer Contact (Defined by Properties Only) to the device
10. Create a folder on the device
11. Add a Contact Photo resource to an object
12. Read properties on a content object
13. Write properties on a content object
14. Get an object identifier from a Persistent Unique Identifier (PUID)
15. List all functional categories supported by the device
16. List all functional objects on the device
17. List all content types supported by the device
18. List rendering capabilities supported by the device
19. Register to receive device event notifications
20. Unregister from receiving device event notifications
21. List all events supported by the device
22. List all hint locations supported by the device
==(Advanced BULK property operations)==
23. Read properties on multiple content objects
24. Write properties on multiple content objects
25. Read properties on multiple content objects using object format
==(Update content operations)==
26. Update Image content (properties and data) on the device
27. Update Music content (properties and data) on the device
28. Update Contact content (properties and data) on the device
99. Exit
12
Enter the identifier of the object you wish to read properties from.
>o10BB
WPD_OBJECT_PARENT_ID: o244
WPD_OBJECT_NAME: TestDirectory
WPD_OBJECT_PERSISTENT_UNIQUE_ID: {EC8FC050-FFFF-FFFF-0000-000000000000}
WPD_OBJECT_CONTENT_TYPE: {27E2E392-A111-48E0-AB0C-E17705A05F85}
WPD_OBJECT_FORMAT: {30010000-AE6C-4804-98BA-C57B46965FE7}
WPD Sample Application
=======================================
0.  Enumerate all Devices
1.  Choose a Device
2.  Enumerate all content on the device
3.  Transfer content from the device
4.  Delete content from the device
5.  Move content already on the device to another location on the device
6   Transfer Image content to the device
7.  Transfer Music content to the device
8.  Transfer Contact (VCARD file) content to the device
9.  Transfer Contact (Defined by Properties Only) to the device
10. Create a folder on the device
11. Add a Contact Photo resource to an object
12. Read properties on a content object
13. Write properties on a content object
14. Get an object identifier from a Persistent Unique Identifier (PUID)
15. List all functional categories supported by the device
16. List all functional objects on the device
17. List all content types supported by the device
18. List rendering capabilities supported by the device
19. Register to receive device event notifications
20. Unregister from receiving device event notifications
21. List all events supported by the device
22. List all hint locations supported by the device
==(Advanced BULK property operations)==
23. Read properties on multiple content objects
24. Write properties on multiple content objects
25. Read properties on multiple content objects using object format
==(Update content operations)==
26. Update Image content (properties and data) on the device
27. Update Music content (properties and data) on the device
28. Update Contact content (properties and data) on the device
99. Exit
10
Enter the identifier of the parent object which the folder will be created under.
>o244
Enter the name of the the folder to create.
>TestDirectory
! Failed to create a new folder on the device, hr = 0x80004005

Guillaume Doucet 25 Reputation points

2023-02-01T15:20:06.9233333+00:00

I apologize if this gets duplicated but the last comment I posted doesn't seem to appear.

I managed to replicate the bug using the official sample. The issue appears if I run the code in the device/Android/data directory or any of its sub-directories. But doesn't appear if I run it elsewhere.

This is the copied console output from the WpdApiSample: WpdApiSample_Failure.txt
Jeanine Zhang-MSFT 9,181 Reputation points Microsoft Vendor

2023-02-02T08:10:48.15+00:00

According to your description, it's not a code issue, it is related to enviroment. Since the enviroment issue is hard to troubleshoot on the forum support, to resolve this issue as soon as possible, you can open an incident via 'Contact us' tab at link below: https://developer.microsoft.com/en-us/windows/support/

Please choose the 'Technical Support - Coding/Debugging' for Windows SDK for this issue. In-addition, if the support engineer determines that the issue is the result of a bug the service request will be a no-charge case and you won't be charged.
Guillaume Doucet 25 Reputation points

2023-02-02T11:59:28.75+00:00

I will look into it! Thank you for your help!

Windows Portable Devices can't re-create directory after deletion

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