在下载/文档文件夹中为文件类型/扩展名注册 Android 应用程序

Question

I am currently trying to have my app opened when the user clicks a certain file in their file browser (eg .xyz ).

The code I have for this in my manifest file is

<intent-filter>
      <action android:name="android.intent.action.VIEW" />
      <category android:name="android.intent.category.DEFAULT" />
      <category android:name="android.intent.category.BROWSABLE" />
      <data android:scheme="file"
                android:host="*" />
      <data android:scheme="content"
                android:host="*" />
      <data android:mimeType="application/octet-stream" />
      <data android:pathPattern=".*\\..*\\..*\\..*\\..*\\.xyz" />
      <data android:pathPattern=".*\\..*\\..*\\..*\\.xyz" />
      <data android:pathPattern=".*\\..*\\..*\\.xyz" />
      <data android:pathPattern=".*\\..*\\.xyz" />
      <data android:pathPattern=".*\\.xyz" />
      <data android:pathPattern="*.xyz" />
</intent-filter>

This seems to work for files that are stored on the phone storage, eg in the Android/ folder, but not for files stored in the Documents and Downloads places. That is because the uri of the file there is something like " content://com.android.providers.downloads.documents/document/msf%3A45 ", so the pathPattern does not work for it and the file browser says "Can't open file".

Is there any way to make opening the own app when the user clicks on files with the .xyz extension work in these two locations? (I do not want the app to open any binary file, only the ones with the specified extension)

One alternative I thought about was using a custom mime type to save the files (eg application/my_xyz_type ) and to then change the line

<data android:mimeType="application/octet-stream" />

to

<data android:mimeType="application/my_xyz_type" />

But when I do this using values.put(MediaStore.MediaColumns.MIME_TYPE, "application/my_xyz_type") , the file gets saved as a binary file with application/octet-stream as the mime type. I am therefore assuming it is not possible to store files with a custom mime type.

Answer 1

"I am currently trying to have my app opened when the user clicks a certain file in their file browser (eg .xyz)

That has never been a good option in Android for "custom" file extensions, and it is fairly unrealistic in modern versions.

This seems to work for files that are stored on the phone storage, eg in the Android/ folder

Not necessarily. The behavior will vary by OS version and "file browser" app.

Is there any way to make opening the own app when the user clicks on files with the.xyz extension work in these two locations?

No. More generally, you should assume that a content Uri does not have a useful file extension, just as http and https Uri values often do not have a useful file extension.

One alternative I thought about was using a custom mime type to save the files

Your <intent-filter> is not limited to files that your app is involved in saving.

I am therefore assuming it is not possible to store files with a custom mime type

That would not surprise me, though I have not tried it personally. MediaStore might check your supplied MIME type against a list of MIME types that it is willing to support and might swap in application/octet-stream as a default if your MIME type is not on the list. This is another thing whose behavior might vary by OS version (and maybe by device manufacturer).