In this example you'll learn how to share a file with other apps. We'll use a pdf file in this example although the code works with every other format as well.
The roadmap:
To share files we'll use a FileProvider, a class allowing secure file sharing between apps. A FileProvider can only share files in predefined directories, so let's define these.
Create a new XML file that will contain the paths, e.g. res/xml/filepaths.xml
Add the paths
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<files-path name="pdf_folder" path="documents/"/>
</paths>
<manifest>
...
<application>
...
<provider
android:name="android.support.v4.context.FileProvider"
android:authorities="com.mydomain.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/filepaths" />
</provider>
...
</application>
...
</manifest>
// We assume the file we want to load is in the documents/ subdirectory
// of the internal storage
File documentsPath = new File(Context.getFilesDir(), "documents");
File file = new File(documentsPath, "sample.pdf");
// This can also in one line of course:
// File file = new File(Context.getFilesDir(), "documents/sample.pdf");
Uri uri = FileProvider.getUriForFile(getContext(), "com.mydomain.fileprovider", file);
As you can see in the code we first make a new File class representing the file. To get a URI we ask FileProvider to get us one. The second argument is important: it passes the authority of a FileProvider. It must be equal to the authority of the FileProvider defined in the manifest.
Intent intent = ShareCompat.IntentBuilder.from(getContext())
.setType("application/pdf")
.setStream(uri)
.setChooserTitle("Choose bar")
.createChooserIntent()
.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
Context.startActivity(intent);
A chooser is a menu from which the user can choose with which app he/she wants to share the file. The flag Intent.FLAG_GRANT_READ_URI_PERMISSION is needed to grant temporary read access permission to the URI.