+ In previous versions of Android, your app could use the Storage Access + Framework to allow users to select files from their cloud storage accounts, + such as Google Drive. However, there was no way to represent files that did + not have a direct bytecode representation; every file was required to provide + an input stream. +
+ ++ Android N adds the concept of virtual files to the Storage Access + Framework. The virtual files feature allows your + {@link android.provider.DocumentsProvider} to return document URIs that can be + used with an {@link android.content.Intent#ACTION_VIEW} intent even if they + don't have a direct bytecode representation. Android N also allows you to + provide alternate formats for user files, virtual or otherwise. +
+ ++ To get a URI for a virtual document in your app, first you create an + {@link android.content.Intent} to open the file picker UI. Since an app + cannot directly open a virtual file by using the + {@link android.content.ContentResolver#openInputStream(Uri) openInputStream()} + method, your app does not receive any virtual files if you include the + {@link android.content.Intent#CATEGORY_OPENABLE} category. +
+ ++ After the user has made a selection, the system calls the + {@link android.app.Activity#onActivityResult onActivityResult()} method. + Your app can retrieve the URI of the virtual file and get an input stream, as + demonstrated in the code snippet below. +
+ +
+ // Other Activity code ...
+
+ final static private int REQUEST_CODE = 64;
+
+ // We listen to the OnActivityResult event to respond to the user's selection.
+ @Override
+ public void onActivityResult(int requestCode, int resultCode,
+ Intent resultData) {
+ try {
+ if (requestCode == REQUEST_CODE &&
+ resultCode == Activity.RESULT_OK) {
+
+ Uri uri = null;
+
+ if (resultData != null) {
+ uri = resultData.getData();
+
+ ContentResolver resolver = getContentResolver();
+
+ // Before attempting to coerce a file into a MIME type,
+ // check to see what alternative MIME types are available to
+ // coerce this file into.
+ String[] streamTypes =
+ resolver.getStreamTypes(uri, "*/*");
+
+ AssetFileDescriptor descriptor =
+ resolver.openTypedAssetFileDescriptor(
+ uri,
+ streamTypes[0],
+ null);
+
+ // Retrieve a stream to the virtual file.
+ InputStream inputStream = descriptor.createInputStream();
+ }
+ }
+ } catch (Exception ex) {
+ Log.e("EXCEPTION", "ERROR: ", ex);
+ }
+ }
+
+
++ For more information about accessing user files, see the + Storage + Access Frameworks guide. +
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