DocumentsContract.java 文件源码

public static boolean isChildDocument(ContentProviderClient client, Uri parentDocumentUri,
                                      Uri childDocumentUri) throws RemoteException {

    final Bundle in = new Bundle();
    in.putParcelable(DocumentsContract.EXTRA_URI, parentDocumentUri);
    in.putParcelable(DocumentsContract.EXTRA_TARGET_URI, childDocumentUri);

    final Bundle out = client.call(METHOD_IS_CHILD_DOCUMENT, null, in);
    if (out == null) {
        throw new RemoteException("Failed to get a reponse from isChildDocument query.");
    }
    if (!out.containsKey(DocumentsContract.EXTRA_RESULT)) {
        throw new RemoteException("Response did not include result field..");
    }
    return out.getBoolean(DocumentsContract.EXTRA_RESULT);
}