如何使用kivy从Android检索联系人

Question

我尝试使用pyjnius检索联系人，可能是我犯了一些错误。谁能帮我解决这个问题

def build(self):
    try:
        PythonActivity=autoclass("org.renpy.android.PythonActivity")
        ContactsContract=autoclass("android.provider.ContactsContract")
        cr = PythonActivity.mActivity.getContentResolver()
        null = None # this will help to convert java examples into python ones :)
        cur = cr.query(ContactsContract.Contacts.CONTENT_URI,
                       null, null, null, null)
        CONTACTS_ID = '_id'
        if (cur.getCount() > 0):
            while (cur.moveToNext()):
                id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID)
                return Label(text=str(id).replace(' ', '\n'))
    except Exception as ex:
        return Label(text=str(ex).replace(' ', '\n'))