Flutter 可选择的Text

      Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: <Widget>[
          TextField(
              controller: TextEditingController(text: 'initial value'),
              readOnly: true,
              maxLines: null,
              decoration: null),
          SizedBox(height: 20),
          SelectableText('home page'),
        ],
      ),