如何将这两个按钮转换为开关。
FlatButton(
onPressed: () => firebaseMessaging.subscribeToTopic('messages'),
child: const Text('Subscribe'),
),
FlatButton(
onPressed: () => firebaseMessaging.unsubscribeFromTopic('messages'),
child: const Text('Unsubscribe'),
),
答案 0 :(得分:0)
答案 1 :(得分:0)
您可以这样做:
Switch(
value: subscribed,
onValueChanged: (value) async {
if(subscribed) {
await firebaseMessaging.unsubscribeFromTopic('messages');
} else {
await firebaseMessaging.subscribeToTopic('messages');
}
setState(() => subscribed = value);
});
请注意,这必须是一个StatefulWidget
并带有subscribed
布尔值才能保持您的状态。那可能需要在某个地方初始化。