我有一个连接到 Firebase 文档的流，并且我一直在收听文档的任何更改。
我想在文档更改时更新我的应用程序的某些部分，因此我使流全局可用，并在不同的屏幕上使用 StreamBuilders，以便屏幕上可以使用最新的数据。
全局流和多个StreamBuilders会不会有问题？当 StreamBuilders 在多个屏幕上创建时，应用程序如何工作？
这是我的全局流：
Stream userDocGlobalStream =
Firestore.instance.collection("user").document(CurrentUserDetails.id).snapshots();
这是我的一个屏幕小部件的构建方法（我根据流数据更改按钮的颜色）：
@override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
return StreamBuilder(
stream: userDocGlobalStream,
builder: (context, snapShot) {
return Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(30),
side: BorderSide(color: theme.primaryColor)),
elevation: 30,
child: Container(
margin: EdgeInsets.all(10),
child: Column(
children: <Widget>[
Column(
crossAxisAlignment: CrossAxisAlignment
.stretch, //need to use it to strech the items horizontally
children: <Widget>[
Container(
//to think, it is used for the background color of the picture. can undo it later
decoration: BoxDecoration(
color: theme.primaryColor.withAlpha(10),
borderRadius: BorderRadius.circular(10),
),
padding: EdgeInsets.all(10),
child: GestureDetector(
onTap: () {}, //go to user profile when pressed.
child: CircleAvatar(
radius: 70,
backgroundImage: NetworkImage(userImageUrl),
),
),
),
],
),
Container(
margin: EdgeInsets.symmetric(vertical: 10),
child: FittedBox(
child: Text(
"Username : $username ",
),
),
),
Container(
margin: EdgeInsets.symmetric(vertical: 10),
child: FittedBox(
child: Text(
"interests : ${interests.toString().replaceAll("[", "").replaceAll("]", "")} ",
),
),
),
Container(
margin: EdgeInsets.symmetric(vertical: 10),
child: FittedBox(
child: Text("Distance from you : $distanceFromUser KM"),
),
), //to do address and km from you should go here
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
IconButton(
color: theme.primaryColor,
icon: Icon(Icons.chat),
onPressed: () {}, //send a message to the user
),
IconButton(
color: Colors.cyan,
icon: CurrentUserDetails.friendRequestsSent.contains(
userId) //to do=> THE ICON MUST CHANGE WITH EVERY CHANGE OF THE DATA
? Icon(
Icons.person,
color: Colors.black,
)
: CurrentUserDetails.friends.contains(userId)
? Icon(
Icons.person,
color: Colors.green,
)
: Icon(Icons.person_add),
onPressed: () {
try {
//to do
CurrentUserDetails.friendRequestsSent
.contains(userId)
? DoNothingAction()
//Cancel the sent request:
: CurrentUserDetails.friendRequestsReceived
.contains(userId)
? DoNothingAction()
//accept friend request:
: CurrentUserDetails.friends
.contains(userId)
? DoNothingAction()
//delete the friend:
: DatabaseManagement().sendFriendRequest(
CurrentUserDetails.id,
userId); //userId is the id of the user we are showing the widget for
} catch (e) {
showDialog(
context: context,
builder: (ctx) => DialogueWidget(
titleText: "Error occured",
contentText:
e.toString(), //to do+> change the er
),
);
}
} //send friend request when this button is pressed
),
IconButton(
color: Colors.red[300],
icon: Icon(Icons.location_on),
onPressed:
() {}, //show a map with a users location details on it.
)
],
)
],
),
),
);
},
);
}
}