Question

我正在做一个论坛移动应用程序，我想在用户上传帖子时显示其个人资料图片和用户名。我已经将一个ownerid字段（这是发布人员的uid）以及发布详细信息存储到firebase中。使用uid，如何访问用户的显示名称和个人资料图片？

这是我的帖子课：

with responses as (
  select id, client_id, user_id, 
         row_number() 
           over (order by client_id, user_id, id) 
           as dialog_id
    from conversations
   where incoming = false
), dialogs as (
  select c.*, min(dialog_id) as dialog_id
    from conversations c
    join responses r
      on r.client_id = c.client_id
     and r.user_id = c.user_id
     and r.id >= c.id
   group by c.id, c.client_id, c.message, c.user_id, c.incoming
)
select dialog_id, client_id,
       array_agg(message order by id) 
         filter (where incoming = true) 
           as client_message,
       user_id,
       max(message) 
         filter (where incoming = false) 
           as user_message  
  from dialogs
 group by dialog_id, client_id, user_id
order by dialog_id;

//在此使用了未来构建器

class Post { //for forums


String title;
  String content;
  String timestamp;
  String imageurl;
  String username;
  String profilePicture;
  String documentid;
  String ownerid;
  Map<String, dynamic> saved = {};
  Map<String, dynamic> upvotes = {};
  


  Post(
    this.title,
    this.content,
    this.timestamp,
    this.imageurl,
    this.username,
    this.profilePicture,
    this.documentid,
    this.ownerid,
    this.saved,
    this.upvotes
    //this.image
  );

  Post.fromSnapshot(DocumentSnapshot snapshot) : 
  title = snapshot["title"],
  content = snapshot['content'],
  timestamp = snapshot['timestamp'],
  imageurl = snapshot['imageurl'],
  username = snapshot['username'],
  profilePicture = snapshot['profilePicture'],
  documentid = snapshot['documentid'],
  upvotes = snapshot['upvotes'],
  ownerid = snapshot['ownerid'],
  saved = snapshot['saved'];
}


FutureBuilder( 
              future: Firestore.instance.collection('users').document(post['ownerid']).get(),
              builder: (context, snapshot) {
                if (snapshot.connectionState == ConnectionState.done) {
                  return Text(snapshot.data['username'], style: TextStyle(fontWeight: FontWeight.bold,
                      fontSize: 16, decoration: TextDecoration.underline, color: Colors.grey[100]),
                   );
                } else {
                  return CircularProgressIndicator();
                }
              }, 
          ),

Answer 1

假设您在Firebase中已经有一个名为“用户”的集合，您将在其中存储登录时的用户数据。还有一个名为“ uid”的字段，您将在其中存储uid

在firebase中检查具有相同uid的用户并提取详细信息

QuerySnapshot snapshot = awaitFirestore.instance.collection("users").where("uid",isEqualTo:ownerId).getDocuments()

//if you are sure that there is exactly one user with the same uid
Map<String,dynamic> userInfo = snapshot.documents[0].data;

要保存读取，我建议使用用户的uid来命名“用户”集合的文档ID，因为在这种情况下，您可以进行直接查询，例如

 DocumentSnapshot doc = await Firestore.instance.collection("users").document(ownerId).get();

//To access any fields on the document retrieved
String username = doc.data["username"] //assuming the fields name in the document 
                                       //is "username"

Answer 2

除控制台外，您无权直接访问所有经过Firebase身份验证的用户。

一种解决方法是拥有一个users集合，您可以在注册后存储所有需要的用户信息。由于您拥有帖子中的用户ID，因此将其用作users集合中每个用户的文档ID会更容易。然后，您可以使用帖子中的用户ID从users集合中获取他的文档，其中将包含他的所有详细信息。

从Firebase检索用户的displayName和个人资料图片

2 个答案: