我如何添加一个加载圆形图标,因为它需要时间从 firestore 获取数据?
how do i add a loading circular icon as it takes time to fetch data from firestore?
I want to show a loading button until it loads all the list items from firestore.
return StreamBuilder(
stream: Firestore.instance.collection(uid).snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemBuilder: (ctx, index) {
return FavItem(
uid: snapshot.data.documents[index]['uid'],
id: snapshot.data.documents[index]['id'],
,
);
},
itemCount: snapshot.data.documents.length,
试试这个:
builder: (context, snapshot) {
if (!snapshot.hasData) {
return CircularProgressIndicator();
}
return ListView.builder(itemBuilder: (ctx, index) {
return FavItem(
uid: snapshot.data.documents[index]['uid'],
id: snapshot.data.documents[index]['id'],
);
});
}
如果还没有数据,这应该显示一个循环加载微调器(可自定义),否则它将显示 FavItem 列表。
CircularProgressIndicator 可能就是您要找的东西。
StreamBuilder(
stream: Firestore.instance.collection(uid).snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return ...;
}
if (snapshot.hasError) {
return Text(snapshot.error.toString());
}
return CircularProgressIndicator();
},
);
声明布尔变量
bool loading = false;
当api函数启动时,setState,
bool loading = true;
api函数结束,setState,
bool loading = false;
内部小部件,检查是否
!loading ? Your widget : Center(
Child:CirculatProgressIndicator();
)
I want to show a loading button until it loads all the list items from firestore.
return StreamBuilder(
stream: Firestore.instance.collection(uid).snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemBuilder: (ctx, index) {
return FavItem(
uid: snapshot.data.documents[index]['uid'],
id: snapshot.data.documents[index]['id'],
,
);
},
itemCount: snapshot.data.documents.length,
试试这个:
builder: (context, snapshot) {
if (!snapshot.hasData) {
return CircularProgressIndicator();
}
return ListView.builder(itemBuilder: (ctx, index) {
return FavItem(
uid: snapshot.data.documents[index]['uid'],
id: snapshot.data.documents[index]['id'],
);
});
}
如果还没有数据,这应该显示一个循环加载微调器(可自定义),否则它将显示 FavItem 列表。
CircularProgressIndicator 可能就是您要找的东西。
StreamBuilder(
stream: Firestore.instance.collection(uid).snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return ...;
}
if (snapshot.hasError) {
return Text(snapshot.error.toString());
}
return CircularProgressIndicator();
},
);
声明布尔变量
bool loading = false;
当api函数启动时,setState,
bool loading = true;
api函数结束,setState,
bool loading = false;
内部小部件,检查是否
!loading ? Your widget : Center(
Child:CirculatProgressIndicator();
)