我在网上搜索过，但没有找到与我的问题相关的答案。希望有人能帮我。提前谢谢！
这是一个Firebase observeEvent函数。
ref.child("path").observeSingleEvent(of: .value, with: { (snapshot) in
// here I have a for loop
for (_, dict) snapshot.value as! NSDictionary {
// do something...
//
// here I would like to do some UI updating, like a progress bar, or just as simple as update the text in a label
label.text = "an object fetched."
}
// I used to do some UI update here, and it works, like tableview.reloadData(), but this time I would like the UI updating happen in that for loop
}) { (error) in
print(error.localizedDescription)
}
有人能帮我一下吗？我试过了
DispatchQueue.main.async {
// UI update here but it doesn't work
}
希望有人能帮助我，非常感谢！
最佳答案
Firebase事件回调在主/UI线程上触发。您不需要遍历分派队列，只需从回调中更新UI即可。