从两个异步函数接收数据后如何执行操作?迅速
我执行 2 个 http 请求并从它们异步获取数据。接收到数据后,我需要根据它形成一个数组并重新加载表,我该怎么做?代码:
override func viewDidLoad() {
super.viewDidLoad()
ApiManager.shared.getStocks(completion: {result in
DispatchQueue.main.async {
switch result {
case .success(let stocks):
self.stocks = stocks
case .failure:
self.stocks = []
}
print(self.stocks.count)
}
})
ApiManager.shared.getDowJones (completion: { result in
DispatchQueue.main.async {
switch result {
case .success(let dowJones):
self.dowJones = dowJones
case .failure:
self.dowJones = []
}
print(self.dowJones.prefix(10))
}
})
}
回答
最合适 DispatchGroup
let g = DispatchGroup()
g.enter()
ApiManager.shared.getStocks(completion: {result in
DispatchQueue.main.async {
switch result {
case .success(let stocks):
self.stocks = stocks
case .failure:
self.stocks = []
}
g.leave()
print(self.stocks.count)
}
})
g.enter()
ApiManager.shared.getDowJones (completion: { result in
DispatchQueue.main.async {
switch result {
case .success(let dowJones):
self.dowJones = dowJones
case .failure:
self.dowJones = []
}
g.leave()
print(self.dowJones.prefix(10))
}
})
g.notify(queue:.main) {
// reload here
}