分享程序员开发的那些事...
更新时间：2022-12-29 18:09:45
您不能将异步任务中的某些内容作为返回值返回。
You cannot return something from an asynchronous task as a return value.
不要等待，请使用完成处理程序：
Do not wait, use a completion handler:
用
Replace the signature of the method (the name is supposed to start with a lowercase letter) with
func checkUsernamePassword(username: String, code: String, completion: @escaping (Bool)->() ) {
删除行 var validCredentials = false 和 return validCredentials
用 validCredentials = false >完成（错误）和 validCredentials = true 完成（true）。
Replace all occurrences of validCredentials = false with completion(false) and
validCredentials = true with completion(true).
调用方法
checkUsernamePassword(username: "Foo", code: "Baz") { isValid in
print(isValid)
// do something with the returned Bool
DispatchQueue.main.async {
// update UI
}
}