如何在Swift 3中编写完成处理程序? [英] How do you write a completion handler in Swift 3?
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问题描述
我想知道如何为在Swift 3中创建的函数创建完成处理程序. 这就是我在更新到Swift 3之前就完成功能的方式.
I was wondering how to make a completion handler for a function I'm creating in Swift 3. This is how I did my function right before I updated to Swift 3:
func Logout(completionHandler: (success: Bool) -> ()) {
backendless.userService.logout(
{ ( user : AnyObject!) -> () in
print("User logged out.")
completionHandler(success: true)
},
error: { ( fault : Fault!) -> () in
print("Server reported an error: \(fault)")
completionHandler(success: false)
})}
但是现在我无法找出目前可行的最佳方法.
But now I can't figure out the best approach that works right now.
推荐答案
在Swift 3中,闭包中的函数参数标签不见了.
In Swift 3 the function parameter labels in closures are gone.
删除所有出现的success:
并添加@escaping
Remove all occurrences of success:
and add @escaping
func Logout(completionHandler:@escaping (Bool) -> ()) {
backendless?.userService.logout(
{ user in
print("User logged out.")
completionHandler(true)
},
error: { fault in
print("Server reported an error: \(fault)")
completionHandler(false)
})
}
并使用它
Logout() { success in
print(success)
}
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