如何使用线程在迅速?
dispatchOnMainThread:^{
NSLog(@"Block Executed On %s", dispatch_queue_get_label(dispatch_get_current_queue()));
}];
如何使用线程在迅速?
dispatchOnMainThread:^{
NSLog(@"Block Executed On %s", dispatch_queue_get_label(dispatch_get_current_queue()));
}];
当前回答
多用途螺纹功能
public enum QueueType {
case Main
case Background
case LowPriority
case HighPriority
var queue: DispatchQueue {
switch self {
case .Main:
return DispatchQueue.main
case .Background:
return DispatchQueue(label: "com.app.queue",
qos: .background,
target: nil)
case .LowPriority:
return DispatchQueue.global(qos: .userInitiated)
case .HighPriority:
return DispatchQueue.global(qos: .userInitiated)
}
}
}
func performOn(_ queueType: QueueType, closure: @escaping () -> Void) {
queueType.queue.async(execute: closure)
}
像这样使用它:
performOn(.Background) {
//Code
}
其他回答
最佳实践是定义一个可多次访问的可重用函数。
可重用的功能:
例如,AppDelegate.swift是一个全局函数。
func backgroundThread(_ delay: Double = 0.0, background: (() -> Void)? = nil, completion: (() -> Void)? = nil) {
dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INITIATED.value), 0)) {
background?()
let popTime = dispatch_time(DISPATCH_TIME_NOW, Int64(delay * Double(NSEC_PER_SEC)))
dispatch_after(popTime, dispatch_get_main_queue()) {
completion?()
}
}
}
注意:在Swift 2.0中替换QOS_CLASS_USER_INITIATED。使用QOS_CLASS_USER_INITIATED。rawValue相反
用法:
a .在后台运行一个进程,延迟3秒:
backgroundThread(3.0, background: {
// Your background function here
})
B.在后台运行一个进程,然后在前台运行一个补全:
backgroundThread(background: {
// Your function here to run in the background
},
completion: {
// A function to run in the foreground when the background thread is complete
})
C.延迟3秒-注意使用completion参数而不使用background参数:
backgroundThread(3.0, completion: {
// Your delayed function here to be run in the foreground
})
在我们的iOS应用中,中央调度是用来处理多任务的。
您可以使用此代码
// Using time interval
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+1) {
print("Hello World")
}
// Background thread
queue.sync {
for i in 0..<10 {
print("Hello", i)
}
}
// Main thread
for i in 20..<30 {
print("Hello", i)
}
更多信息请访问这个链接:https://www.programminghub.us/2018/07/integrate-dispatcher-in-swift.html
来自Jameson Quave的教程
斯威夫特2
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
//All stuff here
})
我真的很喜欢Dan Beaulieu的答案,但是它在Swift 2.2中不起作用,我认为我们可以避免那些讨厌的强制打开!
func backgroundThread(delay: Double = 0.0, background: (() -> Void)? = nil, completion: (() -> Void)? = nil) {
dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0)) {
background?()
if let completion = completion{
let popTime = dispatch_time(DISPATCH_TIME_NOW, Int64(delay * Double(NSEC_PER_SEC)))
dispatch_after(popTime, dispatch_get_main_queue()) {
completion()
}
}
}
}
Swift 3版本
Swift 3利用新的DispatchQueue类来管理队列和线程。要在后台线程上运行一些东西,你可以使用:
let backgroundQueue = DispatchQueue(label: "com.app.queue", qos: .background)
backgroundQueue.async {
print("Run on background thread")
}
或者如果你想在两行代码中实现:
DispatchQueue.global(qos: .background).async {
print("Run on background thread")
DispatchQueue.main.async {
print("We finished that.")
// only back on the main thread, may you access UI:
label.text = "Done."
}
}
你也可以在本教程中获得一些关于Swift 3中GDC的深入信息。