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
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
})
其他回答
你必须将你想要在后台运行的更改与你想要在UI上运行的更新分开:
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
// do your task
dispatch_async(dispatch_get_main_queue()) {
// update some UI
}
}
下面的代码是否有缺点(当需要启动前台屏幕之后)?
import Foundation
import UIKit
class TestTimeDelay {
static var connected:Bool = false
static var counter:Int = 0
static func showAfterDelayControl(uiViewController:UIViewController) {
NSLog("TestTimeDelay", "showAfterDelayControl")
}
static func tryReconnect() -> Bool {
counter += 1
NSLog("TestTimeDelay", "Counter:\(counter)")
return counter > 4
}
static func waitOnConnectWithDelay(milliseconds:Int, uiViewController: UIViewController) {
DispatchQueue.global(qos: .background).async {
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + DispatchTimeInterval.milliseconds(milliseconds), execute: {
waitOnConnect(uiViewController: uiViewController)
})
}
}
static func waitOnConnect(uiViewController:UIViewController) {
connected = tryReconnect()
if connected {
showAfterDelayControl(uiViewController: uiViewController)
}
else {
waitOnConnectWithDelay(milliseconds: 200, uiViewController:uiViewController)
}
}
}
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
})
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
Swift 3.0 +
在Swift 3.0中,很多东西都被现代化了。在后台队列上运行一些东西看起来像这样:
DispatchQueue.global(qos: .userInitiated).async {
print("This is run on a background queue")
DispatchQueue.main.async {
print("This is run on the main queue, after the previous code in outer block")
}
}
Swift 1.2到2.3
let qualityOfServiceClass = QOS_CLASS_USER_INITIATED
let backgroundQueue = dispatch_get_global_queue(qualityOfServiceClass, 0)
dispatch_async(backgroundQueue, {
print("This is run on a background queue")
dispatch_async(dispatch_get_main_queue(), { () -> Void in
print("This is run on the main queue, after the previous code in outer block")
})
})
Pre Swift 1.2 -已知问题
从Swift 1.1开始,苹果在没有做一些修改的情况下不支持上述语法。传递qos_class_user_initialized实际上不起作用,而是使用Int(qos_class_user_initialized .value)。
有关更多信息,请参阅apple文档