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
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
其他回答
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。
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
在Swift 4.2中,这是可行的。
import Foundation
class myThread: Thread
{
override func main() {
while(true) {
print("Running in the Thread");
Thread.sleep(forTimeInterval: 4);
}
}
}
let t = myThread();
t.start();
while(true) {
print("Main Loop");
sleep(5);
}
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()
}
}
}
}
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)
}
}
}