xcode 如何检查 dispatch_async 块是否已完成运行
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how to check an dispatch_async block has finished running
提问by jimbob
So basically I need to be able to run a segue after a block has finished running. I have a block which does some JSON stuff and I need to know when that has finished running.
所以基本上我需要能够在块完成运行后运行 segue。我有一个执行一些 JSON 内容的块，我需要知道它何时完成运行。
I have a queue which I have called json_queue.
我有一个队列，我称之为 json_queue。
jsonQueue = dispatch_queue_create("com.jaboston.jsonQueue", NULL);
I then have a dispatch_async block with this syntax:
然后我有一个具有以下语法的 dispatch_async 块：
dispatch_async(jsonQueue, ^{
[self doSomeJSON];
[self performSegueWithIdentifier:@"modaltomenu" sender:self];
});
It wont let me perform the line: "[self performSegueWithIdentifier:@"modaltomenu" sender:self];"
它不会让我执行以下行：“[self performSegueWithIdentifier:@"modaltomenu" sender:self];”
Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...
试图从主线程或 web 线程以外的线程获取 web 锁。这可能是从辅助线程调用 UIKit 的结果。现在崩溃...
Where can I check to find out when the thread has done its dirty work so i can call the segue?
我在哪里可以检查以找出线程何时完成其肮脏的工作，以便我可以调用 segue？
Thankyou lovely people.
谢谢可爱的人。
PS: beer and ups and teddy bears and flowers to whoever can help <3.
PS：啤酒和起居室以及泰迪熊和鲜花给任何可以帮助的人<3。
回答by Johnnywho
You should call UI methods on main thread only. Try to dispatch performSegueWithIdentifier: on main queue:
您应该只在主线程上调用 UI 方法。尝试在主队列上调度 performSegueWithIdentifier:
dispatch_async(jsonQueue, ^{
[self doSomeJSON];
dispatch_sync(dispatch_get_main_queue(), ^{
[self performSegueWithIdentifier:@"modaltomenu" sender:self];
});
});
回答by shabbirv
dispatch_async(jsonQueue, ^{
[self doSomeJSON];
dispatch_async(dispatch_get_main_queue(), ^{
[self performSegueWithIdentifier:@"modaltomenu" sender:self];
//Finished with async block
});
});
