代码仅在DispatchQueue.main.async块内有效,为什么? [英]Code only works within a DispatchQueue.main.async block, why?
呈现MFMessageComposeViewController / Understanding DispatchQueue.main.async [英]Presenting MFMessageComposeViewController/Understanding DispatchQueue.main.async
DispatchQueue.main.async 和 DispatchQueue.main.sync 的区别 [英]Difference between DispatchQueue.main.async and DispatchQueue.main.sync
为什么即使在主线程上也需要使用 DispatchQueue.main.async 设置 UIImageView.image [英]Why does UIImageView.image need to be set using a DispatchQueue.main.async even on the main thread