让 Async 帮你解决线程问题

线程这种东西一般封装比较深，很微观，也很考察计算机基础知识，虽然系统为我们封装的 GCD、NSOperation 已经很好用了，但是我发现了个更好用的~

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👨🏻‍💻 Github Demo

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🤖 要求

• iOS 9.0+
• Xcode 9.0+
• Swift 4

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🎨 测试 UI 什么样子？

1.展示页	2.展示页	3.展示页
常见场景列表	耗时操作场景示例	黑科技操作场景示例

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🎯 安装方法

在 iOS, 你需要在 Podfile 中添加.

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '9.0'
use_frameworks!

pod 'AsyncSwift'

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🛠 配置

耗时操作

这是应用最广泛的场景，为了避免阻塞主线程，将耗时操作放在子线程处理，然后在主线程使用处理结果。比如读取沙盒中的一些数据，然后将读取的数据展示在 UI，这个场景还有几个细分：
1.1 执行一个耗时操作后回调主线程

Async.background {
print("A: This is run on the \(qos_class_self().description) (expected \(QOS_CLASS_BACKGROUND.description))")
    sleep(2)
}.main {
    print("B: This is run on the \(qos_class_self().description) (expected \(qos_class_main().description)), after the previous block")
}

1.2 串行耗时操作

每一段子任务依赖上一个任务完成，全部完成后回调主线程：

let backgroundBlock = Async.background {
    print("This is run on the first\(qos_class_self().description) (expected \(QOS_CLASS_BACKGROUND.description))")
    sleep(2)
    
    print("This is run on the second \(qos_class_self().description) (expected \(QOS_CLASS_BACKGROUND.description))")
    sleep(2)
}
// Run other code here...
backgroundBlock.main {
    print("This is run on the \(qos_class_self().description) (expected \(qos_class_main().description)), after the previous block")
}

1.3 并发耗时操作

每一段子任务独立，所有子任务完成后回调主线程：

Async.main {
    print("This is run on the \(qos_class_self().description) (expected \(qos_class_main().description))")
    // Prints: "This is run on the Main (expected Main) count: 1 (expected 1)"
    }.userInteractive {
        print("This is run on the \(qos_class_self().description) (expected \(QOS_CLASS_USER_INTERACTIVE.description))")
        // Prints: "This is run on the Main (expected Main) count: 2 (expected 2)"
    }.userInitiated {
        print("This is run on the \(qos_class_self().description) (expected \(QOS_CLASS_USER_INITIATED.description)) ")
        // Prints: "This is run on the User Initiated (expected User Initiated) count: 3 (expected 3)"
    }.utility {
        print("This is run on the \(qos_class_self().description) (expected \(QOS_CLASS_UTILITY.description)) ")
        // Prints: "This is run on the Utility (expected Utility) count: 4 (expected 4)"
    }.background {
        print("This is run on the \(qos_class_self().description) (expected \(QOS_CLASS_BACKGROUND.description)) ")
        // Prints: "This is run on the User Interactive (expected User Interactive) count: 5 (expected 5)"
}

延时执行

延时一段时间后执行代码，一般见于打开 App 一段时间后，弹出求好评对话框。

let seconds = 3.0
Async.main(after: seconds) {
    print("Is called after 3 seconds")
}.background(after: 6.0) {
    print("At least 3.0 seconds after previous block, and 6.0 after Async code is called")
}

其他用法请见 Demo。

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😬 联系

• 微信 : WhatsXie
• 邮件 : ReverseScale@iCloud.com
• 博客 : https://reversescale.github.io