swift - 元磨损 : CLI application on MACOSX

Question

我正在尝试按照 MetaWear 指南启动示例应用程序，位于 h ere .我很快遇到的问题是我遇到了意外崩溃。这是我的代码的结构

:

最后，我的 Podfile 包含以下内容:

platform :osx, '10.12.6'

target 'meta-wear' do
    use_frameworks!

    pod 'MetaWear', '~> 2.9'
end

当我运行应用程序时，我在第一张图片的第 5 行收到如下线程异常:

Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)

虽然我当然是新的 Swift 开发人员(菜鸟)，但我不知道为什么我无法复制他们的指南。

Xcode:9.0 macOS Sierra 版本 10.12.6(这是我要运行此命令行应用程序的地方)

添加无限循环后更新

我更新了 main.swift 类以实现以下内容:

import Foundation

let runLoop = RunLoop.current;
let distantFuture = Date.distantFuture;

print("### we are in the create");
let starter = MetaWearStarter();
print("### we are after the create");

while (runLoop.run(mode: RunLoopMode.defaultRunLoopMode, before:    distantFuture)){
    print("### listening for a metawear device");
}

我创建了一个名为 MetaWearStarter.swift 的类，如下所示:

import Foundation

import MetaWear

class MetaWearStarter : NSObject {

    override init() {
        super.init();
        print("### we are in the init");
        startConnection();
    }

    func startConnection() {
        print("##### connection call was made");
        let manager = MBLMetaWearManager.shared();
        maanger.startScanForMetaWears() { array in
        print("### connection scan was complete")    
        // Hooray! We found a MetaWear board, so stop scanning for more
            MBLMetaWearManager.shared().stopScan()
            // Connect to the board we found
            if let device = array.first {
                device.connectAsync().success() { _ in
                    print("#### we connected to a device");
                    }.failure() { error in
                        print("### unable to connect");
                }
            }
        }
    }

}

我在这一行得到了之前的错误:

let manager = MBLMetaWearManager.shared();

而且我的输出永远不会超过那条线:

### we are in the create
### we are in the init
##### connection call was made

Answer 1

让runloop保持运行的无限循环不是一个好习惯。

向您的类添加完成处理程序并在完成时停止运行循环。

在 CLI 中处理运行循环的常用方法是这样的:

import Foundation
import MetaWear

class MetaWearStarter  {

    let manager = MBLMetaWearManager.shared()

    func startConnection(completion: @escaping (String)->()) {
        print("##### connection call was made");
        manager.startScanForMetaWears() { array in
            print("### connection scan was complete")
            // Hooray! We found a MetaWear board, so stop scanning for more
            manager.stopScan()
            // Connect to the board we found
            if let device = array.first {
                device.connectAsync().success() { _ in
                    completion("#### we connected to a device")
                    }.failure() { error in
                        completion("### unable to connect, error: \(error.localizedDescription)")
                }
            } else {
                completion("#### no device found")
            }
        }
    }
}

let starter = MetaWearStarter()
let runLoop = RunLoop.current
starter.startConnection { (result) in
    print(result)
    CFRunLoopStop(runLoop.getCFRunLoop())
}

runLoop.run()
exit(EXIT_SUCCESS)