MetaWear：在MACOSX上的CLI应用程序

Question

我试图按照MetaWear指南启动示例应用程序，位于h ere。我正在迅速遇到的问题是，我正在发生意想不到的崩溃。这里是我的代码是如何组织的

：

最后，我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，我得到一个线程异常如下在第一张图片的第5行：

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

虽然我当然是一个新的Swift开发人员（noob），但我不知道为什么我无法重现他们的指南。

的Xcode 9.0 塞拉利昂的MacOS版本10.12.6，（这里我想运行此命令行应用程序）添加无限循环

我更新了main.swift课后

更新到ahve如下：

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"); 
       } 
      } 
     } 
    } 

} 

我得到这一行以前的错误：

let manager = MBLMetaWearManager.shared(); 

而且我的输出永远不会使得过去该行：

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

Answer 1

无限循环，以保持runloop运行的是不是一个很好的习惯。

向您的课程添加完成处理程序，并在完成时停止runloop。

通常的方式来处理在命令行运行循环是这样的：

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)