有人知道如何在Xamarin.iOS上使用ExternalAccessory API吗？
我的Xamarin Studio版本是4.0.12（版本3），Xamarin.Android版本4.8.1，Xamarin.iOS版本6.4.5.0和Xcode是版本5.0（5A1413）我尝试了目标6.1和7.0 iPad / iPhone
我走了互联网，没有太多文件。甚至MonoTouch文档也断开了链接。
我想要的是，列出连接的蓝牙设备，然后按名称获取其中一个，然后连接到它，这样我就可以打开一个套接字并开始向它发送数据。它是一个使用串行通信的设备，是的，它具有Apple外部附件协议ID。
我试过这个：
var am = EAAccessoryManager.SharedAccessoryManager;
它只是抛出一个异常InvaidCastException。
任何线索？
谢谢！我非常感谢你的帮助。
PS：Xamarin详细信息
Xamarin Studio
Version 4.0.12 (build 3)
Installation UUID: 7348d641-ed6d-4c8a-b59a-116674e06dfd
Runtime:
Mono 3.2.0 ((no/7c7fcc7)
GTK 2.24.20
GTK# (2.12.0.0)
Package version: 302000000
[...]
Apple Developer Tools
Xcode 5.0 (3332.25)
Build 5A1413
[...]
Xamarin.iOS
Version: 6.4.5.0 (Trial Edition)
Hash: 1336a36
Branch:
Build date: 2013-10-09 11:14:45-0400
Build Information
Release ID: 400120003
Git revision: 593d7acb1cb78ceeeb482d5133cf1fe514467e39
Build date: 2013-08-07 20:30:53+0000
Xamarin addins: 25a0858b281923e666b09259ad4746b774e0a873
Operating System
Mac OS X 10.8.5
Darwin Gutembergs-MacBook-Pro.local 12.5.0 Darwin Kernel Version 12.5.0
Mon Jul 29 16:33:49 PDT 2013
root:xnu-2050.48.11~1/RELEASE_X86_64 x86_64
答案 0 :(得分：4)
虽然看起来你已经解决了这个问题，但我想我会展示一些显示基础知识的代码片段（在这种情况下连接到Sphero并将其变为绿色）：
EAAccessoryManager mgr = EAAccessoryManager.SharedAccessoryManager;
var accessories = mgr.ConnectedAccessories;
foreach(var accessory in accessories)
{
myLabel.Text = "Got me an accessory";
Console.WriteLine(accessory.ToString());
Console.WriteLine(accessory.Name);
var protocol = "com.orbotix.robotprotocol";
if(accessory.ProtocolStrings.Where(s => s == protocol).Any())
{
myLabel.Text = "Got me a Sphero";
var session = new EASession(accessory, protocol);
var outputStream = session.OutputStream;
outputStream.Delegate = new MyOutputStreamDelegate(myLabel);
outputStream.Schedule(NSRunLoop.Current, "kCFRunLoopDefaultMode");
outputStream.Open();
}
}
和
public class MyOutputStreamDelegate : NSStreamDelegate
{
UILabel label;
bool hasWritten = false;
public MyOutputStreamDelegate(UILabel label)
{
this.label = label;
}
public override void HandleEvent(NSStream theStream, NSStreamEvent streamEvent)
{
if(streamEvent == NSStreamEvent.HasSpaceAvailable && ! hasWritten)
{
//Set the color of the Sphero
var written = ((NSOutputStream)theStream).Write(new byte[] {0xFF, 0xFF, 0x02, 0x20, 0x0e, 0x05, 0x1F, 0xFF, 0x1B, 0x00, 0x91}, 11);
if(written == 11)
{
label.Text = "Sphero should be green";
}
hasWritten = true;
}
}
}
答案 1 :(得分：1)
我知道您特别询问了如何向蓝牙设备写入数据，但这只是扩展了读取数据，以及Xamarin.iOS的外部附件API的一般用途，因为没有太多文档或Xamarin样本在那里。这是使用Objective-C完成的Apple sample的松散转换。我的配件是MFi认证的微芯片阅读器。我只提供了“阅读”功能，因为我只需要我的应用程序。
创建一个继承自NSStreamDelegate的SessionController类，这会做很多管道工作。打开，关闭会话，处理来自设备的事件并读取数据。你也想在这里添加你的写法。
public class EASessionController : NSStreamDelegate
{
NSString SessionDataReceivedNotification = (NSString)"SessionDataReceivedNotification";
public static EAAccessory _accessory;
public static string _protocolString;
EASession _session;
NSMutableData _readData;
public static EASessionController SharedController()
{
EASessionController sessionController = null;
if (sessionController == null)
{
sessionController = new EASessionController();
}
return sessionController;
}
public void SetupController(EAAccessory accessory, string protocolString)
{
_accessory = accessory;
_protocolString = protocolString;
}
public bool OpenSession()
{
Console.WriteLine("opening new session");
_accessory.WeakDelegate = this;
if (_session == null)
_session = new EASession(_accessory, _protocolString);
// Open both input and output streams even if the device only makes use of one of them
_session.InputStream.Delegate = this;
_session.InputStream.Schedule(NSRunLoop.Current, NSRunLoopMode.Default);
_session.InputStream.Open();
_session.OutputStream.Delegate = this;
_session.OutputStream.Schedule(NSRunLoop.Current, NSRunLoopMode.Default);
_session.OutputStream.Open();
return (_session != null);
}
public void CloseSession()
{
_session.InputStream.Unschedule(NSRunLoop.Current, NSRunLoopMode.Default);
_session.InputStream.Delegate = null;
_session.InputStream.Close();
_session.OutputStream.Unschedule(NSRunLoop.Current, NSRunLoopMode.Default);
_session.OutputStream.Delegate = null;
_session.OutputStream.Close();
_session = null;
}
/// <summary>
/// Get Number of bytes to read into local buffer
/// </summary>
/// <returns></returns>
public nuint ReadBytesAvailable()
{
return _readData.Length;
}
/// <summary>
/// High level read method
/// </summary>
/// <param name="bytesToRead"></param>
/// <returns></returns>
public NSData ReadData(nuint bytesToRead)
{
NSData data = null;
if (_readData.Length >= bytesToRead)
{
NSRange range = new NSRange(0, (nint)bytesToRead);
data = _readData.Subdata(range);
_readData.ReplaceBytes(range, IntPtr.Zero, 0);
}
return data;
}
/// <summary>
/// Low level read method - read data while there is data and space in input buffer, then post notification to observer
/// </summary>
void ReadData()
{
nuint bufferSize = 128;
byte[] buffer = new byte[bufferSize];
while (_session.InputStream.HasBytesAvailable())
{
nint bytesRead = _session.InputStream.Read(buffer, bufferSize);
if (_readData == null)
{
_readData = new NSMutableData();
}
_readData.AppendBytes(buffer, 0, bytesRead);
Console.WriteLine(buffer);
}
// We now have our data from the device (stored in _readData), so post the notification for an observer to do something with the data
NSNotificationCenter.DefaultCenter.PostNotificationName(SessionDataReceivedNotification, this);
}
/// <summary>
/// Handle the events occurring with the external accessory
/// </summary>
/// <param name="theStream"></param>
/// <param name="streamEvent"></param>
public override void HandleEvent(NSStream theStream, NSStreamEvent streamEvent)
{
switch (streamEvent)
{
case NSStreamEvent.None:
Console.WriteLine("StreamEventNone");
break;
case NSStreamEvent.HasBytesAvailable:
Console.WriteLine("StreamEventHasBytesAvailable");
ReadData();
break;
case NSStreamEvent.HasSpaceAvailable:
Console.WriteLine("StreamEventHasSpaceAvailable");
// Do write operations to the device here
break;
case NSStreamEvent.OpenCompleted:
Console.WriteLine("StreamEventOpenCompleted");
break;
case NSStreamEvent.ErrorOccurred:
Console.WriteLine("StreamEventErroOccurred");
break;
case NSStreamEvent.EndEncountered:
Console.WriteLine("StreamEventEndEncountered");
break;
default:
Console.WriteLine("Stream present but no event");
break;
}
}
}
在我的ViewController中，它将显示我刚刚从外部附件读取的数据，我们将其全部连接起来。在ViewDidLoad中，创建观察者，以便视图知道设备何时触发了事件。还要检查我们是否已连接到正确的配件并打开会话。
public EASessionController _EASessionController;
EAAccessory[] _accessoryList;
EAAccessory _selectedAccessory;
NSString SessionDataReceivedNotification = (NSString)"SessionDataReceivedNotification";
string myDeviceProtocol = "com.my-microchip-reader.1234";
public override void ViewDidLoad()
{
base.ViewDidLoad();
NSNotificationCenter.DefaultCenter.AddObserver(EAAccessoryManager.DidConnectNotification, EADidConnect);
NSNotificationCenter.DefaultCenter.AddObserver(EAAccessoryManager.DidDisconnectNotification, EADidDisconnect);
NSNotificationCenter.DefaultCenter.AddObserver(SessionDataReceivedNotification, SessionDataReceived);
EAAccessoryManager.SharedAccessoryManager.RegisterForLocalNotifications();
_EASessionController = EASessionController.SharedController();
_accessoryList = EAAccessoryManager.SharedAccessoryManager.ConnectedAccessories;
foreach (EAAccessory acc in _accessoryList)
{
if (acc.ProtocolStrings.Contains(myDeviceProtocol))
{
// Connected to the correct accessory
_selectedAccessory = acc;
_EASessionController.SetupController(acc, myDeviceProtocol);
_EASessionController.OpenSession();
lblEAConnectionStatus.Text = acc.Name;
Console.WriteLine("Already connected via bluetooth");
}
else
{
// Not connected
}
}
}
创建DidConnect，DidDisconnect和SessionDataReceived方法。连接/断开连接时，设备名称仅在某些标签上更新，我在文本字段中显示数据。
void EADidConnect(NSNotification notification)
{
EAAccessory connectedAccessory = (EAAccessory)notification.UserInfo.ObjectForKey((NSString)"EAAccessoryKey");
Console.WriteLine("I did connect!!");
_accessoryList = EAAccessoryManager.SharedAccessoryManager.ConnectedAccessories;
// Reconnect and open the session in case the device was disconnected
foreach (EAAccessory acc in _accessoryList)
{
if (acc.ProtocolStrings.Contains(myDeviceProtocol))
{
// Connected to the correct accessory
_selectedAccessory = acc;
Console.WriteLine(_selectedAccessory.ProtocolStrings);
_EASessionController.SetupController(acc, myDeviceProtocol);
_EASessionController.OpenSession();
}
else
{
// Not connected
}
}
Console.WriteLine(connectedAccessory.Name);
// Update a label to show it's connected
lblEAConnectionStatus.Text = connectedAccessory.Name;
}
void EADidDisconnect(NSNotification notification)
{
Console.WriteLine("Accessory disconnected");
_EASessionController.CloseSession();
lblEAConnectionStatus.Text = string.Empty;
}
/// <summary>
/// Data receieved from accessory
/// </summary>
/// <param name="notification"></param>
void SessionDataReceived(NSNotification notification)
{
EASessionController sessionController = (EASessionController)notification.Object;
nuint bytesAvailable = 0;
while ((bytesAvailable = sessionController.ReadBytesAvailable()) > 0)
{
// read the data as a string
NSData data = sessionController.ReadData(bytesAvailable);
NSString chipNumber = new NSString(data, NSStringEncoding.UTF8);
// Displaying the data
txtMircochipNumber.Text = chipNumber;
}
}