Azure IoT Hub支持AMQP,MQTT,HTTP协议。为了自定义这些协议,我们有Azure IoT协议网关。我可以在MQTT协议定制上找到好的样本。我需要一些使用Azure IoT协议网关进行基于TCP的协议自定义的示例代码。
编辑(为了得到答案):OP所要求的是使用Azure协议网关支持基于TCP的专有协议的示例。目前,IoT中心仅支持AMQP,MQTT和HTTP。虽然这些协议实际上依赖于TCP,但如果没有额外的AMQP,MQTT或HTTP层,则集线器不支持直接TCP连接。正如here所解释的,我们需要一个基于TCP的自定义协议的基本示例。
想象一个基本设备只能通过TCP在给定的IP地址/端口上发送一些专有的有效载荷:我们需要一个网关定制的例子,允许该设备将数据发送到集线器。
协议网关的当前代码设计很差,因为它严重依赖于MQTT。
也加上一些赏金。
由于所有MQTT代码,默认的协议网关示例确实有些令人困惑。协议网关通过为连接到网关的每个自定义协议设备“模拟”IoTHub连接来工作。
要从TCP设备到IoTHub设备执行此转换,首先需要代表设备连接到IoTHub。这是网关部分。以下是此IoTHubConnection的核心要点。
namespace GatewayTest
{
using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using DotNetty.Buffers;
using Microsoft.Azure.Devices.ProtocolGateway.Identity;
using Microsoft.Azure.Devices.ProtocolGateway.IotHubClient;
using Microsoft.Azure.Devices.ProtocolGateway.Messaging;
public class IoTHubConnection : IMessagingChannel<IMessage>
{
private readonly string iotHubHostName;
private readonly Func<IDeviceIdentity, Task<IMessagingServiceClient>> deviceClientFactory;
private readonly Func<string, Task> onMessage;
private IMessagingServiceClient deviceClient;
private IDeviceIdentity deviceIdentity;
public IoTHubConnection(
string iotHubHostName,
Func<IDeviceIdentity, Task<IMessagingServiceClient>> deviceClientFactory,
Func<string, Task> onMessage)
{
this.iotHubHostName = iotHubHostName;
this.deviceClientFactory = deviceClientFactory;
this.onMessage = onMessage;
}
public event EventHandler CapabilitiesChanged;
public async Task OpenAsync(string deviceId, string deviceKey)
{
this.deviceIdentity = this.GetDeviceIdentity(deviceId, deviceKey);
if (this.deviceIdentity != UnauthenticatedDeviceIdentity.Instance)
{
this.deviceClient = await this.deviceClientFactory(this.deviceIdentity);
this.deviceClient.BindMessagingChannel(this);
}
}
public async Task CloseAsync()
{
await this.deviceClient.DisposeAsync(null);
this.deviceClient = null;
}
public void Handle(IMessage message)
{
var messageBody = message.Payload.ToString(Encoding.UTF8);
this.onMessage(messageBody);
this.deviceClient.CompleteAsync(message.Id);
}
public Task SendMessage(string message)
{
var buffer = Unpooled.WrappedBuffer(Encoding.UTF8.GetBytes(message));
var deviceMessage = this.deviceClient.CreateMessage($"devices/{this.deviceIdentity.Id}/messages/events", buffer);
return this.deviceClient.SendAsync(deviceMessage);
}
protected virtual void OnCapabilitiesChanged(EventArgs e)
{
this.CapabilitiesChanged?.Invoke(this, e);
}
private IDeviceIdentity GetDeviceIdentity(string userName, string deviceKey)
{
IotHubDeviceIdentity ideviceIdentity;
if (!IotHubDeviceIdentity.TryParse($"{this.iotHubHostName}/{userName}", out ideviceIdentity))
{
return UnauthenticatedDeviceIdentity.Instance;
}
ideviceIdentity.WithDeviceKey(deviceKey);
return ideviceIdentity;
}
}
}
deviceClientFactory回调方法应该如下所示实现,并在Github的ProtocolGateway repo中的this line中实现。
deviceClientFactory = IotHubClient.PreparePoolFactory(
"IotHubConnectionString",
400,
TimeSpan.FromMinutes(3),
iotHubClientSettings,
PooledByteBufferAllocator.Default,
new ConfigurableMessageAddressConverter("TopicNameConversion"));
当Tcp设备连接到协议时,您应该创建此IoTHubConnection的实例,并将消息从设备发送到IoTHubConnection,反之亦然。下面的代码显示了如何完成此操作的非常简单的版本。
private const int BufferSize = 1024;
private byte[] buffer = new byte[BufferSize];
private IoTHubConnection ioTHubConnection;
private NetworkStream stream;
private async Task Start()
{
listener = new TcpListener(IPAddress.Any, port);
listener.Start();
var client = await listener.AcceptTcpClientAsync();
ioTHubConnection = new IoTHubConnection("IoTHubName", deviceClientFactory, OnIoTHubMessage);
stream = client.GetStream();
// Read DeviceId and DeviceKey from some sort of StartConnection-message send by the TcpClient.
await ioTHubConnection.OpenAsync("DeviceId", "DeviceKey");
stream.BeginRead(buffer, 0, BufferSize, ReadTcpStreamCallback, null);
}
private void ReadTcpStreamCallback(IAsyncResult ar)
{
var bytesRead = stream.EndRead(ar);
if (bytesRead > 0)
{
var message = System.Text.Encoding.ASCII.GetString(result);
ioTHubConnection.SendMessage(message);
// Read again.
stream.BeginRead(buffer, 0, BufferSize, ReadTcpStreamCallback, null);
}
}
private async Task OnIoTHubMessage(string message)
{
// Potentially do some translation on the IoTHub message
// and send it to the Device
var byteData = Encoding.UTF8.GetBytes(message);
stream.BeginWrite(byteData, 0, byteData.Length, SendTcpCallback, null);
}
private void SendTcpCallback(IAsyncResult ar)
{
stream.EndWrite(ar);
}