.NET Core Cross-Platform IoT Development: Connect to Alibaba Cloud IOT (Part One)

2019年12月15日 3719点热度 0人点赞 3条评论

内容目录

Series Tutorial Directory

(1) Connecting to Alibaba Cloud IOT

(2) Setting Up Delegated Events

(3) Reporting Properties

(4) SDK Documentation: Properties, Methods, Delegates, Classes

http://pan.whuanle.cn/index.php?dir=uploads/阿里云IOT/AliIOTXFclient-dll类库&response

Download the three libraries and include them in the header to use.

using AliIOTXFClient;

Example download link

http://pan.whuanle.cn/index.php?dir=uploads/阿里云IOT/demo示例

This chapter uses the example AliIOTXF.One

II. Creating Product Devices on Alibaba Cloud IOT

Open the address https://iot.console.aliyun.com/product

Creating a Product

Choose node type as device, non-gateway, because it directly connects to devices with network capabilities. Transparent transmission requires writing JS parsing scripts. Alink Json is convenient, less prone to errors, and easier to understand. ID² provides bidirectional identity authentication capability but comes at a cost.

Creating Devices

After successful creation, remember to use "Copy" to store it in a notepad or similar. (It doesn't matter if you save it, you can copy it later)

Attached is the documentation for creating products on Alibaba Cloud https://help.aliyun.com/document_detail/73705.html?spm=a2c4g.11174283.6.553.3a8b1668QRyRs7

Devices after creation

III. Creating Projects, Connecting to Alibaba Cloud

Create a .NET Core project of your choice, include the three DLLs, remember to select "Copy to local".

Header Inclusion

using AliIOTXFClient;

Creating Connection Client

Copy the content from "Copy" or go to the console--Specific Device to copy ProductKey and DeviceName.

XFMQTT client = new XFMQTT(ProductKey, DeviceName);　　// Create connection object

Initializing Configuration

Copy DeviceSecret from the console, the Region ID refers to the region, which you can see at the top-left corner of the console, click View Alibaba Cloud IOT Regions, and copy the corresponding Region ID. For example, mine is Huadong 2, corresponding to cn-shanghai.

client.Init(DeviceSecret, Region ID);　　// Initialize client

Adding Topics to Subscribe

Only Topics with “subscription” permissions can be subscribed. Also, only .../user/... series belong to standard Topics. We'll discuss this later, see the picture.

update, update/error, get are default Topics.

We create custom Topics, click the corresponding "product" -- view Topic class list, "Custom Topic Class"

Add two custom Topics

In the project code

            // Topics to subscribe
            string[] topic = { client.CombineHeadTopic("PubData") };

To subscribe to multiple Topics, just add them inside. The client.CombineHeadTopic() method can help generate the complete Topic based on the Topic name.

Of course, you can also directly

string[] topic = { "/a1BiPoNawLI/${deviceName}/user/PubData" };

Multiple Topics string[] topic = { top1, top2.,,,, };

Binding Event Delegates

In connecting to the server, receiving Topics, publishing Topics, reporting properties, service calls, etc., there are corresponding delegates.

We use the default delegated events here, and will gradually customize them later.

            // Use default delegated events
            client.UseDefaultEventHandler();

Starting Connection to IOT Server

            // Connect to server
            client.ConnectMqtt(topic);

Don't forget to add a line Console.ReadKey();

Complete Code

            // Create connection object
            XFMQTT client = new XFMQTT("a1BiPoNawLI", "Raspberry");
            // Initialize client configuration
            client.Init("2NOaBeqXcIzLQEhlJFEfKbWeug0o3m0c", "cn-shanghai");
            // Topics to subscribe
            string[] topic = { client.CombineHeadTopic("PubData") };
        </span><span style="color: #008000;">//</span><span style="color: #008000;"> Use default delegated events</span>

            client.UseDefaultEventHandler();
        </span><span style="color: #008000;">//</span><span style="color: #008000;"> Connect to server</span>

            client.ConnectMqtt(topic);
        Console.ReadKey();</span></pre>

The steps to create a general connection client have been completed, run the program.

IV. Subscribing to Topics and Publishing Topics

After running the program, open the console -- device list, you will find

Sending Topics

Open the device, find PubData in the Topic list, click "Publish", enter any characters (Chinese may get garbled), and check if the client receives the content.

Note: Only Topics with subscription permissions can send data to the device.

On the device, only by setting subscription to this Topic, can it receive this Topic when publishing messages from the console. Browse through more Topics in the console, try publishing them to find out.

Publishing Topics

The above steps achieved connecting to the IOT platform and subscribing to Topics. This way, you can receive server push or data. Multiple Topics can be subscribed to, and the server can successfully send to the client devices based on Topics set in the client. Below is a demonstration of how to publish data content to the server.

Add the following to the end of the code

           while (true)
            {    
                string str=Console.ReadLine();
            </span><span style="color: #008000;">//</span><span style="color: #008000;"> Push content to a specific Topic</span>
            client.Subscribe(client.CombineHeadTopic(<span style="color: #800000;">"</span><span style="color: #800000;">SubData</span><span style="color: #800000;">"</span><span style="color: #000000;">),str);
        }</span></pre>

SubData is the Topic we want to push to.

。

The complete code is as follows (please replace the corresponding contents of {***}), with the added code highlighted in red:

            // Create connection object
            XFMQTT client = new XFMQTT("{*Product Name*}", "{*Device Name*}");
            // Initialize client configuration
            client.Init("{*Key*}", "{*cn-shanghai*}");
            // Topic to subscribe
            string[] topic = { client.CombineHeadTopic("PubData") };
        </span><span style="color: #008000;">//</span><span style="color: #008000;"> Use default delegate events</span>

            client.UseDefaultEventHandler();
        </span><span style="color: #008000;">//</span><span style="color: #008000;"> Connect to the server</span>

            client.ConnectMqtt(topic);
        </span><strong><span style="color: #ff0000;">while (true)
        {    
            string str=Console.ReadLine();

            // Push content to specific Topic
            client.Subscribe(client.CombineHeadTopic("SubData"</span></strong><span style="color: #000000;"><strong><span style="color: #ff0000;">),str);
        }</span></strong>

        Console.ReadKey();</span></pre>