C# native host with Chrome Native Messaging

问题:

I spent a few hours today researching how to get Chrome native messaging working with a C# native host. Conceptually it was quite simple, but there were a few snags that I resolved with help (in part) from these other questions:

Native Messaging Chrome
Native messaging from chrome extension to native host written in C#
Very Slow to pass "large" amount of data from Chrome Extension to Host (written in C#)

My solution is posted below.

回答1:

Assuming the manifest is set up properly, here is a complete example for talking to a C# host using the "port" method:

using System; using System.IO; using Newtonsoft.Json; using Newtonsoft.Json.Linq;  namespace NativeMessagingHost {    class Program    {       public static void Main(string[] args)       {          JObject data;          while ((data = Read()) != null)          {             var processed = ProcessMessage(data);             Write(processed);             if (processed == "exit")             {                return;             }          }       }        public static string ProcessMessage(JObject data)       {          var message = data["text"].Value();          switch (message)          {             case "test":                return "testing!";             case "exit":                return "exit";             default:                return "echo: " + message;          }       }        public static JObject Read()       {          var stdin = Console.OpenStandardInput();          var length = 0;           var lengthBytes = new byte[4];          stdin.Read(lengthBytes, 0, 4);          length = BitConverter.ToInt32(lengthBytes, 0);           var buffer = new char[length];          using (var reader = new StreamReader(stdin))          {             while (reader.Peek() >= 0)             {                reader.Read(buffer, 0, buffer.Length);             }          }           return (JObject)JsonConvert.DeserializeObject(new string(buffer));       }        public static void Write(JToken data)       {          var json = new JObject();          json["data"] = data;           var bytes = System.Text.Encoding.UTF8.GetBytes(json.ToString(Formatting.None));           var stdout = Console.OpenStandardOutput();          stdout.WriteByte((byte)((bytes.Length >> 0) & 0xFF));          stdout.WriteByte((byte)((bytes.Length >> 8) & 0xFF));          stdout.WriteByte((byte)((bytes.Length >> 16) & 0xFF));          stdout.WriteByte((byte)((bytes.Length >> 24) & 0xFF));          stdout.Write(bytes, 0, bytes.Length);          stdout.Flush();       }    } } 

If you don't need to actively communicate with the host, using runtime.sendNativeMessage will work fine. To prevent the host from hanging, simply remove the while loop and do Read/Write once.

To test this, I used the example project provided by Google here: https://chromium.googlesource.com/chromium/src/+/master/chrome/common/extensions/docs/examples/api/nativeMessaging

Note: I'm using Json.NET to simplify the json serialization/de-serialization process.

I hope this is helpful to somebody!

文章来源: C# native host with Chrome Native Messaging