.net for network mailboxes get DbContext

Question

I am testing the .net core and building a small sample application using .net core + websockets to insert some data into my application. I want to store this data in a database using dbcontext.

However, I am having problems getting dbcontext in my websocket handler. So how can I create a dbcontext to use.

My Configure startup method contains the following:

...
app.Map("/ws", WSHandler.Map);
...

This is my WSHandler class, which actually does a read from an incoming connection. I need a DbContext here, which I can use to read / write from the database.

/// <summary>
/// Handler for an incoming websocket client
/// </summary>
public class WSHandler {
    /// <summary>
    /// Max size in bytes of an incoming/outgoing message
    /// </summary>
    public const int BufferSize = 4096;

    /// <summary>
    /// The socket of the current connection
    /// </summary>
    WebSocket socket;

    /// <summary>
    /// Constructor, assign socket to current instance and adds socket to ConnectedClients. 
    /// </summary>
    /// <param name="socket"></param>
    WSHandler(WebSocket socket) {
        this.socket = socket;
    }

    /// <summary>
    /// Configure app to use websockets and register handler.
    /// </summary>
    /// <param name="app"></param>
    public static void Map(IApplicationBuilder app) {
        app.UseWebSockets();
        app.Use((WSHandler.Acceptor);
    }

    /// <summary>
    /// Accept HttpContext and handles constructs instance of WSHandler.
    /// </summary>
    /// <param name="hc">The HttpContext</param>
    /// <param name="n">Task n</param>
    /// <returns></returns>
    static async Task Acceptor(HttpContext hc, Func<Task> n) {
         if (hc.WebSockets.IsWebSocketRequest == false) {
            return; 
        }

        var socket = await hc.WebSockets.AcceptWebSocketAsync();
        var h = new WSHandler(socket);
        await h.Loop();
    }

    /// <summary>
    /// Wait for incoming messages 
    /// </summary>
    /// <returns></returns>
    async Task Loop() {
        var buffer = new Byte[BufferSize];
        ArraySegment<Byte> segment = new ArraySegment<byte>(buffer);
        while (this.socket.State == WebSocketState.Open) {
            WebSocketReceiveResult result = null;
            do {
                result = await socket.ReceiveAsync(segment, CancellationToken.None);
            } while (result.EndOfMessage == false);

            // do something with message here. I want to save parse and save to database
        }

    }
}

Answer 1

, , .

HttpContext. , , , . , , , DbContext . DbContext websocket.

DbContexts. , ...

 <summary>
/// Handler for an incoming websocket client
/// </summary>
public class WSHandler {
    /// <summary>
    /// Max size in bytes of an incoming/outgoing message
    /// </summary>
    public const int BufferSize = 4096;

    /// <summary>
    /// The socket of the current connection
    /// </summary>
    WebSocket socket;

    /// <summary>
    /// The options to create DbContexts with.
    /// </summary>
    DbContextOptions<AssemblyServerContext> ctxOpts;

    /// <summary>
    /// Constructor, assign socket to current instance and adds socket to ConnectedClients. 
    /// </summary>
    /// <param name="socket"></param>
    /// <param name="ctxOpts"></param>
    WSHandler(WebSocket socket, DbContextOptions<AssemblyServerContext> ctxOpts) {
        this.ctxOpts = ctxOpts;
        this.socket = socket;
    }

    /// <summary>
    /// Configure app to use websockets and register handler.
    /// </summary>
    /// <param name="app"></param>
    public static void Map(IApplicationBuilder app) {
        app.UseWebSockets();
        app.Use((WSHandler.Acceptor);
    }

    /// <summary>
    /// Accept HttpContext and handles constructs instance of WSHandler.
    /// </summary>
    /// <param name="hc">The HttpContext</param>
    /// <param name="n">Task n</param>
    /// <returns></returns>
    static async Task Acceptor(HttpContext hc, Func<Task> n) {
         if (hc.WebSockets.IsWebSocketRequest == false) {
            return; 
        }

        var socket = await hc.WebSockets.AcceptWebSocketAsync();
        var ctxOptions = hc.RequestServices.GetService<DbContextOptions<AssemblyServerContext>>();
        var h = new WSHandler(socket, ctxOptions);
        await h.Loop();
    }

    /// <summary>
    /// Wait for incoming messages 
    /// </summary>
    /// <returns></returns>
    async Task Loop() {
        var buffer = new Byte[BufferSize];
        ArraySegment<Byte> segment = new ArraySegment<byte>(buffer);
        while (this.socket.State == WebSocketState.Open) {
            WebSocketReceiveResult result = null;
            do {
                result = await socket.ReceiveAsync(segment, CancellationToken.None);
            } while (result.EndOfMessage == false);

            // do something with message here. I want to save parse and save to database
            using (var ctx = new AssemblyServerContext(ctxOpts)) {

            }
        }

    }
}