How can I add blazor server-sdie into an exists asp.net core project? RRS feed

  • Question

  • User1052024640 posted

    I have made a website by asp.net core 3.1 before.

    Now I wanna add a feature of 'contact us'.

    After the users input their name/phone and click the submit button, the blazor server-side will send an e-mail of the user information above to my mailbox.

    In spite, I can achieve this by Ajax, but now I want to do this by Blazor server-side.

    I don't want to migrate the whole project to Blazor server-side for this feature only available on some page but not all the pages.

    In my opinion, I will add blazor server-side into the asp.net core project which is existed.

    I tried this by myself by adding the services.AddServerSideBlazor(); in ConfigureServices and adding the MapBlazorHub to UseEndpoints in Configure.

    I only add a h3 element to the component of Blazor server-side and add the it to an existing page like this:

    <component type="typeof(Project.Pages.Contact)" render-mode="ServerPrerendered" />

    After I ran the project, it reports these errors in Chrome DevTools:

    [2020-03-26T09:01:16.249Z] Error: Failed to complete negotiation with the server: Error
    [2020-03-26T09:01:16.249Z] Error: Failed to start the connection: Error
    [2020-03-26T09:01:16.250Z] Error: Error
    Uncaught (in promise) Error: Cannot send data if the connection is not in the 'Connected' State.
    at e.send (blazor.server.js:1)
    at e.sendMessage (blazor.server.js:1)
    at e.sendWithProtocol (blazor.server.js:1)
    at blazor.server.js:1
    at new Promise (<anonymous>)
    at e.invoke (blazor.server.js:1)
    at e.<anonymous> (blazor.server.js:15)
    at blazor.server.js:15
    at Object.next (blazor.server.js:15)
    at blazor.server.js:15

    I googled and found it seems the SignalR of the project did not start correctly.

    How can I solve this? Is there any tutorial about this? Thank you.

    Thursday, March 26, 2020 9:10 AM


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