Asp.net-core – How to watch for file changes “dotnet watch” with Visual Studio ASP.NET Core

asp.net-corednxkestrel-http-server

I am using Visual Studio with ASP.NET Core and run the website using just F5 or Ctrl+F5 (not using the command line directly). I would like to use the "dotnet watch" functionality to make sure all changes are picked up on the fly to avoid starting the server again. It seems that with the command line you would use "dotnet watch run" for this, but Visual Studio uses launchSettings.json and does it behind the scenes if I understand it correctly.

How can I wire up "dotnet watch" there?

Best Answer

If you want to use ASP.NET 2.x or 3.x you need to change it a bit.

  • The watch tool is a global tool now and you don't need to add it as a reference any longer

  • The syntax is slightly different

    "Watch": {
  "executablePath": "dotnet.exe",
  "workingDirectory": "$(ProjectDir)",
  "commandLineArgs": "watch run",
  "launchBrowser": true,
  "launchUrl": "http://localhost:5000/",
  "environmentVariables": {
    "ASPNETCORE_ENVIRONMENT": "Development"
  }
}

For .Net 5 & 6

In VisualStudio 2019

  1. Go to Tools > ⚙ Options > Projects and Solutions > ASP .NET Core
  2. Select Auto build and refresh browser after saving changes in Auto build and refresh option
  3. Press Ctrl + F5 (Start Without Debugging) IMPORTANT: Only works if run without debbuging

Otherwise add this to your launchSettings.json:

{
  "iisSettings": {
    ...
  },
  "profiles": {
    ... ,

    "Watch": {
      "commandName": "Executable",
      "executablePath": "dotnet.exe",
      "workingDirectory": "$(ProjectDir)",
      "commandLineArgs": "watch run"
    }

  }
}

The automatically generated profile with "commandName":"Project" has all the other properties needed: launchBrowser, applicationUrl, environmentVariables, dotnetRunMessages and hotReloadProfile. Any modifications should be made there.

Corresponding Blog-Post from Juan Cruz Fiant: https://dev.to/juxant/auto-refresh-with-dotnet-watch-for-asp-net-core-projects-20no

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