Visual Studio Code: Debug ASP.NET Application with Hot Reload

Visual Studio Code is now my favorite development tool and I've migrated all my .NET projects to Code. This article documents the steps to configure a Code launch profile for an ASP.NET Core web application.

Create project

Create a folder named dotnetcore6-web. Open it in Visual Studio Code. 

Open a terminal in the tool and initialize the project using the following command:

dotnet new web

Create a launch.json file

Navigate to Run and Debug tab:

Click link create a launch.json file. 

Select .NET 5+ and .NET Core.

A file named launch.json is created as the following screenshot shows:

Another file named tasks.json is also created:

{
    "version": "2.0.0",
    "tasks": [
        {
            "label": "build",
            "command": "dotnet",
            "type": "process",
            "args": [
                "build",
                "${workspaceFolder}/dotnetcore6-web.csproj",
                "/property:GenerateFullPaths=true",
                "/consoleloggerparameters:NoSummary"
            ],
            "problemMatcher": "$msCompile"
        },
        {
            "label": "publish",
            "command": "dotnet",
            "type": "process",
            "args": [
                "publish",
                "${workspaceFolder}/dotnetcore6-web.csproj",
                "/property:GenerateFullPaths=true",
                "/consoleloggerparameters:NoSummary"
            ],
            "problemMatcher": "$msCompile"
        },
        {
            "label": "watch",
            "command": "dotnet",
            "type": "process",
            "args": [
                "watch",
                "run",
                "--project",
                "${workspaceFolder}/dotnetcore6-web.csproj"
            ],
            "problemMatcher": "$msCompile"
        }
    ]
}

Some of the tasks will be used later.

Add hot reload launch profile

Update launch.json with the following content:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "debug-hot-reload",
            "type": "coreclr",
            "request": "launch",
            "preLaunchTask": "build",
            "program": "dotnet",
            "args": [
                "watch",
                "--project",
                ".",
                "--verbose"
            ],
            "cwd": "${workspaceFolder}",
            "stopAtEntry": false,
            "serverReadyAction": {
                "action": "openExternally",
                "pattern": "\\bNow listening on:\\s+(https?://\\S+)"
            },
            "env": {
                "ASPNETCORE_ENVIRONMENT": "Development",
                "Key": "Value"
            },
            "sourceFileMap": {
                "/Views": "${workspaceFolder}/Views"
            }
        },
        {
            "name": ".NET Core Attach",
            "type": "coreclr",
            "request": "attach"
        }
    ]
}

Task build is executed before debugging. 

Run and Debug

Now you can click debug-hot-reload to launch the debug in Run and Debug tab.

The debug window looks like the following screenshot:

If you change any code in your project, for example, adding a new view model, the debug window will reload automatically. 

Happy debugging!