Update Framework in project file

readme.md

Requires NuGet package Spectre.Console for return text.

ProjectUpdater.cs

using System.Xml.Linq;

namespace UpdateFrameworkApp.Classes;

public class ProjectUpdater
{
    public static string UpdateTargetFramework(string csprojPath, string oldFramework = "net7.0", string newFramework = "net9.0")
    {
        if (!File.Exists(csprojPath))
        {
            return $"[red]File not found:[/] {csprojPath}";
        }

        try
        {
            var doc = XDocument.Load(csprojPath);
            var targetFrameworkElement = doc.Root?.Element("PropertyGroup") ?.Element("TargetFramework");

            if (targetFrameworkElement == null)
            {
                return "[red]No <TargetFramework> element found.[/]";
            }

            if (targetFrameworkElement.Value.Trim() != oldFramework)
            {
                return $"[red]TargetFramework is not[/] [cyan]'{oldFramework}'[/],[red] found[/] [cyan]'" +
                       $"{targetFrameworkElement.Value}'[/]. [red]No changes made.[/]";
            }

            targetFrameworkElement.Value = newFramework;
            doc.Save(csprojPath);
            return $"[cyan]Updated TargetFramework to[/] '{newFramework}' [cyan]in[/] '{Path.GetFileName(csprojPath)}'.";
        }
        catch (Exception ex)
        {
            return $"Error updating file: {ex.Message}";
        }
    }
}