System.IO.FileNotFoundException: '找不到文件（但文件存在于项目中）

Question

I have taken a static list and added product data into a data.json inside wwwroot and data is being saved but while I'm trying to read data from the file, getting above exception. This is my controller code

public class ProductController: Controller {

    static List<ProductGeneral> productDetails = new List<ProductGeneral>();


    private IWebHostEnvironment WebHostEnvironment;
    public ProductController(IWebHostEnvironment webHostEnvironment)
    {

        WebHostEnvironment = webHostEnvironment;

    }
    public ActionResult CreateData(ProductGeneral model)
    {

        if (model != null && ModelState.IsValid )
        {
            productDetails.Add(model);
            string data = JsonConvert.SerializeObject(productDetails, Formatting.Indented);
            CreateFile(data);
            return View("ShowData", productDetails);
        }
        else
        {
            return View();
        }
    }
    public void CreateFile(string data)
    {
        string uploadDir = Path.Combine(WebHostEnvironment.WebRootPath);
        var fileName = "data.json";
        string filePath = Path.Combine(uploadDir, fileName);
        System.IO.File.WriteAllText(filePath, data);
       


    }

    public ActionResult ShowData()
    {

        //string RootPath = WebHostEnvironment.WebRootPath;
        //var JSON = System.IO.File.ReadAllText(RootPath + @"\Json\c356896b-5025-47b3-a049-662f2098be52");
        //return View(JSON);
       
            
            string RootPath = WebHostEnvironment.WebRootPath;
            var data = System.IO.File.ReadAllText(RootPath + @"data.json");
        
            if (!string.IsNullOrEmpty(data))
            {
                productDetails = JsonConvert.DeserializeObject<List<ProductGeneral>>(data);
            }
        
        return View(productDetails);
    }

        
  
    

}

Answer 1

In the ShowData() method it is necessary to use Path.Combine() to generate correct path_filename as you did in the CreateFile() :

var path = Path.Combine(WebHostEnvironment.WebRootPath, "data.json");
var data = System.IO.File.ReadAllText(path);