System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Int32'.

Question

public async Task UpdateEmployeeAsync(int id, Employee model)

{

  var employeee = await _appDbContext.Employees.FindAsync(id);

  if (employeee == null)

  {

      throw new Exception("Employee not found");

  }

  employeee.Name = model.Name;

  employeee.Phone = model.Phone;

  employeee.Age = model.Age;

 

  await _appDbContext.SaveChangesAsync();

}

namespace emp_curd.Data

{

public class Employee

{

    public int Id { get; set; }

    public string Name { get; set; }

    public string Email { get; set; }

    public string Phone { get; set; }

    public int Age { get; set; }

    //public object salery { get;  set; }

}

}

Answer 1

You don’t specify the line number, but I would guess model.Age is a string.

Answer 2

Hi @hammad tahir,

According to the error message , it facing the error when saving the new employee. The reason why you face this error is you pass the wrong type's model.Age to the Age.

I suggest you could recheck the model to make sure it is the right int type.

More details, you could refer to below codes:

  
        var employee = await _appDbContext.Employees.FindAsync(id);
        if (employee == null)
        {
            throw new Exception("Employee not found");
        }
        // Validate and parse Age
        if (!int.TryParse(model.Age, out int parsedAge))
        {
            throw new InvalidCastException("Age is not a valid integer");
        }
        employee.Name = model.Name;
        employee.Phone = model.Phone;
        employee.Age = parsedAge;
        await _appDbContext.SaveChangesAsync();
    
   

This will directly throw the error if the Age is not a valid int type value.

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