无法创建和填充列表类型 System.Collections.ICollection

Question

确切的错误是Cannot create and populate list type System.Collections.ICollection. Path'[0].assocPosition.assocJobtitle.employees''

我有这个方法

public static ArrayList Get<T>(string url)
{
    using (var response = _httpClient.GetAsync(baseUrl + url).Result)
    {
        if (response.IsSuccessStatusCode)
        {
            var customerJsonString = response.Content.ReadAsStringAsync().Result;
            var list = JsonConvert.DeserializeObject<List<T>>(customerJsonString);
            var arrayList = new ArrayList(list.Count);
            foreach (T item in list)
            {
                arrayList.Add(item);
            }
            return arrayList;
        }
    }
    return null;
}

在放置断点后我发现问题在于对象没有正确反序列化。

public static ArrayList EmployeeAssignmentFinder_FindAll()
{
    return HttpCaller.Get<EmployeeAssignment>("WorkflowEngine/EmployeeAssignmentFinder_FindAll");
}

控制器内部的HttpGet：

[HttpGet("WorkflowEngine/EmployeeAssignmentFinder_FindAll")]
        public IActionResult WorkflowEngineEmployeeAssignmentFinder_FindAll()
{
    return Ok(_engine.VC.EmployeeAssignmentFinder_FindAll());
}

EmployeeAssignment 类有内部：

private Position m_Position;
public Position AssocPosition 
{
    get { return m_Position; }
    set { m_Position = value; }
}

职位类有内部：

private Jobtitle m_AssocJobtitle;
public Jobtitle AssocJobtitle 
{
    get { return m_AssocJobtitle; }
    set { m_AssocJobtitle = value; }
}

而 Jobtitle 类有里面：

private ICollection m_Employees;
public ICollection Employees
{
    get{ return m_Employees; }
    set { m_Employees = value;}
}

从ICollection 到ArrayList 可能存在冲突。

Answer 1

尝试用 T 的 ICollection 替换 ICollection，因为最后一个被 EF 使用。

private ICollection<Employee> m_Employees
public ICollection<Employee> Employees
{
   get { return m_Employees; }
   set { m_Employees = value; }
}

恕我直言，您应该使用 List 而不是 ArrayList，因为它已经是 net 5+，而不是 net 1.O

public static List<T> Get<T>(string url)
{
    using (var response = _httpClient.GetAsync(baseUrl + url).Result)
    {
        if (response.IsSuccessStatusCode)
        {
            var customerJsonString = response.Content.ReadAsStringAsync().Result;
            return JsonConvert.DeserializeObject<List<T>>(customerJsonString);
        
        }
    }
    return null;
}

public static List<EmployeeAssignment> EmployeeAssignmentFinder_FindAll()
{
   return HttpCaller.Get<EmployeeAssignment>("WorkflowEngine/EmployeeAssignmentFinder_FindAll");
}