Currently, I am working on a project that encompasses an ASP.NET Web API (running on .NET 4.6.2) as the backend, a Web API Client Implementation PCL serving as the middleware, and Xamarin.Forms projects as the frontend. Following recent modifications to my web API, I have been encountering a recurring StackOverflowException when attempting to deserialize the JSON response within my frontend application. The issue seems to arise at this particular line of code:
result_ = JsonConvert.DeserializeObject<ObservableCollection<Employee>>(Encoding.UTF8.GetString(responseData_, 0, responseData_.Length));
During debugging sessions, it has become apparent that the program is repeatedly jumping between two key lines before triggering the overflow:
EmployeesManager.cs (located in the middleware)
private Image _image = new Image();
ImagesManager.cs (also found in the middleware)
private Employee _employee = new Employee();
Further down the line, you will find snippets of relevant code such as:
The defined models within the Web API:
public class Employee
{
public int Id { get; set; }
// Other properties omitted for brevity
public int? ImageId { get; set; }
public Image Image { get; set; }
public ICollection<Device> Devices { get; set; }
public int? TeamId { get; set; }
public Team Team { get; set; }
}
public class Image
{
[Key]
public int Id { get; set; }
[Required]
public byte[] Data { get; set; }
public int EmployeeId { get; set; }
public Employee Employee { get; set; }
}
Moreover, let's explore the models utilized in the client implementation (middleware). These were auto-generated using NSwag:
public partial class Employee : INotifyPropertyChanged
{
private int _id;
private int? _imageId;
private Image _image = new Image(); // This line contributes to the occurring Overflow
private ObservableCollection<Device> _devices;
private int? _teamId;
private Team _team = new Team();
// Omitted properties
[JsonProperty("image", Required = Required.Default, NullValueHandling = NullValueHandling.Ignore)]
public Image Image
{
get { return _image; }
set
{
if (_image != value)
{
_image = value;
RaisePropertyChanged();
}
}
}
public partial class Image : INotifyPropertyChanged
{
private int _id;
private int _employeeId;
private Employee _employee = new Employee(); // This line is related to the Stack Overflow issue
private byte[] _data;
// Omitted properties
[JsonProperty("employee", Required = Required.Default, NullValueHandling = NullValueHandling.Ignore)]
public Employee Employee
{
get { return _employee; }
set
{
if (_employee != value)
{
_employee = value;
RaisePropertyChanged();
}
}
}
The integration of the Web API client implementation with Xamarin.Forms across various platforms resulted in consistent behavior issues. Notably, iOS and UWP platforms detected the Stack Overflow error, whereas Android handled the situation by abruptly closing the application without any Exception messages during data retrieval from the Web API.
If more detailed sections of code are required for analysis, I can compile a concise package containing the requested information. Including all of the code here would severely impact readability.
Technologies employed in this setup include Newtonsoft Json.NET, Entity Framework 6, NSwag 6, and Xamarin.Forms version 2.3.2.127.