将值设置为模型实例 - ArgumentOutOfRangeException

Question

我在为模型实例设置值时遇到错误

控制器

var operatingDTO = new List<OperatingDTO>();

      operatingDTO[0].Id = 1;

型号

public class OperatingDTO
    {
        public int Id { get; set; }
    }

错误

'operatingDTO[0].Id' threw an exception of type 'System.ArgumentOutOfRangeException'

Answer 1

您应该实例化该元素，然后将其添加到列表中。有一个完整的指南：Object and Collection Initializers (C# Programming Guide).

C# lets you instantiate an object or collection and perform member assignments in a single statement.

替换为

var operatingDTO = new List<OperatingDTO>();
operatingDTO.Add(new OperatingDTO { Id = 0 });

甚至

var operatingDTO = new List<OperatingDTO> { new OperatingDTO { Id = 0 } };

Set value to model instance - ArgumentOutOfRangeException