C#实体类null自动转空字符串
using System.ComponentModel.DataAnnotations;
[DisplayFormat(ConvertEmptyStringToNull = false)]
public string yptype { set; get; }
using System.ComponentModel.DataAnnotations;
[DisplayFormat(ConvertEmptyStringToNull = false)]
public string yptype { set; get; }来源:https://www.cnblogs.com/niunan/p/11758144.html