如何使用 lambda 表达式访问正确的数据类型？

Posted 2023-02-16

【中文标题】如何使用 lambda 表达式访问正确的数据类型？

【英文标题】：How to use lambda expression to access correct data type?

【发布时间】：2021-12-21 23:10:50

【问题描述】：

我正在使用 lambda 表达式来访问具有数据类型的值，但问题是我的本地数据库上的 Time 数据类型为 Time(7) 并使用实体框架。在我的模型中，此数据类型定义为 DateTime。

我现在如何访问这种数据类型？

这是我的代码：

public List GetIncident_Details()

    Entities incident = new Entities();
    List result = new List();

    var c_incident = incident.Incident_Template.Select(c => c).ToList();

    if (c_incident != null && c_incident.Count() > 0)
    
        foreach (var cData in c_incident)
        
            Incident_DropDown model = new Incident_DropDown();
            model.Title = cData.Title;
            model.Description = cData.Description;
            model.Date_Occurred = cData.Date_Occurred;

            // How do I change this to have access? 
            // It's complaining about the data type object being set to a string?
            model.Time = cData.Time; 
            model.Assignment_Group = cData.Assignment_Group;
            model.Reported_CI = cData.Reported_CI;

            result.Add(model);
        
    

    return result;


public class Incident_DropDown

    public string Title  get; set; 
    public string Description  get; set; 
    public string Date_Occurred  get; set; 
    public DateTime Time  get; set;  // Time
    public string Assignment_Group  get; set; 
    public string Reported_CI  get; set; 

【问题讨论】：

如果DateTime，您是否尝试使用TimeSpan？

@AlexyRumnyantsev 没有

【参考方案1】：

从@alexey-rumyantsev 那里得到了一些建议，然后不得不通过询问模型数据类型的时间来测试我的代码，它是日期时间，然后更改为时间跨度。在测试此数据类型时，与我的本地数据库记录进行比较，并且在调试时传递了正确的值。 // 模型名称

public class Incident_DropDown
    
        public string Title  get; set; 


        public string Description  get; set; 


        public string Date_Occured  get; set; 

        public TimeSpan Time  get; set;  // had to change to work

        public string Assignment_Group  get; set; 


        public string Reported_CI  get; set; 

    

// Controller
   public List<Incident_DropDown> GetIncident_Details()
        
            Entities incident = new Entities();
            List<Incident_DropDown> result = new List<Incident_DropDown>();


            var c_incident = incident.Incident_Template.Select(c => c).ToList();
            if (c_incident != null && c_incident.Count() > 0)
            
                foreach (var cData in c_incident)
                
                    Incident_DropDown model = new Incident_DropDown();
                    model.Title = cData.Title;
                    model.Description = cData.Description;
                    model.Date_Occured = cData.Date_Occured;
                    model.Time = cData.Time; // This here enable to pass correct time as per database record
                    model.Assignment_Group = cData.Assignment_Group;
                    model.Reported_CI = cData.Reported_CI;


                    result.Add(model);
                
            
            return result;