Question

我在MVC项目中有一个存储活动的模型。我需要显示开始时间和结束时间之间的时差。这是我的模型课：

[Table("DailyCrewActivity")]
public partial class DailyCrewActivity
{
    [Key]
    public int id { get; set; }

    [Display(Name = "Crew Name")]
    [ForeignKey("DailyCrew")]
    public int daily_crew_id { get; set; }

    [Display(Name = "Task Number")]
    [ForeignKey("ContractTask")]
    public int contract_task_id { get; set; }

    [Display(Name = "Activity Date")]
    [DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime activity_date { get; set; }

    [Required]
    [StringLength(50)]
    [Display(Name = "Activity Code")]
    public string activity_code { get; set; }

    [Display(Name = "Start Time")]
    [DisplayFormat(DataFormatString = "{0:hh:mm}")]
    public string activity_start { get; set; }

    [Display(Name = "End Time")]
    [DisplayFormat(DataFormatString = "{0:hh:mm}")]
    public string activity_end { get; set; }

    [NotMapped]
    [Display(Name = "Hours")]
    [DisplayFormat(DataFormatString = "{0:#.##}")]
    public decimal ElapsedTime
    {
        get
        {
            decimal duration = 0;
            if (String.IsNullOrEmpty(activity_start) && String.IsNullOrEmpty(activity_end))
            {

                TimeSpan spanStart;
                TimeSpan spanEnd;
                if (TimeSpan.TryParse(activity_start, out spanStart) && TimeSpan.TryParse(activity_end, out spanEnd))
                {
                    duration = Convert.ToDecimal(spanEnd - spanStart);
                }

            }
            return duration;
        }
    }

    public DailyCrew DailyCrew { get; set; }
    public ContractTask ContractTask { get; set; }

}

我没有将计算返回到ElapsedTime。是因为我将时间存储在字符串中，然后将其解析为TimeSpan吗？我不确定这是怎么回事。

谢谢

瑞安

Answer 1

您正在检查两个值是否都为null，这不会给您任何帮助。您需要改为同时检查两个都不为空/空：

if (!String.IsNullOrEmpty(activity_start) && !String.IsNullOrEmpty(activity_end))
{
    ...
}

使用C＃在MVC模型中计算时间跨度

1 个答案: