确定新日期是否为默认的新DateTime()

本文关键字：DateTime 默认 日期 新日期 是否 | 更新日期: 2023-09-27 18:01:09

这是我的问题：

DateTime previousDate = new DateTime();
DateTime currentDate = new DateTime();
foreach (ApproverVo approver in approvers)
{
    if (previousDate != null)
    {
        currentDate = (DateTime)approver.ApprovalDate;
        totalTimeSpan += (currentDate - previousDate).TotalDays;
        previousDate = currentDate;
    } else
        previousDate = (DateTime)approver.ApprovalDate;
}

当在开头声明上一个日期时，它包含DateTime((的默认值。我想做的是弄清楚上一个日期是否分配了正确的日期。

请提供建议，谢谢

确定新日期是否为默认的新DateTime()

假设您的批准日期没有等于DateTime.MinValue:的值

DateTime previousDate = DateTime.MinValue;
DateTime currentDate = new DateTime();
foreach (ApproverVo approver in approvers)
{
    if (previousDate != DateTime.MinValue)
    {
        currentDate = (DateTime)approver.ApprovalDate;
        totalTimeSpan += (currentDate - previousDate).TotalDays;
        previousDate = currentDate;
    } else
        previousDate = (DateTime)approver.ApprovalDate;
}

更新

根据@mdmullinax的回答，上面的代码与类似

DateTime previousDate = new DateTime();
DateTime currentDate = new DateTime();
foreach (ApproverVo approver in approvers)
{
    if (previousDate != new DateTime())
    {
        currentDate = (DateTime)approver.ApprovalDate;
        totalTimeSpan += (currentDate - previousDate).TotalDays;
        previousDate = currentDate;
    } else
        previousDate = (DateTime)approver.ApprovalDate;
}

检查之后的previousDate == DateTime.MinValue

DateTime previousDate = new DateTime();

相当于

DateTime previousDate = DateTime.MinValue;

来自MSDN DateTime Structure文档：

DateTime dat1 = new DateTime();
// The following method call displays 1/1/0001 12:00:00 AM.
Console.WriteLine(dat1.ToString(System.Globalization.CultureInfo.InvariantCulture));
// The following method call displays True.
Console.WriteLine(dat1.Equals(DateTime.MinValue));
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