Question

有没有办法我可以将DateTimePicker默认为下周五，所以它应该总是默认为星期五，它将在下周出现。即使他们选择了本周的周五。我有以下代码作为我的尝试：但是在修改时 if (selectedDate.DayOfWeek != DayOfWeek.Friday)至：
if (selectedDate.DayOfWeek == DayOfWeek.Friday)它循环播放。如下所示将其设置为星期五然后点击更改的事件并显示为星期五，因此(selectedDate.DayOfWeek == DayOfWeek.Friday)代码也会导致无限循环。

var dtp = pSender as DateTimePicker;
var selectedDate = dtp.Value;

if (selectedDate.DayOfWeek != DayOfWeek.Friday)
{
   var offset = (int)DayOfWeek.Friday - (int)selectedDate.DayOfWeek + 7;  //Friday after current week.
   var friday = selectedDate + TimeSpan.FromDays(offset);

   dtp.Value = friday;
}

感谢您的时间，

Answer 1

如果您处理DateTimePicker.ValueChanged事件并在那里更改值，那么它是一个无限循环。您应该只在Form，Form_Load事件的构造函数中执行此操作，或者您必须检查它是否以编程方式完成：

private bool dtpChangedManually = false;
protected void Dtp_ValueChanged(Object sender, EventArgs e)
{
    if (dtpChangedManually)
    {
        dtpChangedManually = false;
        return;
    }

    dtpChangedManually = true;

    var pSender = (DateTimePicker) sender;
    int daysUntilFridDay = ((int)DayOfWeek.Friday - (int)pSender.Value.DayOfWeek + 7) % 7;
    if(daysUntilFridDay == 0) daysUntilFridDay = 7;
    DateTime nextFriday = pSender.Value.AddDays(daysUntilFridDay);
    pSender.Value = nextFriday;
}

DateTimePicker默认为下周的星期五

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