我在这样指定的表单上有一个DateTimePicker控件:
dtpEntry.Format = DateTimePickerFormat.Custom;
dtpEntry.CustomFormat = "dd/MM/yyyy hh:mm:ss";
dtpEntry.ShowUpDown = true;
我希望用户只能以 5 分钟的增量增加或减少时间。
关于如何实现这一目标的任何建议?
我在这样指定的表单上有一个DateTimePicker控件:
dtpEntry.Format = DateTimePickerFormat.Custom;
dtpEntry.CustomFormat = "dd/MM/yyyy hh:mm:ss";
dtpEntry.ShowUpDown = true;
我希望用户只能以 5 分钟的增量增加或减少时间。
关于如何实现这一目标的任何建议?
通过观察 ValueChanged 事件并覆盖该值是可能的。此示例表单效果很好:
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
dateTimePicker1.CustomFormat = "dd/MM/yyyy hh:mm";
dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.ShowUpDown = true;
dateTimePicker1.Value = DateTime.Now.Date.AddHours(DateTime.Now.Hour);
mPrevDate = dateTimePicker1.Value;
dateTimePicker1.ValueChanged += new EventHandler(dateTimePicker1_ValueChanged);
}
private DateTime mPrevDate;
private bool mBusy;
private void dateTimePicker1_ValueChanged(object sender, EventArgs e) {
if (!mBusy) {
mBusy = true;
DateTime dt = dateTimePicker1.Value;
if ((dt.Minute * 60 + dt.Second) % 300 != 0) {
TimeSpan diff = dt - mPrevDate;
if (diff.Ticks < 0) dateTimePicker1.Value = mPrevDate.AddMinutes(-5);
else dateTimePicker1.Value = mPrevDate.AddMinutes(5);
}
mBusy = false;
}
mPrevDate = dateTimePicker1.Value;
}
}
我对 SixOThree 的答案稍作改动,以消除 Necromporph 发现的错误。应该可以这样:
在课堂里
private DateTime prevTimePicker1;
private bool navigatingDateTimePicker = false;
在构造函数中
prevTimePicker1 = dateTimePickerStart.Value;
navigatingDateTimePicker = false;
事件
private void dateTimePickerStart_ValueChanged(object sender, EventArgs e)
{
if (!navigatingDateTimePicker) {
/* First set the navigating flag to true so this method doesn't get called again while updating */
navigatingDateTimePicker = true;
/* using timespan because that's the only way I know how to round times well */
TimeSpan tempTS = dateTimePickerStart.Value - dateTimePickerStart.Value.Date;
TimeSpan roundedTimeSpan;
TimeSpan TDBug = dateTimePickerStart.Value - prevTimePicker1;
if (TDBug.TotalMinutes == 59)
{
// first: if we are going back and skipping an hour it needs an adjustment
roundedTimeSpan = TimeSpan.FromMinutes(5 * Math.Floor((tempTS.TotalMinutes - 60) / 5));
dateTimePickerStart.Value = dateTimePickerStart.Value.Date + roundedTimeSpan;
}
else if (dateTimePickerStart.Value > prevTimePicker1)
{
// round up to the nearest interval
roundedTimeSpan = TimeSpan.FromMinutes(5 * Math.Ceiling(tempTS.TotalMinutes / 5));
dateTimePickerStart.Value = dateTimePickerStart.Value.Date + roundedTimeSpan;
} else {
// round down to the nearest interval from prev
roundedTimeSpan = TimeSpan.FromMinutes(5 * Math.Floor(tempTS.TotalMinutes / 5));
dateTimePickerStart.Value = dateTimePickerStart.Value.Date + roundedTimeSpan;
}
navigatingDateTimePicker = false;
}
prevTimePicker1 = dateTimePickerStart.Value;
}
问题是上/下控件自动增加或减少日期/时间选择器当前突出显示的部分(即年/月/日/小时/等)。
您最好在日期/时间选择器附近添加自己的上/下控件(可能是一个非常小的 vscrollbar),并将其连接到从日期/时间选择器的值开始递增/递减五分钟间隔。
或者干脆试试这个:
private void dateTimePicker1_ValueChanged(object sender, EventArgs e)
{
if (this.dateTimePicker1.Value.Minute % 5 == 0)
return;
if (this.dateTimePicker1.Value.Minute % 5 == 1)
this.dateTimePicker1.Value = this.dateTimePicker1.Value.AddMinutes(4);
if (this.dateTimePicker1.Value.Minute % 5 == 4)
this.dateTimePicker1.Value = this.dateTimePicker1.Value.AddMinutes(-4);
}
我知道这是一篇旧文章,但我根据上面的答案为这个问题创建了一个更好的解决方案。
在课堂里
private DateTime prevTimePicker1;
private bool navigatingDateTimePicker = false;
在构造函数中
prevTimePicker1 = dateTimePickerStart.Value;
navigatingDateTimePicker = false;
事件
private void dateTimePickerStart_ValueChanged(object sender, EventArgs e)
{
if (!navigatingDateTimePicker) {
/* First set the navigating flag to true so this method doesn't get called again while updating */
navigatingDateTimePicker = true;
/* using timespan because that's the only way I know how to round times well */
TimeSpan tempTS = dateTimePickerStart.Value - dateTimePickerStart.Value.Date;
TimeSpan roundedTimeSpan;
if (dateTimePickerStart.Value > prevTimePicker1) {
// round up to the nearest interval
roundedTimeSpan = TimeSpan.FromMinutes(5 * Math.Ceiling(tempTS.TotalMinutes / 5));
dateTimePickerStart.Value = dateTimePickerStart.Value.Date + roundedTimeSpan;
} else {
// round down to the nearest interval from prev
roundedTimeSpan = TimeSpan.FromMinutes(5 * Math.Floor(tempTS.TotalMinutes / 5));
dateTimePickerStart.Value = dateTimePickerStart.Value.Date + roundedTimeSpan;
}
navigatingDateTimePicker = false;
}
prevTimePicker1 = dateTimePickerStart.Value;
}
您可以添加此代码
int minuteDiff = dtpJamAppointmentDokter.Value.Minute - prevTimePicker1.Minute;
if (minuteDiff == 59)
{
dtpJamAppointmentDokter.Value = dtpJamAppointmentDokter.Value.AddHours(-1);
}
前
TimeSpan tempTS = dtpJamAppointmentDokter.Value - dtpJamAppointmentDokter.Value.Date;