winform 时间控件 可以选择时分 设置为空

DateTimePicker.ShowUpDown = true;
DateTimePicker.CustomFormat = "hh:mm";
DateTimePicker.Format = System.Windows.Forms.DateTimePickerFormat.Custom;

设置为空

dtp.Format = DateTimePickerFormat.Custom;
dtp.CustomFormat = " ";
dtp.Value = DateTime.FromOADate(0);
dtp.Text = string.Empty;