Instance 365 (6) --------- DateTime. ToString format date, use the DateDiff method to obtain the number of Date and Time Intervals

I. DateTime. ToString format date,

Ii. Code

Using System; using System. collections. generic; using System. componentModel; using System. data; using System. drawing; using System. linq; using System. text; using System. windows. forms; namespace TmrFormat {public partial class Frm_Main: Form {public Frm_Main () {InitializeComponent ();} /* parameter format detailed usage format character Association attributes/description d ShortDatePattern D LongDatePattern f complete date and time (long date and short time) F FullDateTimePattern (long date and long time) g regular (short date and short time) G regular (short date and long time) m, M MonthDayPattern r, R RFC1123Pattern s use local time SortableDateTimePattern (based on ISO 8601) t ShortTimePattern T LongTimePattern u UniversalSortableDateTimePattern is used to display the format of Universal Time U use the complete date and time of Universal Time (long date and long time) y, Y YearMonthPattern */private void btn_GetTime_Click (object sender, EventArgs e) {lab_time.Text = DateTime. now. toString ("d") + "\ n" + // format the DateTime string using the string variable in the specified format. now. toString ("D") + "\ n" + DateTime. now. toString ("f") + "\ n" + DateTime. now. toString ("F") + "\ n" + DateTime. now. toString ("g") + "\ n" + DateTime. now. toString ("G") + "\ n" + DateTime. now. toString ("R") + "\ n" + DateTime. now. toString ("y") + "\ n" + "current system time:" + DateTime. now. toString (// format the string in the custom format "yyyy MM dd HH mm ss seconds ");}}}

3. Use the DateDiff method to obtain the date and time intervals,

4. Code

Using System; using System. windows. forms; using Microsoft. visualBasic; namespace GetDateDiff {public partial class Frm_Main: Form {public Frm_Main () {InitializeComponent ();}/* Parameter Interval Type: Microsoft. visualBasic. dateInterval is required. The DateInterval enumerated value or String expression indicates the time interval between the units to be used as the difference between Date1 and Date2. Date1 type: required by System. DateTime. Date. The first Date/time value to be used in the calculation. Date2 type: required by System. DateTime. Date. The second Date/time value to be used in the calculation. DayOfWeek type: Microsoft. VisualBasic. FirstDayOfWeek is optional. The value selected from the FirstDayOfWeek enumeration to specify the first day of a week. If not specified, use FirstDayOfWeek. Sunday. WeekOfYear type: Microsoft. VisualBasic. FirstWeekOfYear is optional. The value selected from the FirstWeekOfYear enumeration to specify the first week of the year. If not specified, use FirstWeekOfYear. Jan1. Return Value Type: System. Int64 returns a Long value, which specifies the time interval between two Date values. */Private void btn_Get_Click (object sender, EventArgs e) {MessageBox. show ("interval" + DateAndTime. dateDiff (// use the DateDiff method to obtain the date interval DateInterval. day, dtpicker_first.Value, dtpicker_second.Value, FirstDayOfWeek. sunday, FirstWeekOfYear. jan1 ). toString () + "day", "interval ");}}}