Ios oc multi-task timer nsunloop management NSTimer

The following two methods are available:

1. Use the date component NSDateComponents

2. Use NSString to generate a date

// Create a Calendar Object

NSCalendar * calendar = [NSCalendarcurrentCalendar];

// Create date component

NSDateComponents * dc = [[NSDateComponentsalloc] init];

// Set the current time

[Dc setCalendar: calendar];

[Dc setYear: 2014];

[Dc setMonth: 4];

[Dc setDay: 9];

[Dc setHour: 21];

[Dc setMinute: 26];

[Dc setSecond: 0];

NSString * dateStr = @ "2014-04-0921: 38: 00 ";

NSDateFormatter * formatter = [[NSDateFormatteralloc] init];

Formatter. dateFormat = @ "yyyy-MM-ddHH: mm: ss ";

NSDate * schuduleNate = [dcdate];

NSDate * schuduleNate2 = [formatterdateFromString: dateStr];

NSDate * dateNow = [NSDatedate];

// Calculate the time difference

NSTimeInterval num = [schuduleNate2timeIntervalSinceDate: dateNow];

NSLog (@ "% f and then start executing the task", num );

// Task pool

Nsunloop * mainLoop = [nsunloopcurrentrunloop];

//

NSTimer * timer = [NSTimerscheduledTimerWithTimeInterval: num target: self selector: @ selector (scheduleTask) userInfo: nil repeats: NO];

NSTimer * timer2 = [NSTimerscheduledTimerWithTimeInterval: num + 3 target: self selector: @ selector (scheduleTask) userInfo: nil repeats: NO];

// Add to task pool

[MainLoop addTimer: timer forMode: NSDefaultRunLoopMode];

[MainLoop addTimer: timer2 forMode: NSDefaultRunLoopMode];

[MainLoop run];

Output Information

21:37:54. 289 WeChat [1810: 60b] 5.710526

21:38:00. 001 WeChat [1810: 60b] do some thing

21:38:03. 001 WeChat [1810: 60b] do some thing