Set an NSTtimer to display the current time

Sets an NSTtimer to display the current time,

Define NSTimer usage: Time Interval NSTimeInterval floating point type, event proxy
Delegate and event processing method @ selector ();
+ (NSTimer *) scheduledTimerWithTimeInterval :( NSTimeInterval) ti target :( id) aTarget selector :( SEL) aSelector userInfo :( id) userInfo repeats :( BOOL) yesOrNo; to initialize a time Timer

Nstcoa is a common Timer class in Cocoa. The basic operations are as follows:
The handleTimer method can be customized. You can create a timer as needed, and handleTimer can be executed every 1.0 seconds.

 

First, obtain the Time of the specified city.

NSString * tmpTimeStr;

NSDate * nowdate = [[NSDate alloc] init];

NSDateFormatter * formatter = [[NSDateFormatter alloc] init];

NSTimeZone * timeZone = [NSTimeZone timeZoneWithName: @ "Asia/Shanghai"];

[Formatter setTimeZone: timeZone];

[Formatter setDateFormat: @ "YYYY-MM-dd-HH-mm-ss"];

NSString * timeStr = [formatter stringFromDate: nowdate];

In this way, the time format is NSString, and NSTimer is set as follows:

NSTimeInterval timeinteger = 1.0;

// Timer

Nstmer * timer;

Timer = [NSTimer scheduledTimerWithTimeInterval: timeInterval

Target: self

Selector: @ selector (showNowTime :)

UserInfo: nil

Repeats: YES];

Set the current time for each second. In this way, the use of an NSTimer is realized.