How to use NSTimeInterval

By using NSTimeInterval, we can easily handle operations such as time intervals, calculating time differences, creating timers, and delaying task execution.

NSTimeInterval is a data type in Objective-C used to represent time intervals. It is a double precision floating point number in seconds. In iOS development, we often need to use NSTimeInterval to calculate time differences, timers and other operations. This article will introduce how to use NSTimeInterval to implement some common functions.

1. Get the current timestamp

In iOS development, we often need to get the current timestamp. You can use the timeIntervalSince1970 method of the NSDate class to get the number of seconds since January 1, 1970. The sample code is as follows:

NSTimeInterval currentTimeInterval = [[NSDate date] 
timeIntervalSince1970];

2. Calculate the time difference

Sometimes we need to calculate the difference between two times, which can be achieved using NSTimeInterval. First, we need to get the timestamps of two times and then subtract them. The sample code is as follows:

NSDate *startDate = [NSDate date];
// do something...
NSDate *endDate = [NSDate date];
NSTimeInterval timeInterval = [endDate timeIntervalSinceDate:startDate];

3. Timer

In iOS development, we often need to use timers to perform some periodic tasks. You can use the NSTimer class to create a timer and specify the timer trigger interval. The time interval parameter of NSTimer needs to use the NSTimeInterval type. The sample code is as follows:

NSTimeInterval timeInterval = 1.0; // 1秒钟
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:timeInterval 
target:self selector:@selector(timerFired:) userInfo:nil repeats:YES];
// 定时器触发时执行的方法
- (void)timerFired:(NSTimer *)timer {
NSLog(@"Timer fired!");
}

4. Delayed execution

Sometimes we need to execute a task after a period of time, and we can use NSTimeInterval to achieve delayed execution. You can use the performSelector:withObject:afterDelay: method of the NSObject class to implement delayed execution. The sample code is as follows:

NSTimeInterval delay = 2.0; // 2秒钟
[self performSelector:@selector(delayedTask) withObject:nil 
afterDelay:delay];
// 延迟执行的任务
- (void)delayedTask {
NSLog(@"Delayed task executed!");
}

The above are some common uses of NSTimeInterval. By using NSTimeInterval, we can easily handle operations such as time intervals, calculating time differences, creating timers, and delaying task execution. In actual development, according to specific needs, we can flexibly use NSTimeInterval to implement various time-related functions. .

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