Question

我有一个简单的秒表，可以在几秒钟内按下开始按钮后的经过时间。我需要的是从日期选择器设置开始时间。

如何获得“NSTimeInterval时间”;等于我的datepicker？或者我是否需要做其他事情来设置用户的时间？

@implementation ViewController {

bool start;

// Gets time when the button is pressed.
NSTimeInterval time;

}

（无效）viewDidLoad中 { [super viewDidLoad];

self.display.text = @“0:00”;

start = false;

}

- （void）更新{

if (start == false) {

    return;

}

NSTimeInterval currentTime = [NSDate timeIntervalSinceReferenceDate];
NSTimeInterval elapsedTime = currentTime - time;

//  minutes.
int minutes = (int)(elapsedTime / 60.0);

// seconds.
int seconds = (int)(elapsedTime = elapsedTime - (minutes * 60));


self.display.text = [NSString stringWithFormat:@"%u:%02u", minutes, seconds];

[self performSelector:@selector(update) withObject:self afterDelay:0.1];

}

Answer 1

您可以使用：

NSTimeInterval timePicker = [[self.datePicker date] timeIntervalSinceReferenceDate];
NSTimeInterval currentTime = [[NSDate date] timeIntervalSinceReferenceDate];
NSTimeInterval elapsedTime = currentTime - timePicker;
//  minutes.
   int minutes = (int)(elapsedTime / 60.0);

// seconds.
   int seconds = (int)(elapsedTime = elapsedTime - (minutes * 60));

Answer 2

只需保存开始NSDate. Later get the current NSDate and use timeIntervalSinceDate：or timeIntervalSinceNow`即可获取已用时间。

保存开始时间：

NSTimeInterval startTime = [NSDate date];

随后：

NSTimeInterval elapsedTime = -[[NSDate date] timeIntervalSinceNow];

秒表 - 从UIDatePicker设置开始日期

2 个答案: