Question

Hello其他程序员。我目前正在尝试开发锻炼计时器。在用户按下“开始”按钮之前，他/她使用步进器设置秒数和分钟数。

让我们想象一下，我将锻炼的总长度设定为5分30秒。不幸的是，计时器从30秒开始。实际上，我试图让它从5:30开始。我正在尝试修复方法中的某些内容。这是头文件的代码：

#import <UIKit/UIKit.h>

@interface AutoLayoutViewController : UIViewController
// 1. The three green labels
// Workout's timer
{
    IBOutlet UILabel *workoutTimer;
    NSTimer *workoutCountdown;
    int remainingTime;
}


// 2. The stepper

// Stepper for Workout's total length
@property (strong, nonatomic) IBOutlet UIStepper *secondsWorkoutChanged;


// 4. The button
@property (strong, nonatomic) IBOutlet UIButton *resetButton;

其次，这是实现文件的代码：

#import "AutoLayoutViewController.h"

@interface AutoLayoutViewController ()

@end

// Variables associated with label called Workout's total length
int seconds;
int minutes;

@implementation AutoLayoutViewController

// 1. Steppers

// Stepper for Workout's length
- (IBAction)secondsWorkoutChanged:(UIStepper *)sender {

    /* User increases value of seconds with stepper. Whenever variable for seconds is equal or greater than 60, the program sets the value of minutes through this division: seconds / 60. */
    seconds = [sender value];
    int minutes = seconds / 60;


    /* "If" statement for resetting seconds to 0 in order for the label to look like a watch. REAL number of seconds stored by stepper modulus operated by 60.
     */
    if (seconds > 59) {
        seconds = seconds % 60;
    }

    [workoutTimer setText: [NSString stringWithFormat:@"%2i : %2i", (int) minutes, (int) seconds]];

}




// 2. The button

// Method for countdown

- (void)chrono:(NSTimer *)timer
{

    seconds = seconds -= 1;

    workoutTimer.text = [NSString stringWithFormat: @"%2i : %2i", minutes, seconds];

   if (seconds <= 0) {
        [workoutCountdown invalidate];
    }
}

 //Start button
-(IBAction) startPauseButton:(UIButton *)sender {

    workoutCountdown = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(chrono:) userInfo:nil repeats:YES];
}


- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

总而言之，我一直在尝试编写“开始”按钮和计时方法，以便倒计时注意用户设置的实际分钟数和秒数。然而，到目前为止一直无济于事。我想对任何帮助我的人表示感谢。

Answer 1

minutes变量重置为0的原因是，它已在方法中重新初始化：

- (IBAction)secondsWorkoutChanged:(UIStepper *)sender {

      seconds = [sender value];
      int minutes = seconds / 60;

替换行：

int minutes = seconds / 60;

行：

minutes = seconds / 60;

此外，这是一个我建议实施minutes倒计时的逻辑：

- (void)chrono:(NSTimer *)timer
{
     seconds = seconds -= 1;
     workoutTimer.text = [NSString stringWithFormat: @"%2i : %2i", minutes, seconds];

     if (seconds <= 0) {
         if (minutes <= 0) {
             [workoutCountdown invalidate];
         }
         else {
             seconds = 60;
             minutes -= 1;
         }
     }
}

希望这有帮助！

Objective-C：使用NSTimer倒计时

1 个答案: