Question

我想用开关（来自菜单类）启动/停止计时器（在主类中），根据我的代码，当开关打开时定时器启动，当我关闭开关时定时器不停止。这是我的代码：

menu.h

@protocol FlipsideViewControllerDelegate;
@interface FlipsideViewController : UIViewController  {
id <FlipsideViewControllerDelegate> delegate;
IBOutlet UISwitch *fireSwitch;
}
@property (assign)UISwitch* fireSwitch;
-(IBAction)autoFire;

menu.m

#import "FlipsideViewController.h"
#import "mainViewController.h"
@synthesize fireSwitch;

- (void)viewDidLoad
{
   NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
//[super viewDidLoad];
fireSwitch.on = [defs boolForKey:activateautoplay];

}

-(IBAction)autoFire {
          NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
[defs setBool:fireSwitch.on forKey:activateautoplay];
[[NSUserDefaults standardUserDefaults] synchronize];
}

Main.h

#import "FlipsideViewController.h"
#define activateautoplay @"isactivateautoplay"
@interface mainViewController : UIViewController <FlipsideViewControllerDelegate> {
NSTimer *Autotimer;
}
-(void)updateImagePosition:(NSTimer*)mytimer;

的main.m

#import "mainViewController.h"
@sunthesize Autotimer;

- (void)awakeFromNib {
NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
if ([defs boolForKey:activateautoplay]) {
    self.Autotimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(updateImagePosition:) userInfo:nil repeats:YES];
} else {
    [self.Autotimer invalidate];
}
}


-(void)updateImagePosition:(NSTimer*)mytimer {
.....
}

Answer 1

如果您不介意在两个类之间引入耦合，您可以随时向FlipsideViewController提供对mainViewController的引用，并让它直接引用方法。或者，您可以让FlipsideViewController在更改值时向其委托发送相应的消息，然后可以调用mainViewController。

但从避免不必要耦合的角度来看，最好的方法是让mainViewController监听NSUserDefaultsDidChangeNotification，这会在调用setBool:forKey:时自动发送。

请求编辑：

在Main.m中，添加如下方法：

- (void)startOrStopTimer {
    NSUserDefaults *defs = [NSUserDefaults standardUserDefaults];
    if ([defs boolForKey:activateautoplay]) {
        if (!self.Autotimer) self.Autotimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(updateImagePosition:) userInfo:nil repeats:YES];
    } else {
        [self.Autotimer invalidate];
        self.Autotimer = nil;
    }
}

然后将awakeFromNib更改为以下内容：

- (void)awakeFromNib {
    [self startOrStopTimer];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(startOrStopTimer) name:NSUserDefaultsDidChangeNotification object:nil];
}

请务必将其添加到dealloc：

    [[NSNotificationCenter defaultCenter] removeObserver:self];

FlipsideViewController不需要进行任何更改，也不需要设置包。

iPhone UISwitch启动/停止NSTimer帮助！

1 个答案: