iphone - iOS - 每次应用程序从后台返回时如何设置滑块的默认值？

Question

我的应用中有这个滑块

- (IBAction)slider1:(id)sender
{
    UISlider *slider = (UISlider *)sender;  //declare slider
    NSLog(@"%f",slider.value;
}

每次应用程序从后台返回时，如何设置滑块的默认值？

Answer 1

UIApplicationWillEnterForegroundNotification为通知添加观察者。

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willEnterForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];


- (void)willEnterForeground:(NSNotification *)n {
    self.slider.value = 0.0f;
}