iOS一些常用的小知识点

//获取全局的Delegate对象，这样我们可以调用这个对象里的方法和变量

[[UIApplication sharedApplication] delegate];

//获得程序的主Bundle

NSBundle *bundle = [NSBundle mainBundle];

/*

在程序中播放声音

1.添加AudioToolbox框架

*/

NSString *path = [bundle pathForResource:@"soundFileName" ofType:@"wav"];

SystemSoundID soundId;

AudioServicesCreateSystemSoundID((__bridge CFURLRef)([NSURL URLWithString:path]), &soundId);

AudioServicesPlayAlertSound(soundId);

//捕捉程序关闭或者进入后台事件

UIApplication *application = [UIApplication sharedApplication];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:application];

}

- (void)applicationWillResignActive:(NSNotification *)noti{

}

#pragma mark -- 获取截屏

- (UIImage *)getScreenShot{

UIGraphicsBeginImageContext(self.view.bounds.size);

[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}