CMMotionManager是全局资源吗?这是什么意思? [英] CMMotionManager is a global resource? What does this means?
问题描述
我正在尝试初始化CMMotionManager，因此开始更新并创建参考姿态矩阵，然后当我单击情节提要中的按钮时，我显示另一个屏幕(位于视图控制器中)，并且我想使用参考姿态矩阵和运动管理器提供的其他读数，但是如果我进行简单的检查以查看其是否准备就绪，则表示它尚未准备就绪(甚至认为它在先前的屏幕上已准备就绪).
I am trying to initialize the CMMotionManager so start updates and create a reference attitude matrix, and then when i click a button trough the storyboard, i display a different screen (which is in a viewcontroller) and i want to use the reference attitude matrix and other readings from the motion manager but if I do a simple check to see if its ready it says it isnt (even thought it was ready on the previous screen).
所以我在进行一些研究，发现一些斯坦福大学的笔记说这是一种全球资源，因此可以使用委托或类，这让我很想念.
So I was researching a little bit and i came across some standford notes that say it is a global resource so that it is ok to either use delegates or classes, that got me thinking.
如果我使用委托，那么从技术上讲，资源的所有者正在为我执行操作，对吗?所以这并不真的意味着它是全球性的.
If i use a delegate then technically the owner of the resource is doing the action for me right? so it doesnt really mean it is global.
那类呢?我尝试实现MotionManager类，但是我仍然没有在第二个屏幕上得到任何读数...而且我只是没有在新屏幕上再次初始化它，因为我不想同时运行多个实例.
What about classes? i tried implementing a MotionManager Class but i still didnt get any readings on the second screen... and i just didnt initialize it again on the new screen because i dont want to have multiple instances runing at the same time.
要解决我的问题，我还想我可以在主要对象中将其初始化一次，保存姿态，在segue过渡中将其传递给下一个对象，然后重新初始化运动管理器，这样我只有1个实例(或关闭屏幕上的旧内容将消失).
To solve my problem i also suppose i could initialize it once in the main one, save the attitude, pass it to the next one in a segue transition and just re initialize the motion manager so i only have 1 instance (or close old one on screen will dissapear).
但是我不希望这样，因为用户可能会立即在屏幕上单击，而运动管理器确实会花一点时间进行初始化(或者就是我注意到的那样).
But i do not want this because the user might click right away on the screen and the motion manager does take a little bit of time to initialize (or thats what i noticed).
在此先感谢您提供的任何帮助.
Thanks in advance for any help you can provide.
好吧，我尝试了委托方法，但仍然无法从第二个窗口中的设备管理器中读取内容.我想到的是，当我转到第二个窗口xcode时，也许会自动释放我的Motion管理器实例...(CMMotionManager).
Ok i tried the delegate method and i still cant read from the device manager in the second window. What comes to mind is that MAYBE when I am going to the second window xcode is automaticaly releasing my instance of Motion manager.... (CMMotionManager).
有人知道如何检查吗?
推荐答案
我希望我理解正确.然后，我建议使用单例设计模式将运动管理器访问封装在一个专门的类中.一些伪代码:
I hope I understood you right. Then I suggest using a singleton design pattern encapsulating motion manager access in a specialised class. Some pseudo code:
MotionHandler.h
MotionHandler.h
@interface MotionHandler {
CMMotionManager* motionManager;
+ (MotionHandler*) getInstance;
}
MotionHandler.c:
MotionHandler.c:
@interface MotionHandler {
static MotionHandler* instance;
+ (MotionHandler*) getInstance {
if (instance == nil) {
instance = [[self alloc] init];
}
return instance;
}
- (id)init {
if ((self = [super init])) {
motionManager = [[CMMotionManager alloc] init];
// initialise CMMotionManager
}
}
}
因此，只有一个MotionHandler实例可以管理对CMMotionManager的访问.您可以使用 MotionHandler.getInstance.motionManager 从任何地方访问CMMotionManager实例.
So there is one instance of MotionHandler only which manages access to CMMotionManager. You can accesss your CMMotionManager instance from everywhere with MotionHandler.getInstance.motionManager.
如果您需要从多个类访问CoreMotion，建议您完全封装CMMotionManager访问权限.这意味着将其设为@private并提供诸如getDeviceMotion，setReferenceAttitude等方法.这有助于避免诸如两次启动或在启动之前访问CMDeviceMotion之类的麻烦，并使调试更加方便.
If you need access to CoreMotion from several classes, I recommend total encapsulation of CMMotionManager access. That means make it @private and provide methods like getDeviceMotion, setReferenceAttitude, ... This helps to avoid complications like starting it twice or access to CMDeviceMotion before start and makes it more convenient to debug.
这篇关于CMMotionManager是全局资源吗?这是什么意思?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
