CoreMotion框架

Question

我最近在做指南針，涉及CoreMotion框架，但是我查了很久沒有找到關於如何實現這個框架的指南針效果的信息，希望能夠得到大家的幫助。

Answer 1

• 蘋果Core Motion Framework Reference
• 蘋果Event Handling Guide for iOS: Core Motion
• 蘋果CoreMotionTeaPot從WWDC ’10 Sample Code
• Get Moving with Core Motion - 喬納森Blocksom
• Getting you started with CoreMotion - 路德維希·舒伯特
• 一個類似的問題：make a compass application in iPad

Answer 2

我的 「HelloWorld」 CoreMotion：

1）在.h文件中添加CoreMotion.framework

2）：

#import <CoreMotion/CoreMotion.h> 

3）.m文件：

CMMotionManager *myMotionManager= [[CMMotionManager alloc] init]; 
myMotionManager.deviceMotionUpdateInterval = 1/60; 
[myMotionManager startDeviceMotionUpdatesUsingReferenceFrame:CMAttitudeReferenceFrameXMagneticNorthZVertical toQueue:[NSOperationQueue currentQueue] withHandler:^(CMDeviceMotion *motion, NSError *error) { 
    double x = myMotionManager.deviceMotion.magneticField.field.x; 
    double y = myMotionManager.deviceMotion.magneticField.field.y; 
    double z = myMotionManager.deviceMotion.magneticField.field.z; 
    NSLog(@"Strength of Earth's magnetic field= %8.2f",sqrt(x*x+y*y+z*z)); 
    myLabel.text = [NSString stringWithFormat:@"%8.2f", sqrt(x*x+y*y+z*z)]; 
}];