ios 摇一摇 仿微信

微信的摇一摇是怎么实现的~发现原来 ios本身就支持
在 UIResponder中存在这么一套方法
 
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0);
 
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0);
 
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0);
 
这就是执行摇一摇的方法。那么怎么用这些方法呢？
 
很简单，你只需要让这个Controller本身支持摇动
 
同时让他成为第一相应者：
 
- (void)viewDidLoad
 
{
 
    [superviewDidLoad];
 
// Do any additional setup after loading the view, typically from a nib.
 
    [[UIApplicationsharedApplication] setApplicationSupportsShakeToEdit:YES];
 
    [selfbecomeFirstResponder];
 
}
 
  
 
然后去实现那几个方法就可以了
 
- (void) motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
 
{
 
    //检测到摇动
 
}
 
  
 
- (void) motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
 
{
 
    //摇动取消
 
}
 
  
 
- (void) motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
 
{
 
    //摇动结束
 
    if (event.subtype == UIEventSubtypeMotionShake) {
 
        //something happens
 
    }
 
}

IOS实现摇一摇源代码

@interface ShakeViewController : UIViewController<UIAccelerometerDelegate>  
{  

    UIAccelerationValue    myAccelerometer[3];  
  

    //是否响应摇一摇的标志  
    BOOL  _canShake;  

      
}  

.m文件中

#define kFilteringFactor                0.1  
#define kEraseAccelerationThreshold        2.0  

  
@implementation ShakeViewController  

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil  
{  

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];  
    if (self) {  

        _canShake = YES;  
    }  

    return self;  
}  

  
- (void)dealloc  

{  
    [UIAccelerometer sharedAccelerometer].delegate = nil;  

    [super dealloc];  
}  

  
- (void)viewDidLoad  

{  
    [super viewDidLoad];  

    [UIAccelerometer sharedAccelerometer].delegate = self;  
    [UIAccelerometer sharedAccelerometer].updateInterval = 1.0f/40.0f;  

}  
  

  
#pragma mark - UIAccelerometerDelegate  

- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration  
{  

UIAccelerationValue  length, x, y, z;  
      

    if (!_canShake)  
    {  

        return;  
    }  

      
    //Use a basic high-pass filter to remove the influence of the gravity  

    myAccelerometer[0] = acceleration.x * kFilteringFactor + myAccelerometer[0] * (1.0 - kFilteringFactor);  
    myAccelerometer[1] = acceleration.y * kFilteringFactor + myAccelerometer[1] * (1.0 - kFilteringFactor);  

    myAccelerometer[2] = acceleration.z * kFilteringFactor + myAccelerometer[2] * (1.0 - kFilteringFactor);  
    // Compute values for the three axes of the acceleromater  

    x = acceleration.x - myAccelerometer[0];  
    y = acceleration.y - myAccelerometer[0];  

    z = acceleration.z - myAccelerometer[0];  
      

    //Compute the intensity of the current acceleration  
    length = sqrt(x * x + y * y + z * z);  

    // If above a given threshold, play the erase sounds and erase the drawing view  
    if(length >= kEraseAccelerationThreshold)  

    {  
        //是否响应摇一摇的标志  

        _canShake = NO;  
        [self shakeEvent];  

    }  
}  

1。 在App's Delegate中设定applicationSupportsShakeToEdit属性：

- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions

{

    

    application.applicationSupportsShakeToEdit= YES; //在ios6.0后，这里其实都可以不写了

    

    self.window= [[UIWindowalloc] initWithFrame:[[UIScreenmainScreen] bounds]];

    // Override point for customization after application launch.

    self.viewController= [[ViewControlleralloc] initWithNibName:@"ViewController"bundle:nil];

    self.window.rootViewController= self.viewController;

    [self.windowmakeKeyAndVisible];

    returnYES;

}

2。在你的View控制器中添加/重载canBecomeFirstResponder, viewDidAppear:以及viewWillDisappear:

//这里很重要，因为大部分视图 默认 的  canBecomeFirstResponder 是 NO的

-(BOOL)canBecomeFirstResponder {

    return YES;

}

-(void)viewDidAppear:(BOOL)animated {

    [super viewDidAppear:animated];

    [self becomeFirstResponder];

}

-(void)viewWillDisappear:(BOOL)animated {

    [self resignFirstResponder];

    [super viewWillDisappear:animated];

}

3。在你的view控制器中添加motionEnded：

-(void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent*)event

{

    if(motion == UIEventSubtypeMotionShake)

    {

        // your code

    }

}

---------------------------------------------------------------

IOS 3.0 + 开始支持motion事件，检测设备摇动 

 – motionBegan:withEvent:       摇动开始时执行 

 – motionEnded:withEvent:       摇动结束时执行

 – motionCancelled:withEvent:  摇动被取消时执行