IOS implementation Shake source code __ios

. h Files

@interface shakeviewcontroller:uiviewcontroller<uiaccelerometerdelegate>
{
    uiaccelerationvalue    myaccelerometer[3];

    Whether to respond to a shake of the flag
    BOOL  _canshake;
    

In the. m file

#define KFILTERINGFACTOR 0.1 #define KERASEACCELERATIONTHRESHOLD 2.0 @implementation Shakeviewcontr Oller-(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 >= Keraseaccelerationthre
        Shold) {//whether response to shake the sign _canshake = NO;
    [Self shakeevent]; }
}