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我在 ios 中使用摇晃功能。它与下面的代码工作正常。但是当我进行剧烈摇晃时，它检测到了摇晃，并在一秒钟内调用了这条线if (histeresisExcited && !L0AccelerationIsShaking(self.lastAcceleration, acceleration, 0.2)) { histeresisExcited = NO;}，尽管我一直在摇晃。

如何实现剧烈摇晃？

我在这里做错了什么？

// Ensures the shake is strong enough on at least two axes before declaring it a shake.
// "Strong enough" means "greater than a client-supplied threshold" in G's.
static BOOL L0AccelerationIsShaking(UIAcceleration* last, UIAcceleration* current, double threshold) {
    double
            deltaX = fabs(last.x - current.x),
            deltaY = fabs(last.y - current.y),
            deltaZ = fabs(last.z - current.z);

    return
            (deltaX > threshold && deltaY > threshold) ||
            (deltaX > threshold && deltaZ > threshold) ||
            (deltaY > threshold && deltaZ > threshold);
}

@interface L0AppDelegate : NSObject <UIApplicationDelegate> {
    BOOL histeresisExcited;
    UIAcceleration* lastAcceleration;
}

@property(retain) UIAcceleration* lastAcceleration;

@end

执行

@implementation L0AppDelegate

- (void)applicationDidFinishLaunching:(UIApplication *)application {
     [UIAccelerometer sharedAccelerometer].delegate = self;
}

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

    if (self.lastAcceleration) {
            if (!histeresisExcited && L0AccelerationIsShaking(self.lastAcceleration, acceleration, 0.7)) {
                    histeresisExcited = YES;

                    /* SHAKE DETECTED. DOING SOME DATABASE OPERATIONS HERE. */

            } else if (histeresisExcited && !L0AccelerationIsShaking(self.lastAcceleration, acceleration, 0.2)) {
                    histeresisExcited = NO;

                 /* SHAKE STOPPED. CALLING A VIEW CONTROLLER TO DISPLAY THE CONTENTS GOT FROM THE DATABASE*/
            }
    }

    self.lastAcceleration = acceleration;
 }

// and proper @synthesize and -dealloc boilerplate code

 @end

谢谢你的帮助。

4

1 回答 1

1

终于通过我的代码的一点点改变得到了答案

更改以下代码 

static BOOL L0AccelerationIsShaking(UIAcceleration* last, UIAcceleration* current, double threshold) {
double
        deltaX = fabs(last.x - current.x),
        deltaY = fabs(last.y - current.y),
        deltaZ = fabs(last.z - current.z);

return
        (deltaX > threshold && deltaY > threshold) ||
        (deltaX > threshold && deltaZ > threshold) ||
        (deltaY > threshold && deltaZ > threshold);

}

到

static BOOL L0AccelerationIsShaking(UIAcceleration* last, UIAcceleration* current, double threshold) {
double
        deltaX = fabs(last.x - current.x),
        deltaY = fabs(last.y - current.y),
        deltaZ = fabs(last.z - current.z);

return
        (deltaX > threshold) ||
        (deltaY > threshold) ||
        (deltaZ > threshold);

}

像魅力一样工作。

希望它对像我这样的人有所帮助。

于 2012-09-05T08:44:11.553 回答