加速度计android倾斜功能

Question

Im testing out the accelerometer, and trying to make a program that show a text depending on where the user tilts the phone. I have a text that will show when the user tilts the phone right/left and up/down.

I am new to android so if you think this question is stupid, please dont vote down! Tell my what i did wrong with the question so i can do beter next time!

The code below dosent work well, i only get right and top.. and i cant figure out why..

The code for doing this:

@Override
    public void onSensorChanged(SensorEvent event) {
        // get the change of the x,y,z values of the accelerometer
        deltaX = Math.abs(lastX - event.values[0]);
        deltaY = Math.abs(lastY - event.values[1]);
        deltaZ = Math.abs(lastZ - event.values[2]);

        if (deltaX > 2){
            HideText();
            findViewById(R.id.txtRight).setVisibility(View.VISIBLE);
        }
        if (deltaY > 2)
        {
            HideText();
            findViewById(R.id.txtUp).setVisibility(View.VISIBLE);
        }
        if (deltaX < -2)
        {
            HideText();
            findViewById(R.id.txtLeft).setVisibility(View.VISIBLE);
        }
        if (deltaY < -2) {
            HideText();
            findViewById(R.id.txtUp).setVisibility(View.VISIBLE);
        }

        /*else if ((deltaX > vibrateThreshold) || (deltaY > vibrateThreshold) || (deltaZ > vibrateThreshold)){
            v.vibrate(100);
            HideText();
            Toast.makeText(getApplicationContext(), "Stop shaking me!!!",
                    Toast.LENGTH_LONG).show();
        }*/


    }

The code that is comment out i tried to use if the user shakes the phone.. but will save that for later :)

Answer 1

The code looks fine. Your problem comes from Math.abs() - it takes the absolute value of the difference which means it always makes it positive and deltaX and deltaY will never be <0. Remove Math.abs() and it should be OK.