【实例简介】

【实例截图】

【核心代码】

package cn.icast.zhinanzhen;

import android.app.Activity;

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.hardware.Sensor;

import android.hardware.SensorEvent;

import android.hardware.SensorEventListener;

import android.hardware.SensorManager;

import android.os.Bundle;

import android.view.animation.Animation;

import android.view.animation.RotateAnimation;

import android.widget.ImageView;

public class MainActivity extends Activity {

/**获取传感器管理类*/

private SensorManager sensorManager;

/**最新方向值*/

private float degrees;

/**上一次方向值*/

private float lastdegress;

SensorEventListener sensorEventListener = new SensorEventListener() {

/**加速度传感器获取的值*/

float[] acceleValues = new float[3];

/**地磁传感器获取的值*/

float[] magneticValues = new float[3];

@Override

public void onSensorChanged(SensorEvent event) {

//判断当前传感器是否是加速度传感器

if(event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){

//赋值时需要调用clone()方法

acceleValues = event.values.clone();

}else if(event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD){

magneticValues = event.values.clone();

}

float[] values = new float[3];

float[] R = new float[9];

SensorManager.getRotationMatrix(R, null, acceleValues, magneticValues);

SensorManager.getOrientation(R, values);

degrees = -(float)Math.toDegrees(values[0]);

updateImgv();

}

@Override

public void onAccuracyChanged(Sensor sensor, int accuracy) {

}

};

/**指南针出示图片*/

private Bitmap bitmap;

/**指南针图片*/

private ImageView mCompassImgv;

/**临摹一张与指南针图片设置一模一样的空白图片*/

private Bitmap createBitmap;

/**地磁传感器*/

private Sensor masensor;

/**加速度传感器*/

private Sensor accesensor;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);

masensor = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);

accesensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

//注册方向传感器

sensorManager.registerListener(sensorEventListener, masensor, SensorManager.SENSOR_DELAY_GAME);

sensorManager.registerListener(sensorEventListener, accesensor,SensorManager.SENSOR_DELAY_GAME);

initView();

}

/**初始化控件*/

private void initView() {

bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.compass);

mCompassImgv = (ImageView) findViewById(R.id.imgv_compass);

mCompassImgv.setImageBitmap(bitmap);

}

/**更新图片位置*/

private void updateImgv(){

RotateAnimation animation = new RotateAnimation(lastdegress, degrees,Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);

animation.setDuration(200);

animation.setFillAfter(true);

mCompassImgv.startAnimation(animation);

lastdegress = degrees;

}

@Override

protected void onDestroy() {

super.onDestroy();

sensorManager.unregisterListener(sensorEventListener);

}

}