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Android_方向傳感器

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Android方向傳感器小案例,主要代碼如下:

package com.hb.direction;

import android.app.Activity;
import android.content.Context;
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 { private SensorManager sm; private ImageView iv_compress; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); iv_compress
=(ImageView) findViewById(R.id.iv_compass); sm = (SensorManager) getSystemService(Context.SENSOR_SERVICE); //地磁場 Sensor magnetic = sm.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD); //加速度 Sensor acceleromter = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); sm.registerListener(listener, magnetic, SensorManager.SENSOR_DELAY_GAME); sm.registerListener(listener, acceleromter, SensorManager.SENSOR_DELAY_GAME); } @Override
protected void onDestroy() { super.onDestroy(); if( sm!=null){ sm.unregisterListener(listener); } } private SensorEventListener listener=new SensorEventListener() { float[] magneticValues=new float[3]; float[] acceleromterValues=new float[3]; private float lastRotateDegree; @Override public void onSensorChanged(SensorEvent event) { //判斷當前是加速度還是地磁場傳感器 if(event.sensor.getType()==Sensor.TYPE_ACCELEROMETER){ acceleromterValues=event.values.clone(); }else if(event.sensor.getType()==Sensor.TYPE_MAGNETIC_FIELD){ magneticValues=event.values.clone(); } float [] R=new float[9]; float [] values=new float[3]; SensorManager.getRotationMatrix(R, null, acceleromterValues, magneticValues); SensorManager.getOrientation(R, values); //toDegreess轉化為度 // tv_direction.setText("values is"+Math.toDegrees(values[0])); // Toast.makeText(MainActivity.this, "values is"+Math.toDegrees(values[0]), 0).show(); //將計算出的旋轉角取反用於指南針背景圖 float roteteDegree=-(float)Math.toDegrees(values[0]); if((Math.abs(roteteDegree)-lastRotateDegree)>1){ RotateAnimation animation = new RotateAnimation(lastRotateDegree, roteteDegree,Animation.RELATIVE_TO_SELF, 0.5f,Animation.RELATIVE_TO_SELF,0.5f); animation.setFillAfter(true); iv_compress.startAnimation(animation); lastRotateDegree=roteteDegree; } } @Override public void onAccuracyChanged(Sensor sensor, int accuracy) { } }; }

布局文件xml:

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     tools:context="${relativePackage}.${activityClass}" >
 6 
 7     <ImageView
 8         android:id="@+id/iv_arrow"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:layout_centerInParent="true"
12         android:src="@drawable/arrow3" />
13 
14     <ImageView
15         android:id="@+id/iv_compass"
16         android:layout_width="wrap_content"
17         android:layout_height="wrap_content"
18         android:layout_centerInParent="true"
19         android:src="@drawable/compass" />
20 
21 </RelativeLayout>

源碼下載地址:http://pan.baidu.com/s/1i4HIMSP

Android_方向傳感器