25-方向传感器实现指南针

来源：互联网发布：机器人语音对话软件编辑：程序博客网时间：2024/05/17 04:05

传感器：手机常用传感器有方向传感器、重力传感器、光线传感器等。

上北0度右东90度下南180度左西 270度

MainActivity

Sensor.TYPE_ORIENTATION 方向传感器

Sensor.TYPE_ACCELEROMETER 重力

Sensor.TYPE_LIGHT 光线

Sensor.TYPE_MAGNETIC_FIELD 磁场

Sensor.TYPE_PROXIMITY 距离

Sensor.TYPE_TEMPERATURE 温度

采样率

SensorManager.SENSOR_DELAY_FASTEST 最快不推荐，耗电最大，算法不好会影响ui性能

SensorManager.SENSOR_DELAY_GAME 实时性较高的游戏使用该级别

SensorManager.SENSOR_DELAY_NORMAL 标准延迟，过低对赛车有跳帧现象

SensorManager.SENSOR_DELAY_UI 用户界面，游戏不推荐，相对省电

注册监听

package cn.itcast.sensor;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 ImageView imageView;private SensorManager manager;private SensorListener listener = new SensorListener();    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                imageView = (ImageView) this.findViewById(R.id.imageView);        imageView.setKeepScreenOn(true);        manager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);    }@Overrideprotected void onResume() {Sensor sensor = manager.getDefaultSensor(Sensor.TYPE_ORIENTATION);//方向传感器 其他一样manager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_GAME);//第3个参数为采样率                super.onResume();}@Overrideprotected void onPause() { //一旦离开前台则取消 因为传感器很耗电manager.unregisterListener(listener);super.onPause();}private final class SensorListener implements SensorEventListener{ private float predegree = 0;//测量到数据后调用此方法               public void onSensorChanged(SensorEvent event) {float degree = event.values[0];//存放了方向值 90RotateAnimation animation = new RotateAnimation(predegree, -degree, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);animation.setDuration(200);imageView.startAnimation(animation);predegree = -degree;}public void onAccuracyChanged(Sensor sensor, int accuracy) {}}        }

main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:gravity="center"    ><ImageView      android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:src="@drawable/zn"    android:id="@+id/imageView"    /></LinearLayout>

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