2）具體代碼如下
[java] view
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package com.example.androidapp;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
private SensorManager mSensorManager=null;
private Sensor mSensor=null;
private TextView textView1=null;
private Button button1=null;
private Button button2=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView1=(TextView)findViewById(R.id.textView1);
/*獲取系統服務（SENSOR_SERVICE）返回壹個SensorManager對象*/
mSensorManager=(SensorManager)getSystemService(SENSOR_SERVICE);
/*通過SensorManager獲取相應的（溫度傳感器）Sensor類型對象*/
mSensor=mSensorManager.getDefaultSensor(Sensor.TYPE_TEMPERATURE);
/*註冊相應的SensorService*/
button1=(Button)findViewById(R.id.button1);
button1.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View arg0) {
mSensorManager.registerListener(mSensorEventListener, mSensor
, SensorManager.SENSOR_DELAY_NORMAL);
}
});
/* 銷毀相應的SensorService
* 很關鍵的部分，註意，說明文檔中提到，即使Activity不可見的時候，感應器依然會繼續工作
* 所以壹定要關閉觸發器，否則將消耗用戶大量電量*/
button2=(Button)findViewById(R.id.button2);
button2.setOnClickListener(new Button.OnClickListener() {
@Override
public void onClick(View v) {
mSensorManager.unregisterListener(mSensorEventListener, mSensor);
}
});
}
/*聲明壹個SensorEventListener對象用於偵聽Sensor事件，並重載onSensorChanged方法*/
private final SensorEventListener mSensorEventListener=new SensorEventListener() {
@Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType()==Sensor.TYPE_TEMPERATURE){
/*溫度傳感器返回當前的溫度，單位是攝氏度（°C）。*/
float temperature=event.values[0];
textView1.setText(String.valueOf(temperature)+"°C");
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}