我正在开发一个使用服务的应用程序。我希望在手机处于睡眠模式时启动和停止服务。我正在使用以下代码，但它不起作用。
我的状态检查服务代码是
public void onStart(Intent intent, int startd) {
Log.v("check","Services is running");
Log.v("spinner Value","Services is running");
handler.removeCallbacks(sendNetworkStatus);
handler.postDelayed(sendNetworkStatus, 1000);
dataManager = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);
wifimanager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
boolean screenOn = intent.getBooleanExtra("screen_state", false);
if (!screenOn) {
// YOUR CODE
Log.v("Screen","Screen is on>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
/* if(!isMyServiceRunning())
{
startService(intent);
}*/
} else {
// YOUR CODE
// stopService(intent);
Log.v("Screen","Screen is off>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
}
}
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
private Runnable sendNetworkStatus = new Runnable() {
public void run() {
sendNetworkInfo();
handler.postDelayed(this, 5000);
checkstrength(wifiStatus,mobileStatus);
messageshow(response);
Log.v("check","ping the URL again and again");
}
};
/*@Override
public boolean onUnbind(Intent intent) {
handler.removeCallbacks(sendNetworkStatus);
handler = null;
return super.onUnbind(intent);
}*/
private void sendNetworkInfo() {
ConnectivityManager connection = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = connection.getActiveNetworkInfo();
if (null != activeNetwork) {
if(activeNetwork.getType() == ConnectivityManager.TYPE_WIFI)
{//wifiStatus = "Wifi Status: UP";
wifiStatus= getWifiSignalStrengthIndBm();
telephonyManager.listen(phoneStateListener,
PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
}
else{
wifiStatus=0;
}
if(activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE)
{//mobileStatus = "Mobile Status: UP";
message="mobile";
// filter.addAction("mobile");
telephonyManager.listen(phoneStateListener,
PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
}
else{
//mobileStatus=0;
telephonyManager.listen(phoneStateListener,
PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
}
try {
response = Network.ping(url);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else{
mobileStatus = 0;
wifiStatus = 0;
response="-1";
}
intent.putExtra("status", response);
sendBroadcast(intent);
}
public int getWifiSignalStrengthIndBm() {
WifiInfo wifiInfo = wifimanager.getConnectionInfo();
return wifiInfo.getRssi();
}
public void checkstrength(int wifi,int mobile)
{
if(wifi!=0 && mobile!=0)
{
if(wifi<mobile){
response="-2";
wifimanager.setWifiEnabled(false);
InternetControl.EnableInternet(getApplicationContext());
}
}
else if(wifi==0&&mobile<=-111)
{
response="-3";
message="signal Strength is too weak";
}
}
@Override
public void onDestroy() {
handler.removeCallbacks(sendNetworkStatus);
Thread.currentThread().interrupt();
unregisterReceiver(mReceiver);
Toast.makeText(getBaseContext(), "service is destroy", Toast.LENGTH_LONG).show();
super.onDestroy();
}
并记录cat error
09-04 12:46:33.249: E/AndroidRuntime(4177): FATAL EXCEPTION: main
09-04 12:46:33.249: E/AndroidRuntime(4177): java.lang.RuntimeException: Unable to start service com.example.data_connection_monitor.StatusChecker@415923f8 with null: java.lang.NullPointerException
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2390)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.ActivityThread.access$1900(ActivityThread.java:128)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1224)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.os.Handler.dispatchMessage(Handler.java:99)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.os.Looper.loop(Looper.java:137)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.ActivityThread.main(ActivityThread.java:4517)
09-04 12:46:33.249: E/AndroidRuntime(4177): at java.lang.reflect.Method.invokeNative(Native Method)
09-04 12:46:33.249: E/AndroidRuntime(4177): at java.lang.reflect.Method.invoke(Method.java:511)
09-04 12:46:33.249: E/AndroidRuntime(4177): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
09-04 12:46:33.249: E/AndroidRuntime(4177): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
09-04 12:46:33.249: E/AndroidRuntime(4177): at dalvik.system.NativeStart.main(Native Method)
09-04 12:46:33.249: E/AndroidRuntime(4177): Caused by: java.lang.NullPointerException
09-04 12:46:33.249: E/AndroidRuntime(4177): at com.example.data_connection_monitor.StatusChecker.onStart(StatusChecker.java:77)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.Service.onStartCommand(Service.java:438)
09-04 12:46:33.249: E/AndroidRuntime(4177): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2373)
09-04 12:46:33.249: E/AndroidRuntime(4177): ... 10 more
请帮帮我。我是android新手。 在此先感谢!!!!!!!!