i'm trying to use in my project a broadcast receiver which listens to battery status of charging/not charging and throw a toast in each of the options .
every time i change the charger status in the app ,the app crash.
(if i start the app with the charger connected it's show me the right toast
but when i uncharge the phone the app crashes)
here is the code
thanks in advance
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
Intent batteryStatus = this.registerReceiver(null, ifilter);
int status = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
boolean isCharging = status == BatteryManager.BATTERY_STATUS_CHARGING ||
status == BatteryManager.BATTERY_STATUS_FULL;
if(isCharging==true){
Toast.makeText(this, "Charging", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(this, "Charger not connected", Toast.LENGTH_SHORT).show();
UPDATE
i'm having an hard time to understand what i suppose to do.
i'm pretty new so be patient with me :)
here is the code i made
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkBatteryState(null);
public void checkBatteryState(View sender) {
IntentFilter filter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
Intent batteryStatus = registerReceiver(null, filter);
int chargeState = batteryStatus.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
String strState;
switch (chargeState) {
case BatteryManager.BATTERY_STATUS_CHARGING:
case BatteryManager.BATTERY_STATUS_FULL:
strState = "charging";
Toast.makeText(this, strState, Toast.LENGTH_LONG).show();
break;
default:
strState = "not charging";
Toast.makeText(this, strState, Toast.LENGTH_LONG).show();
}
}
}
http://www.vogella.com/tutorials/AndroidBroadcastReceiver/article.html
is this what you're using?
Maybe you haven't ensured your Intent is sticky.
My advice would be not to use a registerreceiver with a null argument.
Try this method for creating a broadcastreceiver:
How to send data to another app which is not started
put your Toasts in the onReceive() function.
The code is not actually registering a receiver, just getting a sticky broadcast. If the broadcast has never been sent the this will return null which will cause a NPE in the remaining code.
Related
I'm trying to send messages through in built sms app through Intent. Its working fine. Here is my code
public class Main_Act extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button startBtn = (Button) findViewById(R.id.button);
startBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
if(sendSMS()) {
Intent intent = new Intent(Main_Act.this, Sample.class);
startActivity(intent);
}
}
});
}
protected boolean sendSMS() {
ArrayList<String> nums = new ArrayList<String>();
nums.add("111111111");
nums.add("222222222");
Log.i("Send SMS", "");
Intent smsIntent = new Intent(Intent.ACTION_VIEW);
smsIntent.setData(Uri.parse("smsto:"));
smsIntent.setType("vnd.android-dir/mms-sms");
smsIntent.putExtra("address" ,nums);
smsIntent.putExtra("sms_body" , "Test ");
try {
startActivity(smsIntent);
finish();
return true;
}
catch (android.content.ActivityNotFoundException ex) {
Toast.makeText(Main_Act.this,
"SMS faild, please try again later.", Toast.LENGTH_SHORT).show();
return false;
}
}
}
But the problem is it gets navigated to another activity without clicking send button in sms application. It should goto another activity only after clicking the send button in messaging app. Can anyone help me with this problem, Thanks in advance.
Let's clear out a slight misunderstanding in your code:
You should not try to start both intents in the same part/run of the code as you do here.
A startActivity will not execute directly going to the activity and then return to the same place in the code when activity execution finishes. In stead it asynchronously queues the intent for execution. Then your code queues another intent for execution. After the current code finishes (in this case when the button onClick() method ends) Android queue mgmt can start picking off the queue. Probably the first intent is executed shortly and then directly overrun by an immediate execution of the second.
So what happens in summary is that you first add one intent to the queue in sendSMS and then add intent 2 to the queue in onClick, before leaving. Now both the intents are executed.
What you need to do is to change the sendSMS code to something like:
Intent smsIntent = new Intent(Intent.ACTION_VIEW);
smsIntent.setData(Uri.parse("smsto:"));
smsIntent.setType("vnd.android-dir/mms-sms");
smsIntent.putExtra("address" ,nums);
smsIntent.putExtra("sms_body" , "Test ");
// To force the SMS app to return immediately after sent SMS
smsIntent.putExtra("exit_on_sent", true);
startActivityForResult(smsIntent, MY_SMS_REQUEST_RESPONSE_CODE);
Note the startActivityForResult() method that indicates that we expect Android to return and the "exit_on_sent" extra, to force a swift return.
MY_SMS_REQUEST_RESPONSE_CODE is just any random code you select to recognize the returning result in the callback method (even if you currently do not expect any other returning results, you may have some in the future).
Next thing to do is to remove the second intent creation and queuing. In stead you implement the following callback method (added to this activity):
#Override
protected void onActivityResult(
int callbackIdentifier, int resultCode, Intent intent) {
// Is this the expected sendSMS callback ?
if (callbackIdentifier== MY_SMS_REQUEST_RESPONSE_CODE) {
if (resultCode == RESULT_OK) {
// Continue where you left off (e.g. execute intent 2)
Intent intent = new Intent(Main_Act.this, Sample.class);
startActivity(intent);
} else if (resultCode == RESULT_CANCELED) {
// Error handling/retrying etc
}
}
// Support inherited callback functions
super.onActivityResult(callbackIdentifier,resultCode,intent);
}
Note: if you want to pass data and type don't call method separately because will delete each other you must pass it in one method
wrong
smsIntent.setData(Uri.parse("smsto:"));
smsIntent.setType("vnd.android-dir/mms-sms");
true
smsIntent.setDataAndType(Uri.parse("smsto:"),"vnd.android-dir/mms-sms");
I have a broadcastreceiver created in my Service class.
It is set to react to this action: WifiManager.SCAN_RESULTS_AVAILABLE_ACTION
So basically everytime I do a method call of wifi.startScan(); , and the results become available, the broadcastreceiver's onReceive method does its thing.
My issue is that I need to process those scan results and its likely not good practice to do so much in the broadcastreceiver. I want to do all the calculations back in my service class but I need to somehow access the ScanResults.
Any sort of help with this? As it is much needed.
Here is a simplified version of my code conveying the purpose of my broadcastreceiver:
Snippet from my Service class:
IntentFilter i = new IntentFilter();
i.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION); //reacts to the scan results being available
registerReceiver(mybroadcast,i);
wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if(!wifi.isWifiEnabled()){ // if wifi is not enabled
toast = Toast.makeText(getApplicationContext(), "Wifi is off. Please turn it on.", Toast.LENGTH_LONG);
toast.show();
//wifi.setWifiEnabled(true);
//startActivity(backIntent);
}
else
{
wifi.startScan(); //what the receiver is going to react to
}
Code for my receiver:
private final BroadcastReceiver mybroadcast = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//gets the scan results
wifi = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);
List<ScanResult> scans = wifi.getScanResults();
// do some work here...
}
}
You can try adding an handler to service for ex:
private final Handler handler = new Handler() {
public void handleMessage(Message msg) {
String aResponse = msg.getData().getString("message");
if ((null != aResponse)) {
// ALERT MESSAGE
Toast.makeText(getBaseContext(),
"Server Response: " + aResponse, Toast.LENGTH_SHORT)
.show();
} else {
// ALERT MESSAGE
Toast.makeText(getBaseContext(),
"Not Got Response From Server.", Toast.LENGTH_SHORT)
.show();
}
}
};
And send a message to it in OnReceive of your BroadcastReceiver:
Message msgObj = handler.obtainMessage();
Bundle b = new Bundle();
b.putString("message", msg);
msgObj.setData(b);
handler.sendMessage(msgObj);
I need my application to give a notification whenever WiFi goes offline.
I got it to give a notification every time the WiFi connection changes. But I need it to only give a notification when it goes offline.
Also it gives a notification on start-up (of the application).
My question is, how do I alter the code to only give a notification when WiFi goes offline? Now it gives a notification when it goes offline, online and on start-up.
The code:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.registerReceiver(this.mConnReceiver,
new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
setContentView(R.layout.activity_main);
}
private BroadcastReceiver mConnReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);
NetworkInfo currentNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
NetworkInfo otherNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO);
if(currentNetworkInfo.isConnected()){
}else{
showNotification();
}
}
};
Try like this:
if(currentNetworkInfo != null &&
currentNetworkInfo.getType() == ConnectivityManager.TYPE_WIFI &&
currentNetworkInfo.getState() == NetworkInfo.State.DISCONNECTING) {
showNotification();
}
There are also other possible states(such as NetworkInfo.State.DISCONNECTED, maybe that is what you want), you can find the full list here:
http://developer.android.com/reference/android/net/NetworkInfo.State.html
I am planning on sending SMS messages in my app. I have this code so far:
private void sendMessage(String number, String message ){
dlg.setCancelable(false);
dlg.setMessage("Sending...");
InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(etText.getWindowToken(), 0);
etText.setText("");
dlg.show();
SmsManager sms = SmsManager.getDefault();
Intent sendingIntent = new Intent(Intent.ACTION_SEND);
sendingIntent.putExtra("number", number);
sendingIntent.putExtra("message", message);
PendingIntent sendPI = PendingIntent.getBroadcast(this, 0, sendingIntent, PendingIntent.FLAG_ONE_SHOT);
sms.sendTextMessage(number, null, message, sendPI, null);
}
My Receiver:
public class SMSSenderReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
int resultCode = this.getResultCode();
String number = intent.getExtras().getString("number");
String message = intent.getExtras().getString("message");
ContentValues val = new ContentValues();
val.put("address", number);
val.put("body", message);
switch(resultCode){
case Activity.RESULT_OK:
context.getContentResolver().insert(Uri.parse("content://sms/sent"), val);
if (MessageListActivity.dlg != null){
if (MessageListActivity.dlg.isShowing()){
MessageListActivity.dlg.dismiss();
}
}
}
}
}
In my methods for my activity:
SMSSenderReceiver receiver = new SMSSenderReceiver();
#Override
public void onCreate(Bundle b){
this.registerReceiver(receiver, new IntentFilter(Intent.ACTION_SEND));
}
#Override
public void onResume(){
super.onResume();
this.registerReceiver(receiver);
}
#Override
public void onStop(){
super.onStop();
this.unRegisterReceiver(receiver);
}
#Override
public void onPause(){
super.onPause();
this.unRegisterReceiver(receiver);
}
Now the problem is that when I send a message with my phone screen on, it does fine by dismissing the dialog and putting the message into the sent box when it is sent, but when I try to send a message and immediately turn off my screen it sends the message, but doesn't dismiss the dialog nor put the message into the sent folder. I know this has something to do with life cycles of the activity, but I'm not sure what to do with the onPause and onResume functions. If I don't unregister the receiver when the phone turns off then I get an error that the receiver has already been leaked error. Is there anyone that knows of a way of receiving the broadcast when my phone is off? Or of a way for getting the ACTION_SEND broadcast through the manifest?
Turning off screen will always call onStop(), but not with onDestroy(). onDestroy() could be called in case the system is losing memory… I think you can unregister the receiver in onDestroy()…
I created my lockscreen application that trigerred by a SMS.. i have ListenSMS class that always listen for incoming SMS. Here's the code :
for (SmsMessage message : messages) {
String tempMessage[] = message.getDisplayMessageBody().toString().split(" ");
//checking command dan password
if (tempMessage[0].toString().equalsIgnoreCase("andro-lock") && tempMessage[1].toString().equals(tempPassword.toString())) {
//Toast.makeText(ListenSMSservice.this, "Menjalankan command andro-lock", Toast.LENGTH_LONG).show();
openDatabase();
updateStatusL();
Intent myIntent = new Intent(ListenSMSservice.this,LockScreenForm.class);
myIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplication().startActivity(myIntent);
}
else if (tempMessage[0].toString().equalsIgnoreCase("andro-unlock") && tempMessage[1].toString().equals(tempPassword.toString())) {
//Toast.makeText(ListenSMSservice.this, "Menjalankan command andro-unlock", Toast.LENGTH_LONG).show();
openDatabase();
updateStatusNL();
Intent myIntent = new Intent(ListenSMSservice.this,LockScreenForm.class);
myIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
Bundle myKillerBundle = new Bundle();
myKillerBundle.putString("kill","1");
myIntent.putExtras(myKillerBundle);
getApplication().startActivity(myIntent);
}
}
If ListenSMS service has received an andro-lock command, it will go to the lockscreen.java and will go to the lockscreen.java with intent extra (putExtra) kill when it receive command andro-unclock. Here's my lockscreen.java:
public class LockScreenForm extends Activity implements OnClickListener {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.lockscreen);
Bundle extra = getIntent().getExtras();
if (extra == null) {
return;
}
//Toast.makeText(this, extra.getString("kill"), 1).show();
else if(this.getIntent().getExtras().getString("kill").equalsIgnoreCase("1")) {
try {
Toast.makeText(this, "extra accepted", 1).show();
finish();
} catch (Exception e) {
// TODO: handle exception
Toast.makeText(this, e.getMessage(), 1).show();
}
}
}
}
I want to close my locksreen.java when my ListenSMS service has received "andro-unlock" command, so I put extra on intent "kill" and check it in lockscreen.java. This lockscreen.java can check the extra intent and can display a toast "extra accepted" but can close the lockscreen activity with finish().
My assumption is for now that Intent.FLAG_ACTIVITY_NEW_TASK is duplicating a locksreen activity. So it will create a double lockscreen activity and the finish method is closing another lockscreen.java that started by Intent.FLAG_ACTIVITY_NEW_TASK. That's only assumption. Am i wrong? Please correct me.
Has anyone know how to solve my problem? I really want that "andro-unlock" command can close the lockscreen activity and need it works for my college final project. Please help.
From http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_NEW_TASK:
When using this flag, if a task is already running for the activity you are now starting, then a new activity will not be started; instead, the current task will simply be brought to the front of the screen with the state it was last in. See FLAG_ACTIVITY_MULTIPLE_TASK for a flag to disable this behavior.
I expect your problem is somewhere else. I'd suggest having the lockscreen Activity register a BroadcastReceiver, and then when the unlock message is received send an Intent that the BroadcastReceiver will catch. The Activity can then cleanly exit.
Try this: Intent.FLAG_ACTIVITY_NEW_TASK