Android application without GUI

Question

I have been developing a simple application without UI using broadcast receiver.

The app doesn't contain any ACTIVITIES.

I have given necessary permissions.

I took the code from this url:http://developerandro.blogspot.in/2013/09/check-internet-connection-using.html

The app shows a toast "Not connected to internet" when I click change wifi state. It's working correctly.

But my question is There is an activity registered in my manifest file which I don't have. So I delete those lines from my manifest. Then no toasts are shown and I checked the logs too. No output on changing wifi state.

Why this happened? Please help me guys...

Here is the manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcast_internetcheck"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.broadcast_internetcheck.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver
            android:name="com.example.broadcast_internetcheck.NetworkChangeReceiver"
            android:label="NetworkChangeReceiver" >
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
                <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
            </intent-filter>
        </receiver>
    </application>

</manifest>

Here is my Broadcastreceiver class:

public class NetworkChangeReceiver extends BroadcastReceiver{

  @Override
     public void onReceive(final Context context, final Intent intent) {

         String status = NetworkUtil.getConnectivityStatusString(context);
          /*Above line will return the status of wifi */
         Toast.makeText(context, status, Toast.LENGTH_LONG).show();

     }
}

you mean you are not able to connect to internet ?? is that so? — Rajendra arora, Feb 14 '14 at 06:43
that's not my situation, I need a simple toast when I change my wifi state. — GOBINATH.M, Feb 14 '14 at 06:45
So you want to make toast button, i don't your code but i'll make a simple Toast button for you? — Rajendra arora, Feb 14 '14 at 06:46
As your question, it's because the activity hold the showing Toast function, when the activities hasn't been launched, it will not show Toast. You can write a service to do so without any activity. — user2652394, Feb 14 '14 at 06:47
@user2652394 the toast is shown from BroadcastReceiver class, in onReceive method. — GOBINATH.M, Feb 14 '14 at 07:05
@user2652394 u r not following me. The above code working correctly. If took off the lines ..., no toast are shown. — GOBINATH.M, Feb 14 '14 at 07:20
@user2652394 bcoz, I have no activities to register in the manifest. — GOBINATH.M, Feb 14 '14 at 07:21

score 8 · Accepted Answer · edited May 23 '17 at 12:33

You will need to create a dummy activity for a Service which will be triggered in the onCreate() of the dummy, maybe a non-UI with finish() .

Without that the required implementation is not possible, esp above Android 3.1.

http://developer.android.com/about/versions/android-3.1.html#launchcontrols
Run only a background service when application start
Start android application without activity
http://commonsware.com/blog/2011/07/13/boot-completed-regression-confirmed.html

And for more on Service:
http://developer.android.com/guide/components/services.html
https://developer.android.com/training/run-background-service/create-service.html
http://www.vogella.com/tutorials/AndroidServices/article.html

Amresh · Answer 2 · 2014-02-14T07:25:06.403

1

You can use service instead. But showing Toast through service bit complicated instead you can show notification through service for No Internet Connection.

edited Feb 14 '14 at 07:25

answered Feb 14 '14 at 06:51

Amresh

2,098
16
20

can u tell me how to notify using service? That'd be great. – GOBINATH.M Feb 14 '14 at 07:02
1

http://stackoverflow.com/questions/21603884/android-notify-from-my-alarm-class/21604104#21604104 – Amresh Feb 14 '14 at 07:07

score 0 · Answer 3 · edited May 23 '17 at 12:16

0

If you don't want any activity check this answer. Actually you would have to create service for this: link

edited May 23 '17 at 12:16

Community

1
1

answered Feb 14 '14 at 06:48

Shahzeb

3,696
4
28
47

Yes, I knew about services. but there should not be any activities. – GOBINATH.M Feb 14 '14 at 06:51

score 0 · Answer 4 · answered Oct 31 '16 at 22:29

0

Create a transparent activity. Launch the toast while the activity is active and immediately finish the activity.

answered Oct 31 '16 at 22:29

brutaxia

1

Android application without GUI

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