Question

I am trying to broadcast a toast message with the following code extending Activity. But the broadcast is not received by another Activity, the toast is not displayed. Can someone solve my error? The main activity is SendBroadcast.java

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class SendBroadcast extends Activity {

    public static String BROADCAST_ACTION =
                             "com.unitedcoders.android.broadcasttest.SHOWTOAST";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    public void sendBroadcast(View v) {
        Intent broadcast = new Intent();
        broadcast.setAction(BROADCAST_ACTION);
        sendBroadcast(broadcast);
    }
}

Toast Display Activity is ToastDisplay.java

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;

public class ToastDisplay extends Activity {

    private BroadcastReceiver receiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(getApplicationContext(), "received",
                    Toast.LENGTH_SHORT).show();
        }
    };

    @Override
    protected void onResume() {
        IntentFilter filter = new IntentFilter();
        filter.addAction(SendBroadcast.BROADCAST_ACTION);
        registerReceiver(receiver, filter);
        super.onResume();
    }

    @Override
    protected void onPause() {
        unregisterReceiver(receiver);
        super.onPause();
    }
}

and manifest.xml is as follows

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.broad"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="3" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".SendBroadcast"
            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=".ToastReceiver" >
            <intent-filter>
                <action android:name="com.unitedcoders.android.broadcasttest.SHOWTOAST" />
            </intent-filter>
        </receiver>
    </application>
</manifest>

Answer 1

There can be two types of broacast: static and dynamic. Static are those that are declared in the manifest file. Dynamic can be declared during runtime. You combined these two types of broadcast in one broadcast.

To declare a simple dynamic broadcast you can use the following code (that is based on your code). It will simply display toast message when activity is shown.

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

public class BroadcastTestActivity extends Activity {

    public static String BROADCAST_ACTION =     
                            "com.unitedcoders.android.broadcasttest.SHOWTOAST";
    BroadcastReceiver br = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            Log.w("Check", "Inside On Receiver");
            Toast.makeText(getApplicationContext(), "received",
                    Toast.LENGTH_SHORT).show();
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        IntentFilter filter = new IntentFilter();
        filter.addAction(BROADCAST_ACTION);
        filter.addCategory(Intent.CATEGORY_DEFAULT);
        registerReceiver(br, filter);
    }

    @Override
    protected void onResume() {
        super.onResume();
        sendBroadcast();
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(br);
    }

    public void sendBroadcast() {
        Intent broadcast = new Intent();
        broadcast.setAction(BROADCAST_ACTION);
        broadcast.addCategory(Intent.CATEGORY_DEFAULT);
        sendBroadcast(broadcast);
    }
}

So now instead of showing toast you can call your new activity. The following actions depend on your needs (what you want to do).