Question

I have the following code in an activity to send the user to a different application:

public void goBack(View v) {
    Intent intent = new Intent(Intent.ACTION_MAIN);
    intent.setComponent(new ComponentName("com.example.android.lifecycle", "com.example.android.lifecycle.DialogActivity"));
    startActivity(intent);
}

The manifest file for the application is:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.example.android.lifecycle"
  android:versionCode="1"
  android:versionName="1.0">

<uses-sdk android:minSdkVersion="7" android:targetSdkVersion="15" />
<application android:label="@string/app_name"
             android:icon="@drawable/ic_launcher">

    <activity android:name=".ActivityA"
        android:launchMode="singleTask">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
            <action android:name="com.example.android.lifecycle" />
        </intent-filter>
    </activity>

    <activity android:name=".ActivityB" />

    <activity android:name=".ActivityC" />

    <activity android:name=".DialogActivity"
              android:theme="@android:style/Theme.Dialog">
        <action android:name="com.example.android.lifecycle" />
        <action android:name="android.intent.action.MAIN" />            
    </activity>

</application>
</manifest> 

However, when I click on the button which should send me to the new application, I get a message saying – The application has stopped unexpectedly. Please try again.

What am I doing wrong and how can I rectify this?

Thanks!!

09-27 14:08:42.763: E/AndroidRuntime(286): FATAL EXCEPTION: main
09-27 14:08:42.763: E/AndroidRuntime(286): java.lang.IllegalStateException: Could not execute method of the activity
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.view.View$1.onClick(View.java:2072)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.view.View.performClick(View.java:2408)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.view.View$PerformClick.run(View.java:8816)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.os.Handler.handleCallback(Handler.java:587)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.os.Handler.dispatchMessage(Handler.java:92)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.os.Looper.loop(Looper.java:123)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.app.ActivityThread.main(ActivityThread.java:4627)
09-27 14:08:42.763: E/AndroidRuntime(286):  at java.lang.reflect.Method.invokeNative(Native Method)
09-27 14:08:42.763: E/AndroidRuntime(286):  at java.lang.reflect.Method.invoke(Method.java:521)
09-27 14:08:42.763: E/AndroidRuntime(286):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-27 14:08:42.763: E/AndroidRuntime(286):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-27 14:08:42.763: E/AndroidRuntime(286):  at dalvik.system.NativeStart.main(Native Method)
09-27 14:08:42.763: E/AndroidRuntime(286): Caused by: java.lang.reflect.InvocationTargetException
09-27 14:08:42.763: E/AndroidRuntime(286):  at com.example.myfirstapp.DisplayMessageActivity.goBack(DisplayMessageActivity.java:30)
09-27 14:08:42.763: E/AndroidRuntime(286):  at java.lang.reflect.Method.invokeNative(Native Method)
09-27 14:08:42.763: E/AndroidRuntime(286):  at java.lang.reflect.Method.invoke(Method.java:521)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.view.View$1.onClick(View.java:2067)
09-27 14:08:42.763: E/AndroidRuntime(286):  ... 11 more
09-27 14:08:42.763: E/AndroidRuntime(286): Caused by: java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.MAIN cmp=com.example.android.lifecycle/.DialogActivity } from ProcessRecord{450fce58 286:com.example.myfirstapp/10044} (pid=286, uid=10044) requires null
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.os.Parcel.readException(Parcel.java:1247)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.os.Parcel.readException(Parcel.java:1235)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1298)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1373)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.app.Activity.startActivityForResult(Activity.java:2817)
09-27 14:08:42.763: E/AndroidRuntime(286):  at android.app.Activity.startActivity(Activity.java:2923)
09-27 14:08:42.763: E/AndroidRuntime(286):  ... 15 more

Answer 1

Add Intent.FLAG_ACTIVITY_NEW_TASK and Intent.FLAG_FROM_BACKGROUND flags with intent if you are starting New Application from Background as:

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setComponent(new ComponentName( "com.example.android.lifecycle","com.example.android.lifecycle.DialogActivity"));
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
intent.setFlags(Intent.FLAG_FROM_BACKGROUND);
startActivity(intent);