Develop Reference

Launching Activity from another App? (with AndroidAnnotations)

How can i launch an AndroidAnnotations Activity_ inside of an App (main)
since external Activity (another App).
this is my current code:
Intent codeScannerActivity = new Intent(PACKAGE, CODE_SCANNER_ACTIVITY);
codeScannerActivity.putExtra("codeScannerType", CameraUtils.CODE_SCANNER_SINGLE);
startActivityForResult(codeScannerActivity, Core.ActivityResult.RequestCode.CODE_SCANNER);
where PACKAGE = "main.app.package"
and CODE_SCANNER_ACTIVITY = PACKAGE + ".activity.MyActivity_"
but logs throws:
android.content.ActivityNotFoundException: No Activity found to handle Intent { act=main.app.package dat=main.app.package.activity.MyActivity_ (has extras) }
Activity is defined in the Manifest's Main App with the Class "etc.MyActivity_".

You are constructing the Intent incorrectly. For the constructor you are using, the first parameter is interpreted as an "action" and the second as a URI. The error says that there is no activity which can respond to the action "main.app.package" and the URI "main.app.package.activity.MyActivity_".
To fix the problem, first read Starting Another Activity and the Intent javadocs from the Android Developer site. Especially look at the documentation for the available constructors. There might be one more appropriate for your purposes than the one you are trying to use. The Intent documentation has a list of standard Activity actions. If you want to start a specific activity, you should use Intent (Context packageContext, Class<?> cls):
Intent intent = new Intent(this, main.app.package.activity.MyActivity_.class);

I was creating wrong the Intent, this is the right way:
Intent codeScannerActivity = new Intent();
codeScannerActivity.setComponent(new ComponentName(PACKAGE, CODE_SCANNER_ACTIVITY));
codeScannerActivity.putExtra("codeScannerType", CameraUtils.CODE_SCANNER_SINGLE);
startActivityForResult(codeScannerActivity, Core.ActivityResult.RequestCode.CODE_SCANNER);

Launch an activity of an application from a different application on Android

I need to launch an activity (not the main activity) of an application from an application I have made. The activity I want to launch is proprietary, hence, I cannot make any changes to its code(or manifest).
For example: I want to launch somebody's Facebook profile from my own application. A normal intent to facebook from my app would open the 'newsfeed'(which I don't want). I want to know how to access any other activity.
Thanks in advance!
The little code I have:
String PACKAGE="com.facebook.katana";
Intent launchIntent = getPackageManager()
.getLaunchIntentForPackage(PACKAGE);
startActivity(launchIntent);

To launch specific activity you need to use explicit intent. Or use implicit intent with action if you know what action that activity answers to.
To use explicit intent you can do the following (provided you call it from the activity):
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.package.name", "com.package.name.ActivityName"));
if(getPackageManager().resolveActivity(intent, 0) != null) {
startActivity(intent);
} else {
Toast.makeText(this, "No app installed that can perform this action", Toast.LENGTH_SHORT).show();
}
You can also add flags to the intent, add actions and categories. As long as the intent can be resolved as viable intent by the PackageManager, it will launch the activity.
Now...
The question about facebook profile, is a different one.
Perhaps, the best way to achieve that would be to use intent with action VIEW and povide Intent.setData with uri to the profile page. That should also be checked for possibility of being resolved correctly. And then will launch the chooser of all supported activities to open it, which should include facebook application. It is then up to user to open the intent using Facebook app or launcher.

Error: Trying to pass data between activities in different applications of Intent in Android

** Code used in First/Parent Activity of Application A
Intent LaunchIntent = new Intent();
LaunchIntent.putExtra("ComingFrom", "RentsComments");
LaunchIntent.setClassName("packageNameOfApplicationB", "activityName");
startActivityForResult(LaunchIntent, requestCode);
**Code used in SecondActivity:**
Intent launchIntent = new Intent();
launchIntent.putExtra("transaction_data_id", 123456);
launchIntent.putExtra("transaction_data_authorised_amount", 10.0);
launchIntent.putExtra("transaction_data_status", "finished");
// launchIntent.setClassName("packageName", "fullQualifiedActivityNameInPackage");
setResult(2520,launchIntent);
finish();
I couldn't understand why the onActivityResult in ParentActivity is not firing once after calling it

You cannot use startActivityForResult() when the target has the singleTask launch mode. Or rather, you can, but you will get an immediate RESULT_CANCELLED, not the actual result.
From the documentation:
Note that this method should only be used with Intent protocols that
are defined to return a result. (...) For example, if the activity you
are launching uses the singleTask launch mode, it will not run in your
task and thus you will immediately receive a cancel result.
Unfortunately, there is no workaround for this (AFAIK).

Android Intent To Open Application Not Working

I am trying to open the Google Voice Search Application
Intent i;
PackageManager manager = getPackageManager();
try {
i = manager.getLaunchIntentForPackage("com.google.android.voicesearch");
if (i == null)
throw new PackageManager.NameNotFoundException();
i.addCategory(Intent.CATEGORY_LAUNCHER);
startActivity(i);
} catch (PackageManager.NameNotFoundException e) {
}
This does not launch the voice search application,
however if I use com.google.android.apps.maps as the package name then the Google Maps app is opened.
I don't understand why Voice Search is not opening, even though the package name is correct.
Solution
Intent intent = new Intent(RecognizerIntent.ACTION_WEB_SEARCH);
startActivity(intent);
Please see
Launch Preinstalled App from activity (Google Voice Search) Android for more information on the solution.
Thank you.

As you can read here, getLaunchIntentForPackage (String packageName)
Return a "good" intent to launch a front-door activity in a package [...]
The current implementation will look first
for a main activity in the category CATEGORY_INFO, next for a main
activity in the category CATEGORY_LAUNCHER, or return null if neither
are found.
so, in the intent, the category will already be set. If you manually change it, probably you are breaking the intent, since the category could not be the correct one that the manager found.
so, just remove the line
i.addCategory(Intent.CATEGORY_LAUNCHER);

open android own launcher from my application

hi Its been 2 days looking for this simple problem. I want to launch Android own launcher from my application EVEN if its not set as default.
final PackageManager packageManager=getPackageManager();
Intent intent = packageManager.getLaunchIntentForPackage("com.android.launcher");
this return null for Android own launcher but if I try custom launcher is give me successfully

Found the solution, after investigating source code of getLaunchIntentForPackage. As per documentation,
The current implementation will look first for a main activity in the
category CATEGORY_INFO, next for a main activity in the category
CATEGORY_LAUNCHER, or return null if neither are found.
So, the function don't look for CATEGORY_HOME, i rewrote it in following way, it worked perfectly.
Intent intentToResolve = new Intent(Intent.ACTION_MAIN);
intentToResolve.addCategory(Intent.CATEGORY_HOME);
intentToResolve.setPackage("com.android.launcher");
ResolveInfo ri = getPackageManager().resolveActivity(intentToResolve, 0);
if (ri != null)
{
Intent intent = new Intent(intentToResolve);
intent.setClassName(ri.activityInfo.applicationInfo.packageName, ri.activityInfo.name);
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
startActivity(intent);
}

Are you sure the default Google Android Launcher being installed on your device? If not, then it's truly NULL.