Develop Reference

Android open Contacts app (not choose a contact)

I want to give the user possibility to open Contacts app from my app, so he can edit them, export etc. What I DON'T WANT is a contact picker where the user selects a contact. I need only to somehow open the Contacts app from my app. How Can I do it ? Intent ?

The following snippet will do what you want .
Intent intent = new Intent(Intent.ACTION_VIEW, ContactsContract.Contacts.CONTENT_URI);
startActivity(intent);

This should work as expected.
Intent intent = new Intent();
intent.setComponent(new ComponentName(
"com.android.contacts"
,"com.android.contacts.DialtactsContactsEntryActivity");
startActivity(intent)

Open specific Settings-page programmatically

Is there any way to, in my app, to redirect a user to a specific settings 'page'? My app works as a lock screen app, so I want to be able to redirect the user directly to the "Lock Screen" section of the Android settings. (Preferably via a button or something similar)

ACTION_SECURITY_SETTINGS Intent:
Intent intent = new Intent(Settings.ACTION_SECURITY_SETTINGS);
startActivity(intent);
For complete Settings Intents

I managed to find the correct answer in an old Stackoverflow-post from a while back. The code snippet now looks like this:
Intent intent = new Intent(DevicePolicyManager.ACTION_SET_NEW_PASSWORD);
startActivity(intent);

val intent = Intent(Settings.ACTION_SECURITY_SETTINGS)
intent.flags =
Intent.FLAG_ACTIVITY_NEW_TASK or
Intent.FLAG_ACTIVITY_CLEAR_TOP
startActivity(intent)
Note the flags. These are optional, but necessary to remove the previous settings screen from the screen if it was previously open (this is needed if your application wants to open multiple settings screens).

How to remove application history in Android?

I have an application in which I want to show a custom activity(Access Denied) when user try to share an image.
When I am trying to share an image from default 'Downloads' application (For eg: share image through default message/gmail application) the custom activity is showed and exits 'Downloads' application.But next time when I launch the 'Downloads' application and press on an image the previously created draft mail/message is shown as the top activity.So it shows the custom activity always.
Launched the 'Downloads' application by using this intent.
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setComponent(new ComponentName(packagename,className));
startActivity(intent);
How can I fix this? I want to launch the 'Downloads' application as new (removing history of gmail/message etc.) every time.

Please try below code
Intent intent = new Intent(ClassA.this, ClassB.class);
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);

Android intent chooser does not display list if earlier intent is not finished

With the code below I share some text from my app via an intent chooser. My problem is that if I for example choose to share the text as a message and when in the message app I just hit the home button and bring my app back to front. Then when I try to start a new intent chooser it immediately sends me back to the unfinished message app. I would rather that it forgot all about that and presented me with the list of choices again.
Is there a way to make it forget the old choice?
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("text/plain");
intent.putExtra(Intent.EXTRA_TEXT, text);
startActivity(Intent.createChooser(intent, "Share text as..."));

Add the following
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);

Accessing Android Inbox/Messaging from Activity?

Is it possible to open up the default Android Messaging activity from inside an activity you write yourself? Like for example: I press a "Mail" button inside my program, and it opens the Android Messaging app just like as if I was to press the Messaging icon on the main screen.
I did something similar to this with the Contacts activity, but only the contact list comes up, no extra functionality like Adding/Modifying/Deleting, etc.
Any ideas?
edit: I found this way to open the "Compose New Message" Activity, I just need to back it up a step. Does anyone know the correct MIME type instead of this one?
Intent sendIntent = new Intent(Intent.ACTION_VIEW);
sendIntent.setType("vnd.android-dir/mms-sms");
m_activity.startActivity(sendIntent);

This starts the messaging app from another app:
Intent intent = new Intent("android.intent.action.MAIN");
intent.setComponent(new ComponentName("com.android.mms","com.android.mms.ui.ConversationList"));
startActivity(intent);
Just put it inside a button listener or whatever user input you want to open it from.
Enjoy :-)

If you want to open the messaging app to view messages and not for sending a message, this should do the job:
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setPackage("com.google.android.apps.messaging");
startActivity(intent);