I am trying to launch an activity by specifying only its action(custom) defined in its intent filter from an activity in other application. The activity to be launched is the main activity of its application thus have android.intent.action.MAIN & android.intent.category.LAUNCHER set as action and category in its intent filter. Now according to android doc on Intent and Intent Filter, i do not need to specify DEFAULT category at all in this case. But doing the same i am i am unable to launch the activity.
LogCat says, Activity could not be found...
Am i misinterpreting the text or is there something else missing...?
Code, used for calling the activity
Intent i=new Intent();
i.setAction("android.AddressBookV4.firstActivity");
startActivity(i);
Definition of Activity being called in the manifest file
<activity android:name=".AddressBook"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.AddressBookV4.firstActivity" />
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
You need to add the LAUNCHER category to your Intent, since the <intent-filter> says that it matches the following Intents (in pseudocode):
((action IS "android.AddressBookV4.firstActivity")
OR (action IS "android.intent.action.MAIN"))
AND (category IS "android.intent.category.LAUNCHER")
Related
I'm experimenting, specifying my own action for use in an implicit intent. In a single package, I define two activities. ActivityTwo is to be called from onClick() in ActivityOne, using an implicit intent with an action "course.labs.activitylab.MY_ACTION". But I haven't been able to make it work.
In strings.xml:
<string name="myfunnystring">course.labs.activitylab.MY_ACTION</string>
In AndroidManifest.xml:
<activity
android:name=".ActivityTwo"
android:label="#string/title_activity_activity_two" >
<intent-filter>
<action android:name="#string/myfunnystring" />
</intent-filter>
</activity>
In onClick() in the OnClickListener() in onCreate() in ActivityOne.java:
Intent intent = new Intent();
intent.setAction(getString(R.string.myfunnystring));
intent.setFlags(Intent.FLAG_DEBUG_LOG_RESOLUTION);
startActivity(intent);
The program crashes in the emulator, and I find this in the logcat window:
android.content.ActivityNotFoundException: No Activity found to handle Intent { act=course.labs.activitylab.MY_ACTION flg=0x8 }
What am I doing wrong?
Add the default category to your intent filter.
<intent-filter>
<action android:name="course.labs.activitylab.MY_ACTION" />
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
Here's the problem. I have an <activity-alias> in my manifest defined as follows:
<activity
android:name=".HomeActivity"/>
<activity-alias
android:name=".MainActivity"
android:targetActivity=".HomeActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity-alias>
Now, user starts MainActivity using a launcher icon, it forwards to the HomeActivity.
I also have an Intent to start HomeActivity from the navigation drawer. It is started with Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP flags - to reuse existing instance of activity.
The problem is that this does not work as intended and it actually creates a new instance of HomeActivity (even though it is currently on top and visible!).
This happens because an activity backstack contains an entry for .MainActivity, not the HomeActivity it forwarded to in the end.
Question: I suspect this might or might not be the bug in Android, but I have a difficult time of figuring out a decent workaround. Asking for help here! :)
I need only single activity started, and when user selects an item in navdrawer, that single activity should get onNewIntent(), not the new activity spawning!
Getting rid of an activity-alias fixes things, but this is not an acceptable option for me...
Here's the adb dumpsys result after the activity is started from launcher and then user selects 'Home' in navdrawer which starts activity directly, not through the alias (this dump confirms that there are two entries with different names):
Main stack:
TaskRecord{4181c408 #61 A ru.treto.tile U 0}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=ru.treto.tile/.HomeActivity }
Hist #2: ActivityRecord{412514b8 ru.treto.tile/.HomeActivity}
Intent { flg=0x24000000 cmp=ru.treto.tile/.HomeActivity }
ProcessRecord{412b06e0 10165:ru.treto.tile/u0a63}
Hist #1: ActivityRecord{41723200 ru.treto.tile/.MainActivity}
Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=ru.treto.tile/.MainActivity }
ProcessRecord{412b06e0 10165:ru.treto.tile/u0a63}
Instead of referencing your HomeActivity in the classes that are launching it, you'll need to alter those intents to start "MainActivity" instead.
EX:
Intent intent = new Intent();
intent.setClassName(mContext, "ru.treto.tile.MainActivity");
Alternately, if you're using another IntentFilter scheme, you can move those IntentFilter elements to your alias entry in the manifest:
<activity-alias
android:name=".MainActivity"
android:target="ru.treto.tile.HomeActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="ru.treto.tile.ACTION_OF_AWESOME" />
</intent-filter>
</activity-alias>
I'm trying to call main activity using implicit intents. I give both action and category in intent but before starting the activity android system gives me a list of applications to select from for opening the activity.
Code snippet I am using to call the main activity follows:
protected void initiateActivity(int requestCode, String value, String oper) {
Intent i = new Intent("android.intent.action.MAIN");
i.addCategory("android.intent.category.LAUNCHER");
i.putExtra("VALUE", value);
i.putExtra("OPER", oper);
startActivityForResult(i, requestCode);
}
It seems to me that every app in system will be having same action, category combo, hence android is giving me that list of apps to select from. What changes can I make to my Main Activity so that this issue is not seen?
Looks like you might need to separate out with intent-filters. It looks there is a good explanation in this post:
How can I start MAIN activity with the help of <intent-filter>?
Which recommends adding the filters such as these below or you will be calling the launcher:
<activity android:name=".MyActivity"
android:configChanges="orientation|keyboardHidden"
android:windowSoftInputMode="stateHidden"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="com.package.name.MyAction"/>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
I'm developing two applications, AppA and AppB, and I want to start AppB from AppA.
In AppA, I am using
Intent initIntent = getPackageManager().getLaunchIntentForPackage("com.example.appB.ActivityB");
in AppB, I am adding an intent filter to the manifest file :
<activity
android:name="com.example.appB.ActivityB"
android:label="#string/title_activity_init" >
<intent-filter>
<action android:name="com.example.appB.ActivityB" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
But I got a java.lang.NullPointerException on the intent...
Any ideas would be welcome.
Your intent filter isn't complete for this API:
The current implementation looks first for a main activity in the category CATEGORY_INFO, and next for a main activity in the category CATEGORY_LAUNCHER. Returns null if neither are found.
So you need to modify Activity B's intent filter to include:
<action android:name="android.intent.action.MAIN" />
You are trying to specify an Activity in the Intent, even though you are creating a Intent meant to launch a package; this is not neccesary. Simply remove the Activity from your Intent like so:
Intent initIntent = getPackageManager().getLaunchIntentForPackage("com.example.appB");
And then just make sure that you have the following two lines in whichever Activity you wish to start when the application is launched:
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
They should be already be in there for your main Activity, although it looks like you were missing the android.intent.action.MAIN intent filter in your ActivityB.
I have this Activity defined in my AndroidManifest.xml:
<activity
android:name=".Splash"
android:label="#string/app_name"
android:noHistory="true" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
When I am trying to call it in this way:
Intent splashActivity = new Intent("android.intent.action.Splash");
mainAppContext.startActivity(splashActivity);
I get:
android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.Splash }
And when I try to start it in this way:
Intent splashActivity = new Intent("android.intent.action.MAIN ");
mainAppContext.startActivity(splashActivity);
It open a Complete action using dialog with many options there like play store etc.
Please help in starting this Activity.
From some other Activity:
startActivity(new Intent(this, Splash.class));
Intent splashActivity = new Intent("android.intent.action.Splash");
No-no-no! It should to
Intent splashActivity = new Intent(context, Splash.class);
If you use action - it seem that you want activity for some type of action, for example, view webpage on browser.
In your situation you have to use concrete activity and set it to intent
<action android:name="android.intent.action.MAIN" />
this action is not for your app, it is needed to android's launcher, that find activity in your application to launch it
Official documentation about intent mechanism
Where are you trying to launch this activity from? The following lines imply that Splash is your main Activity:
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
Are you trying to launch the Splash Activity from Splash itself? This would be problematic. If you are launching from another Activity then you can use the following to launch Splash:
Intent intent = new Intent();
intent.setClass(YourCurrentActivity.this, Splash.class);
startActivity(intent);
Activity not found exception is occurred when u are trying to use or start activity that is not declared into the Mainfeast.xml file.
And When you want to start any activity then you need to start that activity by using intent. but in android "android.intent.action.Splash" Intent Action exist. And you have declared the following intent filter
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
"android.intent.action.MAIN" this is the action name that indicate the this is the activity to be started first. and android send this intent and an activity that is registered with this intent action is the first activity to be started first.
So to start splash activity you doesn't need any intent. You just need to simply run this project. but If u want to Start Another activity from splash actiivty then u need to do following things.
Intent intent = new Intent(Context, ActivityName.class);
startActivity(intent);
or
startActivityForResult(intent, requestCode);
and remember that You have to declare that activity into the mainfeast.xml