Tutorial – How to start a new Activity
For starting a new Activity we need to use intent, which is an abstract description of an operation to be performed.
http://developer.android.com/reference/android/content/Intent.html
Suppose we are on Activity named ‘CurrentActivity‘ and on certain event (like button click..) we want to start a new Activity named ‘NextActivity’
We can create a new activity as follows.
public class NextActivity extends Activity {
//Your member variable declaration here
// Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState) {
//Your code here
}
}
After we have created the new Activity, we have to register it in file ‘AndroidManifest.xml’.
For registering we have to create an entry in ‘AndroidManifest.xml’ as
<activity android:name=".NextActivity" android:label="@string/app_name"> </activity>
Note that here we have not used intent filter , since we are going to use an explicit intent, the syntax of intent filter is
<intent-filter> <action android:name="<action here>"/> <category android:name="<category here>"/> </intent-filter>
Here,
action — The general action to be performed
category — Gives additional information about the action to execute. For example, CATEGORY_LAUNCHER means it should appear in the Launcher as a top-level application, while CATEGORY_ALTERNATIVE means it should be included in a list of alternative actions the user can perform on a piece of data.
Note: you can also use application tab below the ‘AndroidManifest.xml’ file, and in ‘Application Nodes’ section click
‘Add’ button as shown in figure below and select the activity .
Application Node-Add Activity
Next you can start this activity on any event as follows
Intent myIntent = new Intent(CurrentActivity.this, NextActivity.class);
CurrentActivity.this.startActivity(myIntent);
Here, you have to create and intent with CurrentActivity.this as first parameter
and the the next activity as second parameter.
After you have created the intent, you can start the new activity by calling
startActivity, on current Activity, with the created intent as parameter.
Thanks man. That is what I needed
What is the best to pass a parameter to the new Activity?
Bonjour,
thank you for short but sweet tutorial.
Merci.
@Nils Thorell
Hi Nils,
Suppose you want to pass parameters from an Activity ‘FirstActivity’ to another Activity ‘SecondActivity’.
We can use bundle to pass parameters from ‘FirstActivity‘ to ‘SecondActivity‘. And then add this bundle to the intent, you are using to initiate activity ‘SecondActivity‘, as:
Intent intent = new Intent(FirstActivity.this,SecondActivity.class);
//Next create the bundle and initialize it
Bundle bundle = new Bundle();
//Add the parameters to bundle as
bundle.putString(“NAME”,”my name”);
bundle.putString(“COMPANY”,”wissen”);
bundle.putInt(“AGE”,”22″);
//Add this bundle to the intent
intent.putExtras(bundle);
//Start next activity
FirstActivity.this.startActivity(intent);
Now in ‘SecondActivity‘ we can retrieve the parameters values as:
//First Extract the bundle from intent
Bundle bundle = getIntent().getExtras();
//Next extract the values using the key as
String name = bundle.getString(“NAME”);
String company = bundle.getString(“COMPANY”);
String age = bundle.getInt(“AGE”);
Wonderful article! I have some questions though, it seems like the explicit intent is not specified in the manifest, but in the java code instead? Is that the best way to set up all explicit intents?
I need to have one activity start another activity, should I do that only with an explicit intent? Because right now I do have an intent filter in my manifest for this application (see below).
Notice how it has both intent.action.MAIN and intent.action.LAUNCHER. Would CATEGORY_ALTERNATIVE also apply to an app (for example, one choice of many to perform is to launch this activity) or does it just apply to data? Thanks!
Sorry, it cut out my manifest. Let me try again:
activity android:name=”.MainMenu”
android:label=”@string/app_name”
intent-filter
action android:name=”android.intent.action.MAIN”
category android:name=”android.intent.category.LAUNCHER”
/intent-filter
/activity
@tinyang
Hi tinyang,
The activity tag you post contains an action ‘MAIN’ and category ‘LAUNCHER’.
This intent filter action ‘MAIN’ and category ‘LAUNCHER’, will create and icon of your application in the android device menu. and clicking on it will launch that activity and so is required.
Also the intent-filter of ‘MAIN’ and ‘LAUNCHER’ should be in one activity only, otherwise then number of times this intent-filter appears in AndroidManifest.xml , that many times the icon will appear on the device menu.
Hi,
It is grateful article. It helps me a lot. Thank you very much…….
Hi. Great tutorial.
@zeeshan
this stuff helps me a lot!
Thank you !
Thank you so much for this! Because of this article, I learned in five minutes what I couldn’t learn in hours of digging through the Android documentation. You rule!
Don’t forget to add
Looper.prepare();
before making the new Intent, in the case you are creating the Intent into a Thread.
Thank you very much for this how-to !
Great tutorial.
Thank you very much.
Very handy n usefull tut
Thanks a tonne !
Thanks for explaining it.
THX!!
Very cool and simple tutorial!!
This is a really cool article …but i m facing one problem my application contains many screens which i broke up into activities… now using this approach suppose i create first splash screen which does the initialization tasks.. then i load the next activity…. but now if the user presses the back button the splash screen is appeared again and user can do nothing except quiting it….
how should i handle this specific thing ….thanx again
Very simple and usefull article. Thanks
@Yacir M Turk
Yacir,
You need the splash screen to tell the system that it’s finished and to be removed from the activity stack:
// in your splash screen activity
Intent myIntent = new Intent(SplashScreen.this, NextActivity.class);
startActivity(myIntent);
finish(); // clears the splash screen from the stack
Check out the Forwarding example in the android sdk samples.
Hi,
can anyone help me in this Q’s asked me in a interview ..
How to start another activity without knowing the next activity class name .. for example . in the activity when we click on the url , it directs to the browser , something like that . hope am clear in asking the Q .
thanks
regards,
Sheik
Actually, it’s very good!
great article…but can you tel me how to return back to the main activity after completing the next activity…
i am planning to code an application that involves different activites and returning back to main activity after the sub activity are complete..please guide..thanks
Also..i want to pass objects through the bundle stuff…is that possible…?? pleaset let me know..thanks
raqz, you should be able to simply “finish();” in your next activity when it has completed, and whatever activity was before it should come to the front.
As to passing objects, you need to make them Parcelable. Then you can use bundle.putParcelable() and bundle.getParcelable()
Tank u so much, it was so useful and just i wanted
Thanks , this was helpful
Hey.. thanks..that got me started with Android Intents
Wonderful tutorials………….It saved my time….Thanks
Its very good tutorials and I have got relief from my headache and saved my time .
And here i’m having some doubts on Android
I’m new to android .
what and all my doubts are :
1.) CAN I Split the my web page with different different parts?
like javascript frames and frameset.
2.) if 1 Q is possible then .I have some buttons at my left panel with vertical layout ..and some buttons at top level with Horizontal layout.
And if i click any buttons from either Horizontal Layout or Vertical layout..then hit ill hit server and get the data,that data would be display center of my web page without reloading ..my top
horizontal/left vertical layout…
I hopes my questions are clear and i can get rely soon.
Thanks,
Sevens.
Thanks a lot for that!! That’s absolutely brilliant!
Nice one.
Thank you for the short tutorial.But i face a problem.My current activity is playing audio and i want to start another activity in the middle of the play and i also want to hear the music while doing the second activity(i.e two activities simultaneously).But an error msg comes.Can any one help me?
Hey dude i can’t star a new activity from an AlertDialog, y get the NullPointerException in starActivity while i tring, could you help me please??