So I was wondering if adding multiple activities in my app, do each require a manifest xml file or whatever?
I tried switching activities without it and it crashed.
Then I added the other activity and it worked.
I ask because I hate the use of xml so I try to do everything programatically.
You need to learn to love XML :-) Yes, every activity needs to be declared in the manifest.
Actually android use xml everywhere, manifest, layout, menu, preference, string etc.So get used to it.
Related
I am building an Android app and are using the Parse SDK for Android.
Currently I am subscribing to channels with this in my main activity:
PushService.subscribe(this, "User_1_channel", MainActivity.class")
This works fine except for one thing. It opens up MainActivity and it gets put upon the other MainActivity in the stack which is very bad. I really want to remove the old activity before the new launches. I know I can do it with this but I have no idea where to put it since the Parse SDK handles everything.
launch.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
People say an alternative is to use a Custom broadcastreceiver. Problem with that approach is I have no idea how to subscribe to a channel without specifying an activity as the third parameter.
If you define the activity as SingleTask in your configuration file, it will indicate only that one activity will be used the Task.
android:launchMode="singleTask"
I have looked quite a few places but can't seem to find this specific solution. I am interested in creating a menu that will always be visible across every layout/view of the application. This menu would act much like the header/menu of a website that is fixed and always exists across all pages of the site. I assume I can simply create a menu and have it's visibility shown from initialization but I'm not sure if that's the best way. I don't want the user to have to click any other buttons to open the menu, I just want it fixed and constantly visible from the start of the app.
Thank you.
Any help is appreciated.
Fragments, they are a way to define parts of the user interface. They are similar to activities, they have their own lifecycle. They are also closely tied to the life cycle of their parent activity.
You can add them statically by declaring them in your xml manifest and in your layout file
-or-
you can add them dynamically in runtime by creating them as java objects and xml layout files and then add them using the FragmentManager class.
check out the Documentation on the android developer website
https://developer.android.com/guide/components/fragments.html
also, check out some tutorials on youtube, I like these ones especially:
https://www.youtube.com/watch?v=6GyGtCMoR_U&list=PLonJJ3BVjZW4lMlpHgL7UNQSGMERcDzHo
Good Luck!
I've recently setup eclipse and the android SDK on a new computer but I fear something has gone wrong when setting it up.
When I create a new android project with a blank activity two files I've never seen before appear:
fragment_main.xml
and
appcompat_v7_2
What are they and do I need to worry about them?
appcompat-v7 :
As stated in Android's Support Library Overview, it is considered good practice to include the support library by default because of the large diversity of devices and the fragmentation that exists between the different versions of Android (and thus, of the provided APIs)
Reference : Why does Eclipse automatically add appcompat v7 library support whenever I create a new project?
Fragment_main :
fragment_main.xml is the Layout for the fragment.
Refer this : Building a Dynamic UI with Fragments
hope this helps
The first, let read code in MainActivity!
You can see fragment_main is layout of one fragment in it.
when application running, fragment will be added to layout and show this layout.
Let read more about here for understanding about fragment. It is very important if you want to make android app.
I'm just getting started with Android dev, done a few tutorials, now I'm working on a simple app. On both the emulator and my phone (Android 4.0.3 emulator, Android 4.1.1 Atrix HD) apps are displaying in what I think is Holo Light. I'd rather have it be Holo Dark, but when I add the following line to the application block in the Android Manifest file: android:theme="#android:style/Theme.Holo" the app compiles fine but force closes as soon as I open it.
What am I doing wrong? I'm sure it's something really simple, but as I said I'm new to this. Thanks in advance, y'all!
If you want to use a theme for all the activities of your application then you need to use
<application android:theme="#style/CustomTheme">
in AndroidManifest.xml.If you want a theme applied to just one Activity in your application, then add the android:theme attribute to the activity tag instead.So need to know what type you use in your application.However see these things which will clear you more..
http://developer.android.com/guide/topics/ui/themes.html
http://www.androidengineer.com/2010/06/using-themes-in-android-applications.html
The simplest thing you can do and you should always do is to read logs why does it crash. The log will tell you the reason of you crash. Please post the reason including logs from Logcat and only then ask about fixes:)
i am iOS app developer. Now when i created an app on iOS i want to do the same on android. With java i was familiar just now need some time to remember.
i was looking at some tutorial how to do one or other things. But what i can't find is the basics how everything works. How classes is interacting with each other.
For example i want to create registration window with few buttons and alerts.
I want registration window to be called just once when app is installed and just that.
Should i create new java class and few layouts, one for View with buttons and other for Alerts ?
Or should i create other class for alerts if i need them in other flow of my app ?
And how i should call that window with registration from my main class, which is
extends Activity
Also if there are some developers who came this road from objective-c (iOS) to java (android). It would be nice for some share experience how they did that.
Thank you for any help :)
Very few of the concepts in iOS and Android are similar. On Android you have Activites, Intendts the Manifest. When you design your layout it should be resolution independent. You have a search, back and a menu button and variable hardware. All of this has no equivalent in iOS.
That said, I think you just have to read the basic concepts and the getting started guide no matter if you come from iOS or never have done mobile development before.
EDIT
To answer your concrete question. Take a look at the lifecycle of an Activity and Preferences. With this, you could do some action on the first start of your main Activity and store some flag in the preferences when it's done. On the next start you just test that preference and skip the logic.
You can create one activity (.java file) and one layout(.xml file with buttons and input boxes) , alerts could be toast notifications:
http://developer.android.com/guide/topics/ui/notifiers/toasts.html
All you require for this is a activity and a layout xml for that activity, this activity will be your main ie the entry point to your application, in that activity oncreate method you can check if it is registered or not by setting a flag or something which will direct to the next activity if its registered.
GOOD LUCK...
Just like your nibs in iPhone you create xml layouts in Android. And for view controllers here you make activity. One important thing is AndroidManifest.xml file, it contains all information of your app (like plist) plus all the activity information(Intent type and launcher methods).