Wednesday, December 23, 2009
1. Install and open the Apps Installer application from the "Android Market".
2. This opens a view showing *.apk application names in the sdcard root directory.(note, if no AppNames are listed you have no .apk files in the root directory of the SDCard)
3. Touch the app name to initiate installation of the app.
4. The app is now installed
How to Non-Market .Apk Application on your Google Android Phones
1. Download and install Google Android SDK. The tool you need is adb.exe.
2. Now type adb in a command shell will display all the options, adb.exe is SDK tool used to install applications and interface with the device.
3. Now Connect Your Android Phone to your computer using USB cable. You need to install Drivers for this. Download Android USB drivers from here. This driver is required for adb to interface with an android phone using USB cable.
4. Go to Android Settings/SD card & phone storage and disable Use for USB storage. You can enable it again later after you installed your third-party application.
5. Go to Settings/Application settings and enable Unknown sources.
6. Connect the G1 to your computer using the USB cable and install the driver you downloaded in step 3. After installing the driver you should see ADB Inteface in Windows Device Manager.
7. If you made it this far, download the APK file to a local folder on your computer, something like C:\MyAPKs will work fine and install it using ADB. The command would be adb install c:\myapks\ and that’s about it.
Anyway, the apk files refers to the Android Package files; and there are numbers of freeware you can try.
Tuesday, December 22, 2009
Sometimes you see references in your layout files like:
What's the difference?
.. I'm glad you asked ☺
@+id/foo means you are creating an id named foo in the namespace of your application.
You can refer to it using @id/foo.
@android:id/foo means you are referring to an id defined in the android namespace.
The '+' means to create the symbol if it doesn't already exist. You don't need it (and shouldn't use it) when referencing android: symbols, because those are already defined for you by the platform and you can't make your own in that namespace anyway.
This namespace is the namespace of the framework.
for example, you need to use @android:id/list because this the id the framework expects to find.. (the framework knows only about the ids in the android namespace.)
Sunday, December 20, 2009
For example, an activity might present a list of menu items users can choose from or it might display photographs along with their captions. A text messaging application might have one activity that shows a list of contacts to send messages to, a second activity to write the message to the chosen contact, and other activities to review old messages or change settings.
Though they work together to form a cohesive user interface, each activity is independent of the others. Each one is implemented as a subclass of the Activity base class.
An application might consist of just one activity or, like the text messaging application just mentioned, it may contain several. What the activities are, and how many there are depends, of course, on the application and its design.
Typically, one of the activities is marked as the first one that should be presented to the user when the application is launched. Moving from one activity to another is accomplished by having the current activity start the next one.
Each activity is given a default window to draw in. Typically, the window fills the screen, but it might be smaller than the screen and float on top of other windows.
An activity can also make use of additional windows — for example, a pop-up dialog that calls for a user response in the midst of the activity, or a window that presents users with vital information when they select a particular item on-screen.
The visual content of the window is provided by a hierarchy of views — objects derived from the base View class. Each view controls a particular rectangular space within the window. Parent views contain and organize the layout of their children. Leaf views (those at the bottom of the hierarchy) draw in the rectangles they control and respond to user actions directed at that space. Views are, therefore, where the activity's interaction with the user takes place.
For example, a view might display a small image and initiate an action when the user taps that image. Android has a number of ready-made views that you can use — including buttons, text fields, scroll bars, menu items, check boxes, and more.
A view hierarchy is placed within an activity's window by the Activity.setContentView() method. The content view is the View object at the root of the hierarchy.
When a new activity is started, it is placed on the top of the stack and becomes the running activity -- the previous activity always remains below it in the stack, and will not come to the foreground again until the new activity exits.
An activity has essentially four states:If an activity in the foreground of the screen (at the top of the stack), it is active or running.
If an activity has lost focus but is still visible (that is, a new non-full-sized or transparent activity has focus on top of your activity), it is paused.
A paused activity is completely alive (it maintains all state and member information and remains attached to the window manager), but can be killed by the system in extreme low memory situations.
If an activity is completely obscured by another activity, it is stopped.
It still retains all state and member information, however, it is no longer visible to the user so its window is hidden and it will often be killed by the system when memory is needed elsewhere.
There are three key loops you may be interested in monitoring within your activity:
If an activity is paused or stopped, the system can drop the activity from memory by either asking it to finish, or simply killing its process. When it is displayed again to the user, it must be completely restarted and restored to its previous state.
The entire lifetime of an activity happens between the first call to onCreate(Bundle) through to a single final call to onDestroy().
An activity will do all setup of "global" state in onCreate(), and release all remaining resources in onDestroy(). For example, if it has a thread running in the background to download data from the network, it may create that thread in onCreate() and then stop the thread in onDestroy().The visible lifetime of an activity happens between a call to onStart() until a corresponding call to onStop(). During this time the user can see the activity on-screen, though it may not be in the foreground and interacting with the user. Between these two methods you can maintain resources that are needed to show the activity to the user.
For example, you can register an IntentReceiver in onStart() to monitor for changes that impact your UI, and unregister it in onStop() when the user an no longer see what you are displaying. The onStart() and onStop() methods can be called multiple times, as the activity becomes visible and hidden to the user.
The foreground lifetime of an activity happens between a call to onResume() until a corresponding call to onPause(). During this time the activity is in front of all other activities and interacting with the user.
An activity can frequently go between the resumed and paused states -- for example when the device goes to sleep, when an activity result is delivered, when a new intent is delivered -- so the code in these methods should be fairly lightweight.
The entire lifecycle of an activity is defined by the following Activity methods. All of these are hooks that you can override to do appropriate work when the activity changes state. All activities will implement onCreate(Bundle) to do their initial setup; many will also implement onPause() to commit changes to data and otherwise prepare to stop interacting with the user.
You should always call up to your superclass when implementing these methods.
protected void onCreate(Bundle icicle);
Called when the activity is first created. This is where you should do all of your normal static set up: create views, bind data to lists, etc. This method also provides you with a Bundle containing the activity's previously frozen state, if there was one.
Always followed by
protected void onStart();Called when the activity is becoming visible to the user.
Followed by onResume() if the activity comes to the foreground, or onStop() if it becomes hidden.
protected void onRestart();
Called after your activity has been stopped, prior to it being started again. Always followed by
protected void onResume();
Called when the activity will start interacting with the user. At this point your activity is at the top of the activity stack, with user input going to it.
Always followed by onPause().
protected void onPause();
Called when the system is about to start resuming a previous activity. This is typically used to commit unsaved changes to persistent data, stop animations and other things that may be consuming CPU, etc. Implementations of this method must be very quick because the next activity will not be resumed until this method returns.
Followed by either onResume() if the activity returns back to the front, or onStop() if it becomes invisible to the user.
protected void onStop();
Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. This may happen either because a new activity is being started, an existing one is being brought in front of this one, or this one is being destroyed.
Followed by either onRestart() if this activity is coming back to interact with the user, or onDestroy() if this activity is going away.
protected void onDestroy();
The final call you receive before your activity is destroyed. This can happen either because the activity is finishing (someone called finish() on it, or because the system is temporarily destroying this instance of the activity to save space. You can distinguish between these two scenarios with the isFinishing() method.