To test our
applications we will need an Android Virtual Device (AVD). It is an Android
smartphone emulator, where Eclipse can install and launch our applications.
Let’s create it.
Launch Eclipse.
Go to Windows -> Android SDK and AVD
Manager (in newer versions - Android
AVD Manager)
Choose Virtual Devices on the left.
Click New.
In the Target list
Android platforms of different versions are presented. We've downloaded them in
previous lesson as the last step. Choose the right version and see the
information about it.
Return to Eclipse. Let’s choose platform 2.3.3 (API Level
10) from the list. And let’s give it the
corresponding name - AVD_233. Let’s also
specify the size of SD Card = 100 and HVGA Screen mode.
Press Create AVD and close AVD Manager
Finally, we can
create our first application and see how it works.
There multiple
versions of wizard for creating a project as Google constantly changes them!
Look for the one that suits you the best. They are sorted by date, the newest
first.
Version from
12/11/2012
In Eclipse go to File > New > Project
Choose the project type - Android > Android Application
Project, click Next
The window for
creating a project appears.
Let’s fill it in.
Let’s
begin with a Project Name - it
is the name of the project that will be displayed in the list of projects on
the left. As we will have many projects, I propose to think up a prefix for
names. It would be easier to return to older projects and they will be
structured nicely and conveniently.
The
prefix can be like this: P<lesson number(000)><lesson project
number(0)>. We will leave three numbers for the lesson number and one for
the project number. Let’s add some logical name to the prefix (OurFirstProject)
and we will get the name of our first project of the third lesson - P0031_OurFirstProject.
Application
name - it’s directly the name of the
application, which will be displayed in the device application list. We can
specify the project name without a prefix.
Package
name - Java term, explained in details here.
Shortly, it is a prefix for classes names of our application. I will be using ru.startandroid.develop.<application
name>
Minimum
Required SDK defines the minimum Android Version
within which the application will launch. Let’s choose the same as while
creating AVD - 2.3.3.
Compile
With defines the abilities of which Android
version will the application use. Specify 2.3.3 here.
Target
SDK defines the maximum Android version, on
which you have tested your application. It’s required for compatibility modes.
Specify also 2.3.3 here.
Do
not specify a Theme for
now, choose None
Click Next
From
ticks leave only
Create
Activity - immediately after the project
creation the Activity will be created, not to create it manually.
Create
Project in Workspace.
Project will be created and saved in the default workspace.
Click Next
Choose BlankActivity
Click Next
Make
sure here, that in field Activity Name MainActivity is
specified, and in field Layout Name enter main. Navigation Type - None.
Click Finish.
The project has
been created.
07/10/2012 Variant
In
Eclipse go to File > New > Project
Choose the project type - Android > Android Application
Project, click Next
The
window for creating a project appears.
Let’s
fill it in.
Let’s
begin with a Project Name - it
is the name of the project that will be displayed in the list of projects on
the left. As we will have many projects, I propose to think up a prefix for
names. It would be easier to return to older projects and they will be
structured nicely and conveniently.
The
prefix can be like this: P<lesson number(000)><lesson project
number(0)>. We will leave three numbers for the lesson number and one for
the project number. Let’s add some logical name to the prefix (OurFirstProject)
and we will get the name of our first project of the third lesson - P0031_OurFirstProject.
Application
name - it’s directly the name of the
application, which will be displayed in the device application list. We can
specify the project name without a prefix.
Package
name - Java term, explained in details here. Shortly, it is a
prefix for classes names of our application. I will be using ru.startandroid.develop.<application
name>
Build
SDK defines the abilities of which Android
version will the application use. Let’s choose the same as while creating AVD - 2.3.3.
Minimum
Required SDK defines the minimum Android Version
within which the application will launch. Let’s make it the same as Build SDK - 2.3.3.
From
ticks leave only Create Project in
Workspace.
The project will be created in the default workspace.
Click Next
The
window for Activity creation opens.
Choose
BlankActivity here and click Next.
Make
sure here, that in field Activity Name MainActivity is
specified, and in field Layout Name enter main. Do not touch
other fields.
Click Finish
The
project has been created.
Old variant
In Eclipse go to File > New > Project
Choose
the project type - Android > Android Application Project, click Next
The
window for creating a project appears. In newer versions this window is
splitted into three.
Let’s
fill it in.
Let’s
begin with a Project Name - it
is the name of the project that will be displayed in the list of projects on
the left. As we will have many projects, I propose to think up a prefix for
names. It would be easier to return to older projects and they will be
structured nicely and conveniently.
The
prefix can be like this: P<lesson number(000)><lesson project
number(0)>. We will leave three numbers for the lesson number and one for
the project number. Let’s add some logical name to the prefix (OurFirstProject)
and we will get the name of our first project of the third lesson - P0031_OurFirstProject.
Build
Target defines the abilities of which Android
version will the application use. Let’s choose the same as while creating AVD - 2.3.3.
Application
name - it’s directly the name of the
application, which will be displayed in the device application list. We can
specify the project name without a prefix.
Package
name - Java term, explained in details here.
Shortly, it is a prefix for classes names of our application. I will be using ru.startandroid.develop.<application
name>
Create
Activity - the name of Activity class
(application screen). Let’s specify MainActivity for
instance.
Leave
everything else as it is. Click Finish.
The
project has been created.
Screenshots below
may differ for different versions but not much.
On
the left our project appeared, let’s expand the project. We will look through
the most important and frequently used folders and files.
src - all our written source code will be situated in this folder
gen - filed generated by the environment that the application requires. You
better not touch anything here. (If there is no such folder - edit something in
the project and click Save button).
Android
2.3.3 - Android libraries required for the
application
assets and res - folders for resource files of different type
AndroidManifest.xml - manifest or configuration file of the application
We will use all
this later and it will be clear what it’s needed for.
Select the project
name on the left.
and
let’s run it - press CTRL + 11,
then
choose Android Application
click OK.
The
emulator will be launched, I advise not to touch or press anything, because
it’s laggy and unstable thing. Startup time is approximately one minute. Wait
until the following strings appear in Eclipse console.
The application is
installed on the emulator and is running. Unlock the emulator screen (if it is
locked) and observe our application.
You
can see the name of the application and the name of the Activity. We have just
created and launched our first application.
If
you didn’t manage to launch it and there is a message like this in Eclipse
console "emulator-5554 disconnected! Cancelling
'ru.startandroid.develop.OurFirstProject.MainAct activity launch'!" -
close the emulator and try again. If you didn’t manage to do it again - restart
Eclipse. If failed again - reboot. If it doesn’t work even now - delete the AVD
and create a new one. Finally it should work, even if not from the first try.
The
main thing here - after running the application (CTRL + F11) try to make as few
motions as you can on your computer. I have spotted a clear tendency - if you
switch different windows while emulator is starting, it launches with faults.
But if you sit and wait for a minute - everything would be fine. And
turn off all the other procedures like video rendering that load the
system.
