Support Multible screen in Android

Supporting Multiple Screen in Android:



i developed one android application few days before..but the application screen is fit in only larger mobile ..i run that application in small screen the pixel is  not good ..so i use developer.android.com to learn how to develop on android .apk application it can support all screen size without damaging the pixel or4 density of the screen 


the things we have to remember when we are developing mobile application there is different screen size mobile are available in market ..so before developing application to decide which are devices your application is support ..


in android  screen support:

android groups all mobile screen size in to four groups


Screen Size :
1 small
2 medium
3 large
4 extra large

Screen Density

low density(ldpi) -120 dpi
medium density (mdpi) -160dpi
high density(hdpi) -240dpi
x high density(xhdpi) -320dpi

Resolution 
the total number of pixcel in the screen ..in android multable screen does not support i resolution .it consider only screen size and screen density

 

Density-independent pixel (dp)

A virtual pixel unit that you should use when defining UI layout, to express layout dimensions or position in a density-independent way.

do you want find the pixel for equivalent  decimal(dp) 

 
px = dp * (dpi / 160)

the inches is define foe screen size 1inches =2.54


each design requires minimum amount of space in memory.. the minimum size of screen is given by the dp value.. if you want to change this in pixel use the above formula

• xlarge screens are at least  960dp x 720dp
• large screens are at least    640dp x 480dp 
• normal screens are at least   470dp x 320dp 
•   small screens are at least   426dp x 320dp

for archiving this multiple  screen  application support you can provide alter native  layout for different screen size and alternative bitmap images for different density..

 


Diffrent layout for diffrent screen size

res/layout/my_layout.xml // layout for normal screen size ("default") 

res/layout-small/my_layout.xml // layout for small screen size 

res/layout-large/my_layout.xml // layout for large screen size

  res/layout-xlarge/my_layout.xml // layout for extra large screen size

  res/layout-xlarge-land/my_layout.xml

to store bitmap image i diffrent density ..

1.   res/drawable-mdpi/my_icon.png // bitmap for medium density 

   2 res/drawable-hdpi/my_icon.png // bitmap for high density 

   3 res/drawable-xhdpi/my_icon.png // bitmap for extra high density

 

after creating the above files.. your application is ready to run in a different  screen size device .at run time of your application it loads current configuration loads the associate resources for running the application ..

 

Styles and theme in Android :


it same like CSS when applying styles in our web application .in android styles and theme are used to apply colors layout styles in to your activity..
it allow get content from design..

Using the style in Your View and ViewGroup Activity in Android Layout


<TextView
style="@style/Mono"
android:Text="@string/hello" >

Define the style in res/Values inside that strings.xml file .the file is applied at compile time of your application..

<resources> <style name="MONO" parent="@android:style/TextAppearance.Medium"> 

 <item name="android:layout_width">fill_parent</item> 

 <item name="android:layout_height">wrap_content</item>  

<item name="android:textColor">#000F00</item>

  <item name="android:typeface">monospace</item> </style>

  </resources>

  this is only for single view you also apply them for entire Activity and Aplication.

for application you aply your theme

<application android:theme="@style/YourTheme"> 

 

apply theme for your Activity 

<activity Android:theme="@style/theme">

 apply parent theme to your theme in Manifest.xml file 

for more information about applying theme and activity in your Application refere the following link

• Android Styles
•  Android Themes

after i learning this my application is support all screen size of android device...