Difference between px, dp, dip and sp in Android?

• px is one pixel.
• sp is scale-independent pixels.
• dip is Density-independent pixels.

You would use

• sp for font sizes
• dip for everything else.
  dip==dp

From Android Developers center:

px
Pixels - corresponds to actual pixels on the screen.
in
Inches - based on the physical size of the screen.
1 Inch = 2.54 centimeters
mm
Millimeters - based on the physical size of the screen.
pt (it depends upon physical size of the screen) Points - 1/72 of an inch based on the physical size of the screen.

This will help you for more understanding.

dp
Density-independent Pixels - an abstract unit that is based on the physical density of the screen. These units are relative to a 160 dpi screen, so one dp is one pixel on a 160 dpi screen. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion. Note: The compiler accepts both "dip" and "dp", though "dp" is more consistent with "sp".
sp
Scale-independent Pixels - this is like the dp unit, but it is also scaled by the user's font size preference. It is recommend you use this unit when specifying font sizes, so they will be adjusted for both the screen density and user's preference.

Show icons in Action Bar

Try this code

1) Using android default action bar

 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
 <item android:id="@+id/action_search"
      android:icon="@drawable/ic_action_search"
      android:title="@string/action_search"
      android:showAsAction="always"       
  />

</menu>

2) If using supported action bar

 <menu xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:yourapp="http://schemas.android.com/apk/res-auto" >
  <item android:id="@+id/action_search"
      android:icon="@drawable/ic_action_search"
      android:title="@string/action_search"
      yourapp:showAsAction="always"    
  />
 </menu>

for more info u can refer to this link
http://developer.android.com/guide/topics/ui/actionbar.html

Display response from http in next activity

Show response in next activity can be done in following ways

Solution 1 response comes in string so pass whole response to next activity by using

         intent.putExtras("Key",response);

Solution 2 make a singleton class of getter setter , by using this class u can set and get values throughout our application .
like this

 step 1

public class SingleObject {

 //create an object of SingleObject
 private static SingleObject instance = new SingleObject();

 private String name;
 private String age;

 //make the constructor private so that this class cannot be
 //instantiated
   private SingleObject(){}

 //Get the only object available
 public static SingleObject getInstance(){
  return instance;
 }

  // here u can declare getter setter


public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getAge() {
    return age;
}

public void setAge(String age) {
    this.age = age;
}

}

step 2  use it in first activity like this
    
     Singleton tmp = Singleton.getInstance( ); tmp.setName("");

step 3 and in next activity like this

    Singleton tmp = Singleton.getInstance( ); String name = tmp.getName;

Solution 3 : Make a static Arraylist of hashmap and use it in any activity

or there may be more solutions .....

enjoy coding

Change Action bar title Font Style android

CHANGE ACTION BAR TITLE FONT STYLE

Step 1)

get the resource ID of android title

int actionBarTitle = Resources.getSystem().getIdentifier("action_bar_title", "id", "android");

Step 2)

Now
make object of text view and typecast the ID aquired above to textview object

TextView actionBarTitleView = (TextView) getWindow().findViewById(actionBarTitle);

Step 3)

make the folder  named fonts in assets and copy  any fontstyle.ttf file in that folder


Typeface forte = Typeface.createFromAsset(getAssets(), "fonts/FORTE.TTF");

Step 4)
 Give changes according to your need to the text view

if(actionBarTitleView != null){
            actionBarTitleView.setTypeface(forte);
            actionBarTitleView.setTextSize(25);

        }
 
Step 5)

Now set title for Action bar

getActionBar().setTitle("SAMPLE");

it will set the tile with the fontstyle u specified with textview object

COMPLETE CODE
copy and paste

    int actionBarTitle = Resources.getSystem().getIdentifier("action_bar_title", "id", "android");
        TextView actionBarTitleView = (TextView) getWindow().findViewById(actionBarTitle);
        Typeface forte = Typeface.createFromAsset(getAssets(), "fonts/FORTE.TTF");
        if(actionBarTitleView != null){
            actionBarTitleView.setTypeface(forte);
            actionBarTitleView.setTextSize(25);
        }
       
       
       getActionBar().setTitle("SAMPLE");


NOW run your app and see the changes

Top 5 E-books for Android Developers

Top 5 books For Android Developers

 1) Hello, Android (English)

 Authored by Ed Burnette, “Hello, Android” is a great tool to help you get started with your first Android application. Introducing the basics of Android development, you slowly start getting more conversant with this mobile platform.
The third edition presents examples of testing compatibility with the different features and versions of the Android OS.
Gradually, this book teaches you to develop more features into your app, such as audio and video support, graphics and so on. It also gives you a tutorial on publishing your app to the Android Market.
This book is definitely worth a look for those who are looking for a practical tutorial in Android development.

 2) Sams Teach Yourself Android Application Development in 24 Hours (English)

Learn Android app development in 24 sessions, devoting one hour for each session. This book teaches you common tasks in Android development and to design, develop, test and publish your app to the Android Market.
The “Quizzes and Exercises” section at the end of each chapter test your grasp on the subject. “By the Way” notes give you related information. The “Did You Know?” section offers you helpful tips along the way. The “Watch Out!” section helps you prevent common pitfalls.
You learn to work with Java, Android SDK, Eclipse and so on and to use Android’s built-in features to create user-friendly UIs for your Android app. Gradually, you also learn to integrate network, social and location-based features in your Android app.

3) Android Application Development All-in-one for Dummies (English)

 This book, as the name suggests, is for those who have never attempted coding for Android before. Authored by Donn Felker, it explains how to download the Android SDK and work with Eclipse in order to get your Android app running. Beginning with the very basics of Android development, it also teaches you how to price your app and submit it to the Android Market.
You start with working with the basic app development process, learning to work with Android’s features to design easy-to-use UIs. It teaches you about working with classes, databases, multiple screens, debugging, creating home screen widgets and so on. You also learn to use built-in Android conveniences to your advantage

4) Beginning Android Tablet Development

This book shows you how to get started with Android tablet programming, without prior experience. Educating you from the ground up, this tutorial enables you develop your own Android tablet apps, starting with Android 3.0 Honeycomb onwards.
This book teaches you to work with 2D programming, slowly moving on to a 3D
touchscreen interface with the Honeycomb SDK. Whether it is to develop a location-based app or create your first 2D or 3D Android game, this book takes you through a nice journey on basic Andriod tablet development.
This book also teaches you to move away from Java and explore other languages while working with the Android OS.

5) Professional Android 2 Application Development Book Review

This book teaches you to leverage all the features available in Android 2.0 onwards. The only condition here is that you should already know about the basics of Java programming, Eclipse and the like.
Starting with working on the basic Hello World examples, you slowly learn to develop more advanced apps with layouts, menus, UIs and other features. The ensuing chapters teach you to handle databases, location-based apps, widgets, network and radio connectivity features and such.
You are then introduced to create more sophisticated surface views, animations and other interactive controls, thereby enabling you to gain more confidence with Android app development.





Enjoy Coding ....!!!!!!!!!!!!!!!!

ANDROID IMAGE CAPTURE FROM CAMERA AND DISPLAY TO

ANDROID IMAGE CAPTURE FROM CAMERA AND DISPLAY TO <IMAGEVIEW />
 

STEP1

CREATE activity_main.xml with following code

 <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="ImageFromCameraAndGallary" />
   
    <ImageView
        android:id="@+id/imgview"
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:layout_below="@+id/text"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        />
    <Button
        android:id="@+id/buttonClickImage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/imgview"
        android:text="Click Image"
        />

STEP2

CREATE MainActivity.java with following code

public class MainActivity extends Activity {
    private static final int CAMERA_REQUEST = 1888;
    public ImageView image;
    public Button button;
   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        image = (ImageView) findViewById(R.id.imgview);
        button = (Button) findViewById(R.id.buttonClickImage);
       
        button.setOnClickListener(new OnClickListener() {
          
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent camaeraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                startActivityForResult(camaeraIntent, CAMERA_REQUEST);
              
            }
        });
    }
   
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
            Bitmap photo = (Bitmap) data.getExtras().get("data");
            image.setImageBitmap(photo);
        } 
    }
}






STEP3

FINALLY give premission to use camera to our android app by giving permission in android.manifest.xml



<uses-feature android:name="android.hardware.camera"></uses-feature>








IT works  fine...