Develop Reference

how do i print receipt(which is activity layout) from my android app

I have to print some receipt using my own android application. Is it possible in android? Do I have to use third party API's? I am asking the question just because there is no proper solution,or documentation for print.
If there is some documentation or any solution, please provide me link. I need to know about the possibilities of printing document and receipt in android. I also want to know which printer would be the best?

Yes ..you can print document use Bluetooth printer..I think following link will helpful to move your project next level.
Best Printer for Android Mobile

Print text data using blue tooth supported printer

I want to use printer to print data from our android application, can any one suggest me good and simple technique to print the text data on paper?
Thanks in Advance.

Hi You can use below android documentation to achieve this task but make sure that your printer is Moperia cerified(http://mopria.org/)
https://developer.android.com/training/printing/custom-docs.html
https://developer.android.com/training/printing/index.html
Thanks

Hot to get data from wearable

I don't know how to get those data from smartwatch to my android smartphone. Anyone ever develop apps like this? please help me or you can tell me the reference for me to develop this apps. Please help, Thank you

Take reference of the application SensorDashboard.
I found it very useful to understand and implement sensor related operations on smart-watch and get it on phone ultimately.

Did you try this Sony Smartwatch link or the link for developing apps for Android Wearables? If you're really in Indonesia as your profile says you could look here too.

How to connect a mobile and a printer via WIFI to print a text file in android?

Can anyone tell me how to connect a mobile and a printer via Wifi to print a text file in android?That is,if i press the print button from the android application,the printer has to print that corresponding file.As per my knowledge i have searched for it in Google, but i couldn't find any good samples to do it.Has anyone have at-least one sample android program to do this, it will be better to clear my chaos.
Suggestions please.

ther is no api provided by google (<19, thanks to #KaranJ), so third part solutions have to be done, eg:
http://www.printershare.com/help-android-integration.sdf
https://developers.google.com/cloud-print/docs/android
a standalone solution would be very difficult! :/
you could use an alert dialog builder, to guide the user to the google playstore, for installing something like printshare or google cloud print.
EDIT
also the content should be laid out to be ready for printing, more here:
http://developer.android.com/reference/android/print/PrintManager.html
http://developer.android.com/training/printing/custom-docs.html

Wireless printing api are only available in api level 19, so I think you should go with the answer of #thenobol

NFC Read Tag with Android API

I am still learning the Android API.
Could someone give me some guidelines for using the Android API to enable NFC read tags?
What are the major items that have to happen in order to read the content of message?
What is the sequence of things that are supposed to happen? Does someone has a few lines of sample code?
For instance:
How to read the intent filter: do I use "PendingIntent"?
Does the app need to be able to handle exception? If yes, how.
How to use "NfcAdapter".

This is what you need to get started. Read the basics section and you should be off :)

Check out this NFC workshop series. this will help you.