android program learning 1.1_20170414

1. install

      stp1: download JDK、 SDK 、 AndroidStudio

   JDK= java development kit  ( AS base on java environment)

   SDK=xxxx kit ( use for android program kit)

   AndroidStudio

     stp2: first install JDK

               second install AS

               Third with AS , SDK manager , choose SDK with option

      stp3: run!!

2. learn

      2.1. create project : ( android system construction the same as iOS ,  present layer,  application layer, resource layer ( with media, pics, content), basic layer ( with driver and sth.)

      2.2. activity :  every thing you view in android program is a activity.

      2.3. create and use view/ editText /  step: create layout file,  inside create main_activity.xml ( all the 

position and character can be put into here ) => create activity.java ( you can edit your java program to give some fuction or method to make the unit in xml to be “ fun!” => register all your add, especially the 

activity in your manifest.xml with “ “ ( some thing like that ) , after that you can running your program in simulator.

3.intent

           intent is a kind of method help you to transfer, shift between 2 or several activity.

           For example: If you want to make a register page. 

           U entered the username and the password. U push the button, and shift to the 2nd page.

           you want to keep the username & password from 1st page to 2nd page. you use intent.

4. About Java & class.

Java alway use “.xxx” (class) to act an action to an object. 

for example.          button.onClickListener()    => we give button object on action, to listen it if it is clicked.