-3 the first step of activity

Long time don't write the tutorial, althought write too rotten.

Today is oN the how to delevop app first lesson. On the activity frist step.

Main content:

1. Boot Process of activity.

2, acivity and XML relationship.

3. Activity obtain control object.

1, on the boot process.

Android system frist go to load androidmainfest. XML, androidmainfest. XML contain frist run configure of activity, some system access jurisdiction. (for example access sdcard or net ). when loaded androidmainfest. XML Android system will go to run androidmainfest. XML
Contain frist activity. It will find this activity corresponding Java file. Run Into oncreate function. oncreate will find activity_main.xml.this time a activity almost OK. (The process will involve activty lifecycle .).

2, acivity and XML relationship

In general activity need a XML. xml full name is "Extensible Markup Language". Main function used to layout.

3. Activity obtain control object.

When a activity after call setcontendview () (this interface will Association XML), You can find control object. Find it later you can control it.

OK, today over.