2017.12.18 Android Development Process explained

Basic concepts of 1.JAVA threads:

Two ways to implement a thread:

(1) Inherit thread this class (the object represents a thread)

(2) Implement the Runnable interface (the object represents a thread body)

The life cycle of a thread:

Create

Generates a thread object;

Start method, ready;

Preemptive CPU operation;

The CPU is preempted by other threads or blocked and re-ready;

Execution completed;

A state of death that cannot be resurrected after death;

Android: Child threads in principle do not allow UI components to be modified, only the main thread can modify the UI components

2. Interface settings and component introduction:

    Private button button;     Private TextView TextView;    @Override    protectedvoid  onCreate (Bundle savedinstancestate) {        super.oncreate (savedinstancestate);        Setcontentview (r.layout.activity_main);        TextView=(TextView) Findviewbyid (R.id.textview);        Button=(Button) Findviewbyid (R.id.button);        Button.setonclicklistener (new  Buttonlistener ());    }

3. Creating and modifying sub-threads View:

    classButtonlistener implements view.onclicklistener{@Override Public voidOnClick (view view) {MyThread T=NewMyThread ();//generating child threads in the main threadT.start (); }    }    classMyThread extends thread{@Override Public voidrun () {//Super.run ();            Try{CurrentThread (). Sleep ( -); } Catch(interruptedexception e) {e.printstacktrace (); } textview.settext ("This one is a modification from a sub-thread"); }    }

4. Modify the view in the main thread:

2017.12.18 Android Development Process explained