Handler common methods in Android

Package com. example. testhandler;
Import android. OS. Bundle;
Import android. OS. Handler;
Import android. OS. Message;
Import android. app. Activity;
// Handler common methods:
// 1 post ()
// 2 postDelayed ()
// 3 sendMessage ()
// 4 handleMessage ()
Public class MainActivity extends Activity {
Runnable updateRunnable;
Private final int CANCEL_RUNNABLE = 99;
@ Override
Public void onCreate (Bundle savedInstanceState ){
Super. onCreate (savedInstanceState );
SetContentView (R. layout. activity_main );
Final Handler handler = new Handler (){
@ Override
Public void handleMessage (Message msg ){
Super. handleMessage (msg );
// The first Handler type is as follows: handle the Message according to what is different.
If (msg. what = 1 ){
System. out. println ("Receive message ");
}
// The first type is Handler: handle the Message according to what it is.

// Handler: handler. postDelayed (Runnable, delayMillis)
If (msg. what = CANCEL_RUNNABLE ){
System. out. println ("current message msg. what =" + msg. what );
// Cancel Runnable execution
RemoveCallbacks (updateRunnable );
}
// The second type is Handler. postDelayed (Runnable, delayMillis)
}
};

//////////////////////////////////////// //////////////////////////////////////// /////////////

// The following is the first type of Handler: Send a Message
New Thread (){
@ Override
Public void run (){
Message message1 = new Message ();
Message1.what = 1;
Message1.obj = new Object ();
// Handle sends a Message object
// To facilitate the test to annotate the sentence
// Handler. sendMessage (message1 );
Super. run ();
}
};
// The preceding example is Handler. The first example is to send a Message.

// Handler: handler. postDelayed (Runnable, delayMillis)
// The Runnable will be delayed for a certain period of execution in the thread bound to the Handler.
UpdateRunnable = new Runnable (){
Public void run (){
For (int I = 5; I <15; I ++ ){
System. out. println ("I =" + I) in Runnable );
}
}
};
// Handle sends out a Runnable object
// Comments the following two sentences to facilitate the test
// Handler. post (updateRunnable) cannot be used );
// Handler. postDelayed (updateRunnable, 5000) should be used );
// Then a message is sent immediately, so that it can be in handleMessage
// Call the removeCallbacks () method
Handler. postDelayed (updateRunnable, 1000 );
Handler. sendEmptyMessage (CANCEL_RUNNABLE );
// The second type is Handler. postDelayed (Runnable, delayMillis)


// Handler. post (Runnable)
// The issued Runnable will be executed by a neutral horse in the thread bound to the Handler.
// Comments the following code to facilitate the test
// Handler. post (updateRunnable );
// The third type is Handler. post (Runnable)
}

 

}