【Android】Android实现计时与倒计时的几种方法 Timer与TimerTask

方法一
Timer与TimerTask（Java实现）
public class timerTask extends Activity{

private int recLen = 11;

private TextView txtView;

Timer timer = new Timer();

public void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.timertask);

txtView = (TextView)findViewById(R.id.txttime);

timer.schedule(task, 1000, 1000); // timeTask

}

TimerTask task = new TimerTask() {

@Override

public void run() {

runOnUiThread(new Runnable() { // UI thread

@Override

public void run() {

recLen--;

txtView.setText(""+recLen);

if(recLen < 0){

timer.cancel();

txtView.setVisibility(View.GONE);

}

}

});

}

};

}

方法二
TimerTask与Handler（不用Timer的改进型）
public class timerTask extends Activity{

private int recLen = 11;

private TextView txtView;

Timer timer = new Timer();

public void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.timertask);

txtView = (TextView)findViewById(R.id.txttime);

timer.schedule(task, 1000, 1000); // timeTask

}

final Handler handler = new Handler(){

@Override

public void handleMessage(Message msg){

switch (msg.what) {

case 1:

txtView.setText(""+recLen);

if(recLen < 0){

timer.cancel();

txtView.setVisibility(View.GONE);

}

}

}

};

TimerTask task = new TimerTask() {

@Override

public void run() {

recLen--;

Message message = new Message();

message.what = 1;

handler.sendMessage(message);

}

};

}

方法三

Handler与Message（不用TimerTask）
public class timerTask extends Activity{

private int recLen = 11;

private TextView txtView;

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.timertask);

txtView = (TextView)findViewById(R.id.txttime);

Message message = handler.obtainMessage(1); // Message

handler.sendMessageDelayed(message, 1000);

}

final Handler handler = new Handler(){

public void handleMessage(Message msg){ // handle message

switch (msg.what) {

case 1:

recLen--;

txtView.setText("" + recLen);

if(recLen > 0){

Message message = handler.obtainMessage(1);

handler.sendMessageDelayed(message, 1000); // send message

}else{

txtView.setVisibility(View.GONE);

}

}

super.handleMessage(msg);

}

};

}

方法四

Handler与Thread（不占用UI线程）
public class timerTask extends Activity{

private int recLen = 0;

private TextView txtView;

public void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.timertask);

txtView = (TextView)findViewById(R.id.txttime);

new Thread(new MyThread()).start(); // start thread

}

final Handler handler = new Handler(){ // handle

public void handleMessage(Message msg){

switch (msg.what) {

case 1:

recLen++;

txtView.setText("" + recLen);

}

super.handleMessage(msg);

}

};

public class MyThread implements Runnable{ // thread

@Override

public void run(){

while(true){

try{

Thread.sleep(1000); // sleep 1000ms

Message message = new Message();

message.what = 1;

handler.sendMessage(message);

}catch (Exception e) {

}

}

}

}

}

方法五

Handler与Runnable（最简单型）
public class timerTask extends Activity{

private int recLen = 0;

private TextView txtView;

public void onCreate(Bundle savedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.timertask);

txtView = (TextView)findViewById(R.id.txttime);

handler.postDelayed(runnable, 1000);

}

Handler handler = new Handler();

Runnable runnable = new Runnable() {

@Override

public void run() {

recLen++;

txtView.setText("" + recLen);

handler.postDelayed(this, 1000);

}

};

}