Android中的倒计时的功能（也可以直接使用CountDownTimer这个类直接实现，相关此Demo可查看我的博客），参考了网上写的很好的一个倒计时Demo：

下面提供下代码，和大家一起分享一下：

MainActivity：

package com.example.mytime;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {

	Button startButton;
	EditText minuteText;
	EditText secondText;
	int minute;
	int second;
	
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.main);

		startButton = (Button) findViewById(R.id.button_start);
		minuteText = (EditText)findViewById(R.id.minute);
		secondText = (EditText)findViewById(R.id.second);
		
		startButton.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				if (!minuteText.getText().toString().equals("")) {
					minute = Integer.parseInt(minuteText.getText().toString());
				}
				if (!secondText.getText().toString().equals("")) {
					second = Integer.parseInt(secondText.getText().toString());
				}
				if (minute != 0 || second != 0) {
					
					ArrayList<Integer> list = new ArrayList<Integer>();
					list.add(minute);
					list.add(second);
					
					Intent intent = new Intent();
					intent.setAction("com.example.mytime.StartActivity");
					
					intent.putIntegerArrayListExtra("times", list);
					startActivity(intent);
				}
			}
		});
	}
	
	@Override
	protected void onResume() {
		minute = 0;
		second = 0;
		super.onResume();
	}
}

package com.example.mytime;

import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Window;
import android.widget.TextView;

public class StartActivity extends Activity{

	static int minute = -1;
	static int second = -1;
	final static String tag = "tag";
	TextView timeView;
	Timer timer;
	TimerTask  timerTask;
	Handler handler = new Handler(){
		public void handleMessage(Message msg) {
			System.out.println("handle!");
			if (minute == 0) {
				if (second == 0) {
					timeView.setText("Time out !");
					if (timer != null) {
						timer.cancel();
						timer = null;
					}
					if (timerTask != null) {
						timerTask = null;
					}
				}else {
					second--;
					String minutes = String.valueOf(minute);
					String minute = minutes;
					minute = "";
					if (second >= 10) {
						minutes = String.valueOf(minute);
						minute = minutes;
						minute = "";
						timeView.setText(minute + second);/*"0"+minute + ":" + */
					}else {
						timeView.setText(minute + "0" + second);/*"0"+minute + ":0" + */
					}
				}
			}else {
				if (second == 0) {
					second =59;
					minute--;
					if (minute >= 10) {
						timeView.setText(minute + ":" + second);
					}else {
						timeView.setText("0"+minute + ":" + second);
					}
				}else {
					second--;
					if (second >= 10) {
						if (minute >= 10) {
							timeView.setText(minute + ":" + second);
						}else {
							timeView.setText("0"+minute + ":" + second);
						}
					}else {
						if (minute >= 10) {
							timeView.setText(minute + ":0" + second);
						}else {
							timeView.setText("0"+minute + ":0" + second);
						}
					}
				}
			}
		};
	};
	
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		requestWindowFeature(Window.FEATURE_NO_TITLE);
		super.onCreate(savedInstanceState);
		setContentView(R.layout.start);
		timeView = (TextView)findViewById(R.id.myTime);
		
		if (minute == -1 && second == -1) {
			Intent intent = getIntent();
			ArrayList<Integer> times = intent.getIntegerArrayListExtra("times");
			minute = times.get(0);
			second = times.get(1);
		}
		
		timeView.setText(minute + ":" + second);
		
		timerTask = new TimerTask() {
			
			@Override
			public void run() {
				Message msg = new Message();
				msg.what = 0;
				handler.sendMessage(msg);
			}
		};
		
		timer = new Timer();
		timer.schedule(timerTask,0,1000);
		
	}
	
	@Override
	protected void onDestroy() {
		if (timer != null) {
			timer.cancel();
			timer = null;
		}
		if (timerTask != null) {
			timerTask = null;
		}
		minute = -1;
		second = -1;
		super.onDestroy();
	}
}

Android倒计时功能的实现