倒计时实现方案总结 Timer Handler

利用Timer实现倒计时

@BindView(R.id.send) Button send;//发送验证码
private int time = 60;//倒计时
private Timer timer;
private Handler handler = new Handler() {
	public void handleMessage(android.os.Message msg) {
		switch (msg.what) {
			case 1:
				send.setText(time + "S");
				break;
			
			case 2:
				send.setEnabled(true);
				send.setText("重新发送");
				break;
		}
	}
};
@OnClick({R.id.send, R.id.next})
public void onClickIv(View v) {
	switch (v.getId()) {
		case R.id.send:
				send.setEnabled(false);
				getVerificationCode();
			break;
	}
}
//定时器
private void setTimer() {
	timer = new Timer();
	TimerTask task = new TimerTask() {
		@Override
		public void run() {
			time--;
			if (time > 0) handler.sendEmptyMessage(1);
			else {
				handler.sendEmptyMessage(2);
				destoryTimer();
			}
		}
	};
	timer.schedule(task, 0, 1000);
}
private void destoryTimer() {
	if (timer != null) {
		timer.cancel();
		timer = null;
	}
}
@Override
protected void onDestroy() {
	super.onDestroy();
	destoryTimer();
}

当然也可以不用Handler而用其他更精简的API，比如：

TimerTask task = new TimerTask() {
	@Override
	public void run() {
		runOnUiThread(new Runnable() {
			@Override
			public void run() {
				time--;
				if (time > 0) send.setText(time + "S");
				else {
					send.setEnabled(true);
					send.setText("重新发送");
					destoryTimer();
				}
			}
		});
	}
};

利用Handler实现倒计时

handler.sendMessageDelayed(handler.obtainMessage(1), 1000);

final Handler handler = new Handler() {
	public void handleMessage(Message msg) {
		switch (msg.what) {
		case 1:
			time--;
			if (time > 0) {
				send.setText(time + "S");
				handler.sendMessageDelayed(handler.obtainMessage(1), 1000);
			} else {
				send.setEnabled(true);
				send.setText("重新发送");
			}
		}
	}
};

类似的实现方式

Handler handler = new Handler(); 
handler.postDelayed(runnable, 1000);

Runnable runnable = new Runnable() {
	@Override
	public void run() {
		time--;
		if (time > 0) {
			send.setText(time + "S");
			handler.postDelayed(this, 1000);
		} else {
			send.setEnabled(true);
			send.setText("重新发送");
		}
	}
};

利用CountDownTimer实现

CountDownTimer timer = new CountDownTimer(60000, 1000) {
	@Override
	public void onTick(long millisUntilFinished) {
	    send.setText(time + "S");
	}
	@Override
	public void onFinish() {
		send.setEnabled(true);
		send.setText("重新发送");
	}
};

GitHub上星星最多的倒计时控件

https://github.com/iwgang/CountdownView 

CountdownView：Android倒计时控件，使用Canvas绘制，支持多种样式

compile 'com.github.iwgang:countdownview:2.1.3'

XML

<cn.iwgang.countdownview.CountdownView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

基本使用

CountdownView mCountdownView = (CountdownView)findViewById(R.id.countdownView);
mCountdownView.start(995550000); // 毫秒

// 或者自己编写倒计时逻辑，然后调用updateShow来更新UI
for (int time=0; time<1000; time++) {
    mCountdownView.updateShow(time);
}

动态显示设置, 支持所有xml中的配置项来使用java代码设置

mCountdownView.dynamicShow(DynamicConfig dynamicConfig)

倒计时结束后回调

mCountdownView.setOnCountdownEndListener(OnCountdownEndListener);

指定间隔时间回调

mCountdownView.setOnCountdownIntervalListener(long, OnCountdownIntervalListener);

RecyclerView中倒计时方案1【最简单】

这种方案在数据量特别小（即List的size()特别小），且刷新item及计算倒计时耗费的时间特别短时适用，否则，将会产生巨大的时间延迟。

1、更改数据源（即重新设置倒计时剩余时间）

//定时器，用于刷新GridView的数据源
private void setQryTimer() {
	cancelQryTimer();
	qryTimer = new Timer();
	qryTimer.schedule(new TimerTask() {
		@Override
		public void run() {
			runOnUiThread(new Runnable() {
				public void run() {
					if (fixRpList != null && fixRpList.size() > 0) {
						for (FixRpBean item : fixRpList) {
							if (item.diff_time >= 0) item.diff_time = item.diff_time - 1000L;
						}
						if (fixRpDialog != null) fixRpDialog.upDate(fixRpList);
					}
				}
			});
		}
	}, 0, 1000);
}

2、刷新item（建议使用RecyclerView的局部刷新功能）

public void upDate(List<FixRpBean> redPacketList) {
	list.clear();
	list.addAll(redPacketList);
	mRecyclerView.getAdapter().notifyDataSetChanged();//建议使用RecyclerView的局部刷新功能
}

RecyclerView中倒计时方案2【推荐】

核心思想为：利用System.currentTimeMillis()帮我们计算倒计时。

并且：在onViewAttachedToWindow时重新开始倒计时，在onViewDetachedFromWindow时关闭倒计时。

/**
 * 复用 本地的计时器 —— System.currentTimeMillis(), 不必自行计时
 */
public class RecyclerViewActivity extends Activity {
	private List<ItemInfo> mDataList;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_recyclerview);
		
		initData();
		
		RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rv);
		recyclerView.setAdapter(new MyAdapter(this, mDataList));
		recyclerView.setLayoutManager(new LinearLayoutManager(this));
		recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
		recyclerView.setItemAnimator(new DefaultItemAnimator());
	}
	
	private void initData() {
		mDataList = new ArrayList<>();
		for (int i = 1; i < 20; i++) {
			mDataList.add(new ItemInfo(i * 20 * 1000));
		}
		// 校对倒计时
		long curTime = System.currentTimeMillis();
		for (ItemInfo itemInfo : mDataList) {
			itemInfo.endTime = curTime + itemInfo.countdown;
		}
	}
	
	static class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
		private Context mContext;
		private List<ItemInfo> mDatas;
		
		public MyAdapter(Context context, List<ItemInfo> datas) {
			this.mContext = context;
			this.mDatas = datas;
		}
		
		@Override
		public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
			return new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false));
		}
		
		@Override
		public void onBindViewHolder(MyViewHolder holder, int position) {
			holder.bindData(mDatas.get(holder.getAdapterPosition()));
		}
		
		@Override
		public int getItemCount() {
			return mDatas.size();
		}
		
		//**************************************************关键代码****************************************
		@Override
		public void onViewAttachedToWindow(MyViewHolder holder) {
			super.onViewAttachedToWindow(holder);//父类中为空代码
			holder.refreshTime(mDatas.get(holder.getAdapterPosition()).endTime - System.currentTimeMillis());
		}
		
		@Override
		public void onViewDetachedFromWindow(MyViewHolder holder) {
			super.onViewDetachedFromWindow(holder);
			holder.countdownView.stop();
		}
		//**************************************************关键代码****************************************
	}
	
	static class MyViewHolder extends RecyclerView.ViewHolder {
		public CountdownView countdownView;
		
		public MyViewHolder(View itemView) {
			super(itemView);
			countdownView = (CountdownView) itemView.findViewById(R.id.countdownView);
		}
		
		public void bindData(ItemInfo itemInfo) {
			refreshTime(itemInfo.endTime - System.currentTimeMillis());
		}
		
		public void refreshTime(long leftTime) {
			if (leftTime > 0) {
				countdownView.start(leftTime);
			} else {
				countdownView.stop();//停止计时器，mCustomCountDownTimer.stop();
				countdownView.allShowZero();//所有计时清零，即mCountdown.setTimes(0, 0, 0, 0, 0);
			}
		}
	}
	
	static class ItemInfo {
		public long countdown;
		/*
		   根据服务器返回的countdown换算成手机对应的开奖时间 (毫秒)
		   [正常情况最好由服务器返回countdown字段，然后客户端再校对成该手机对应的时间，不然误差很大]
		 */
		public long endTime;
		
		public ItemInfo(long countdown) {
			this.countdown = countdown;
		}
	}
}

RecyclerView中倒计时方案3【最麻烦】

这种方案为：自己维护倒计时，再调用countdownView.updateShow来刷新显示

并且：在onResume时开启倒计时，在onPause及onDestroy时关闭倒计时。

个人极其不推荐这种方案，既麻烦又低效。

/*
   自己维护倒计时任何，再调用countdownView.updateShow来刷新显示
 */
public class RecyclerViewActivity2 extends AppCompatActivity {
	private MyAdapter mMyAdapter;
	private List<ItemInfo> mDataList;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_recyclerview);
		
		initData();
		
		RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rv);
		mMyAdapter = new RecyclerViewActivity2.MyAdapter(this, mDataList);
		recyclerView.setAdapter(mMyAdapter);
		recyclerView.setLayoutManager(new LinearLayoutManager(this));
		recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL));
		recyclerView.setItemAnimator(new DefaultItemAnimator());
	}
	
	private void initData() {
		mDataList = new ArrayList<>();
		for (int i = 1; i < 20; i++) {
			mDataList.add(new ItemInfo(1000 + i, "RecyclerView_测试标题_" + i, i * 20 * 1000));
		}
		// 校对倒计时
		long curTime = System.currentTimeMillis();
		for (ItemInfo itemInfo : mDataList) {
			itemInfo.setEndTime(curTime + itemInfo.getCountdown());
		}
	}
	
	@Override
	protected void onResume() {
		super.onResume();
		if (null != mMyAdapter) mMyAdapter.startRefreshTime();
	}
	
	@Override
	protected void onPause() {
		super.onPause();
		if (null != mMyAdapter) mMyAdapter.cancelRefreshTime();
	}
	
	@Override
	public void onDestroy() {
		super.onDestroy();
		if (null != mMyAdapter) mMyAdapter.cancelRefreshTime();
	}
	
	static class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
		private Context mContext;
		private List<ItemInfo> mDatas;
		private final SparseArray<MyViewHolder> mCountdownVHList;
		private Handler mHandler = new Handler();
		private Timer mTimer;
		private boolean isCancel = true;
		
		public MyAdapter(Context context, List<ItemInfo> datas) {
			this.mContext = context;
			this.mDatas = datas;
			mCountdownVHList = new SparseArray<>();
			startRefreshTime();
		}
		
		public void startRefreshTime() {
			if (!isCancel) return;
			if (null != mTimer) mTimer.cancel();
			
			isCancel = false;
			mTimer = new Timer();
			mTimer.schedule(new TimerTask() {
				@Override
				public void run() {
					mHandler.post(mRefreshTimeRunnable);
				}
			}, 0, 10);
		}
		
		public void cancelRefreshTime() {
			isCancel = true;
			if (null != mTimer) {
				mTimer.cancel();
			}
			mHandler.removeCallbacks(mRefreshTimeRunnable);
		}
		
		@Override
		public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
			return new MyViewHolder(LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false));
		}
		
		@Override
		public void onBindViewHolder(MyViewHolder holder, int position) {
			ItemInfo curItemInfo = mDatas.get(position);
			holder.bindData(curItemInfo);
			
			// 处理倒计时
			if (curItemInfo.getCountdown() > 0) {
				synchronized (mCountdownVHList) {
					mCountdownVHList.put(curItemInfo.getId(), holder);
				}
			}
		}
		
		@Override
		public int getItemCount() {
			return mDatas.size();
		}
		
		@Override
		public void onViewRecycled(MyViewHolder holder) {
			super.onViewRecycled(holder);
			
			ItemInfo curAnnounceGoodsInfo = holder.getBean();
			if (null != curAnnounceGoodsInfo && curAnnounceGoodsInfo.getCountdown() > 0) {
				mCountdownVHList.remove(curAnnounceGoodsInfo.getId());
			}
		}
		
		private Runnable mRefreshTimeRunnable = new Runnable() {
			@Override
			public void run() {
				if (mCountdownVHList.size() == 0) return;
				synchronized (mCountdownVHList) {
					long currentTime = System.currentTimeMillis();
					int key;
					for (int i = 0; i < mCountdownVHList.size(); i++) {
						key = mCountdownVHList.keyAt(i);
						MyViewHolder curMyViewHolder = mCountdownVHList.get(key);
						if (currentTime >= curMyViewHolder.getBean().getEndTime()) {
							curMyViewHolder.getBean().setCountdown(0);// 倒计时结束
							mCountdownVHList.remove(key);
							notifyDataSetChanged();
						} else {
							curMyViewHolder.refreshTime(currentTime);
						}
					}
				}
			}
		};
	}
	
	static class MyViewHolder extends RecyclerView.ViewHolder {
		private TextView mTvTitle;
		private CountdownView mCvCountdownView;
		private ItemInfo mItemInfo;
		
		public MyViewHolder(View itemView) {
			super(itemView);
			mTvTitle = (TextView) itemView.findViewById(R.id.tv_title);
			mCvCountdownView = (CountdownView) itemView.findViewById(R.id.cv_countdownView);
		}
		
		public void bindData(ItemInfo itemInfo) {
			mItemInfo = itemInfo;
			if (itemInfo.getCountdown() > 0) {
				refreshTime(System.currentTimeMillis());
			} else {
				mCvCountdownView.allShowZero();
			}
			mTvTitle.setText(itemInfo.getTitle());
		}
		
		public void refreshTime(long curTimeMillis) {
			if (null == mItemInfo || mItemInfo.getCountdown() <= 0) return;
			mCvCountdownView.updateShow(mItemInfo.getEndTime() - curTimeMillis);
		}
		
		public ItemInfo getBean() {
			return mItemInfo;
		}
	}
	
	static class ItemInfo {
		private int id;
		private String title;
		private long countdown;
		/*
		   根据服务器返回的countdown换算成手机对应的开奖时间 (毫秒)
		   [正常情况最好由服务器返回countdown字段，然后客户端再校对成该手机对应的时间，不然误差很大]
		 */
		private long endTime;
		
		public ItemInfo(int id, String title, long countdown) {
			this.id = id;
			this.title = title;
			this.countdown = countdown;
		}
		
		public int getId() {
			return id;
		}
		
		public void setId(int id) {
			this.id = id;
		}
		
		public String getTitle() {
			return title;
		}
		
		public void setTitle(String title) {
			this.title = title;
		}
		
		public long getCountdown() {
			return countdown;
		}
		
		public void setCountdown(long countdown) {
			this.countdown = countdown;
		}
		
		public long getEndTime() {
			return endTime;
		}
		
		public void setEndTime(long endTime) {
			this.endTime = endTime;
		}
	}
	
}

2017-6-12

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