Android 秒表逻辑

我想在android中开发一个简单的秒表逻辑

单击列表视图时，计时器应启动，单击按钮时，计时器应停止。谁能给我指路吗。任何示例代码都将对使用该类有很大帮助

（为了获得更高的精度，请使用

System.nanoTime（）

）

在按下按钮时添加Start（）事件和Stop（）事件。您需要更新UI，以便使用线程/处理程序组合

这应该让你开始

编辑：添加代码。（很好的练习！：）

使用

Refresh\u Rate

配置用户界面的更新频率

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class Main extends Activity implements OnClickListener{

    final int MSG_START_TIMER = 0;
    final int MSG_STOP_TIMER = 1;
    final int MSG_UPDATE_TIMER = 2;

    Stopwatch timer = new Stopwatch();
    final int REFRESH_RATE = 100;

    Handler mHandler = new Handler()
    {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
            case MSG_START_TIMER:
                timer.start(); //start timer
                mHandler.sendEmptyMessage(MSG_UPDATE_TIMER);
                break;

            case MSG_UPDATE_TIMER:
                tvTextView.setText(""+ timer.getElapsedTime());
                mHandler.sendEmptyMessageDelayed(MSG_UPDATE_TIMER,REFRESH_RATE); //text view is updated every second, 
                break;                                  //though the timer is still running
            case MSG_STOP_TIMER:
                mHandler.removeMessages(MSG_UPDATE_TIMER); // no more updates.
                timer.stop();//stop timer
                tvTextView.setText(""+ timer.getElapsedTime());
                break;

            default:
                break;
            }
        }
    };

    TextView tvTextView;
    Button btnStart,btnStop;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        tvTextView = (TextView)findViewById(R.id.TextView01);

        btnStart = (Button)findViewById(R.id.Button01);
        btnStop= (Button)findViewById(R.id.Button02);
        btnStart.setOnClickListener(this);
        btnStop.setOnClickListener(this);

    }

    public void onClick(View v) {
        if(btnStart == v)
        {
            mHandler.sendEmptyMessage(MSG_START_TIMER);
        }else
        if(btnStop == v){
            mHandler.sendEmptyMessage(MSG_STOP_TIMER);
        }
    }
}

---

很好的例子，以防万一，如果有人想让这个布局文件与此匹配（尽管非常简单）

As通过使用类给出了一个很好的示例。我稍微修改了这个类，并添加了一些方法

/*
Copyright (c) 2005, Corey Goldberg

StopWatch.java is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

Modified: Bilal Rabbani bilalrabbani1@live.com (Nov 2013)
*/

package bilalrabbani1.at.live.com;

public class Stopwatch {
private long startTime = 0;
private boolean running = false;
private long currentTime = 0;

public void start() {
    this.startTime = System.currentTimeMillis();
    this.running = true;
}

public void stop() {
    this.running = false;
}

public void pause() {
    this.running = false;
    currentTime = System.currentTimeMillis() - startTime;
}
public void resume() {
    this.running = true;
    this.startTime = System.currentTimeMillis() - currentTime;
}

//elaspsed time in milliseconds
public long getElapsedTimeMili() {
    long elapsed = 0;
    if (running) {
         elapsed =((System.currentTimeMillis() - startTime)/100) % 1000 ;
    }
    return elapsed;
}

//elaspsed time in seconds
public long getElapsedTimeSecs() {
    long elapsed = 0;
    if (running) {
        elapsed = ((System.currentTimeMillis() - startTime) / 1000) % 60;
    }
    return elapsed;
}

  //elaspsed time in minutes
public long getElapsedTimeMin() {
    long elapsed = 0;
    if (running) {
        elapsed = (((System.currentTimeMillis() - startTime) / 1000) / 60 ) % 60;
    }
    return elapsed;
}

//elaspsed time in hours
public long getElapsedTimeHour() {
    long elapsed = 0;
    if (running) {
        elapsed = ((((System.currentTimeMillis() - startTime) / 1000) / 60 ) / 60);
    }
    return elapsed;
}

public String toString() {
    return getElapsedTimeHour() + ":" + getElapsedTimeMin() + ":"
            + getElapsedTimeSecs() + "." + getElapsedTimeMili();
}
}

---

考虑到基于IntentService、无非SDK依赖项且在单个文件上的问题

：

import android.app.Activity;
import android.app.IntentService;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class Main extends Activity {
    static final String BROADCAST_ACTION = "com.cirosantilli.android_cheat.intent_service_text_view.BROADCAST";
    static final String EXTENDED_DATA_STATUS = "com.cirosantilli.android_cheat.intent_service_text_view.BROADCAST";
    static final String TAG = "com.cirosantilli";

    private int i = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        final LinearLayout linearLayout = new LinearLayout(this);
        Button button;
        final Intent intent = new Intent(Main.this, MyService.class);

        button = new Button(this);
        button.setText("start service");
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d(TAG, "start button");
                Main.this.startService(intent.putExtra(Main.EXTENDED_DATA_STATUS, Main.this.i));
            }
        });
        linearLayout.addView(button);

        button = new Button(this);
        button.setText("stop service");
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d(TAG, "stop button");
                Main.this.stopService(intent);
            }
        });
        linearLayout.addView(button);

        final TextView textView = new TextView(this);
        textView.setText(Integer.toString(i));
        linearLayout.addView(textView);
        this.setContentView(linearLayout);

        LocalBroadcastManager.getInstance(this).registerReceiver(
                new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {
                        Main.this.i = intent.getIntExtra(Main.EXTENDED_DATA_STATUS, 0);
                        textView.setText(Integer.toString(Main.this.i));
                    }
                }, new IntentFilter(Main.BROADCAST_ACTION)
        );
    }

    public static class MyService extends IntentService {
        private Handler mHandler;
        private int i = 1;
        private boolean done;
        public MyService() {
            super("MyService");
        }
        @Override
        protected void onHandleIntent(Intent intent) {
            Log.d(TAG, "onHandleIntent");
            this.i = intent.getIntExtra(Main.EXTENDED_DATA_STATUS, 0);
            this.done = false;
            while(!done) {
                Log.d(TAG, "while true");
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
                LocalBroadcastManager.getInstance(this).sendBroadcast(
                        new Intent(Main.BROADCAST_ACTION)
                        .putExtra(Main.EXTENDED_DATA_STATUS, MyService.this.i));
                this.i++;
            }
        }
        @Override
        public void onDestroy() {
            Log.d(TAG, "onDestroy");
            this.done = true;
            super.onDestroy();
        }
    }
}

仅用于低精度。我们可以通过使用

System.currentTimeMillis

inside

onHandleIntent

来提高精度，而不是使用整数值，并减少睡眠时间以减少延迟

---

在安卓22上测试。标准构建样板。

不使用listview，您只需使用一个文本视图作为计时器，使用3个按钮作为停止-启动和重置。使用这些，您可以相应地生成java代码

很抱歉继续问这个问题……实际上，我一直在更新android中的UI。我在java中使用过这个类。但，我怎样才能用显示时间更新标签…？？我有一个简单的布局。一个标签和两个按钮。单击“开始”时计时器必须启动，单击“停止”时计时器必须停止。。。就这些。没什么复杂的。只是需要如何运行计时器和更新标签的时间…当然有标准的计时器类：你的秒表链接死了对不起，已经5年了。请参阅Bilal Rabbani答案中的实现。您不应该将一个System.currentTimeMillis的结果从另一个System.currentTimeMillis中减去，而期望得到正确的答案。每次调整机器的时钟（可以在任何时候发生），进行中的计时都将不准确。这就是Stopwatch类的用途，它专门跟踪经过的时间（以纳秒为单位）。

import android.app.Activity;
import android.app.IntentService;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class Main extends Activity {
    static final String BROADCAST_ACTION = "com.cirosantilli.android_cheat.intent_service_text_view.BROADCAST";
    static final String EXTENDED_DATA_STATUS = "com.cirosantilli.android_cheat.intent_service_text_view.BROADCAST";
    static final String TAG = "com.cirosantilli";

    private int i = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        final LinearLayout linearLayout = new LinearLayout(this);
        Button button;
        final Intent intent = new Intent(Main.this, MyService.class);

        button = new Button(this);
        button.setText("start service");
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d(TAG, "start button");
                Main.this.startService(intent.putExtra(Main.EXTENDED_DATA_STATUS, Main.this.i));
            }
        });
        linearLayout.addView(button);

        button = new Button(this);
        button.setText("stop service");
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.d(TAG, "stop button");
                Main.this.stopService(intent);
            }
        });
        linearLayout.addView(button);

        final TextView textView = new TextView(this);
        textView.setText(Integer.toString(i));
        linearLayout.addView(textView);
        this.setContentView(linearLayout);

        LocalBroadcastManager.getInstance(this).registerReceiver(
                new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {
                        Main.this.i = intent.getIntExtra(Main.EXTENDED_DATA_STATUS, 0);
                        textView.setText(Integer.toString(Main.this.i));
                    }
                }, new IntentFilter(Main.BROADCAST_ACTION)
        );
    }

    public static class MyService extends IntentService {
        private Handler mHandler;
        private int i = 1;
        private boolean done;
        public MyService() {
            super("MyService");
        }
        @Override
        protected void onHandleIntent(Intent intent) {
            Log.d(TAG, "onHandleIntent");
            this.i = intent.getIntExtra(Main.EXTENDED_DATA_STATUS, 0);
            this.done = false;
            while(!done) {
                Log.d(TAG, "while true");
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
                LocalBroadcastManager.getInstance(this).sendBroadcast(
                        new Intent(Main.BROADCAST_ACTION)
                        .putExtra(Main.EXTENDED_DATA_STATUS, MyService.this.i));
                this.i++;
            }
        }
        @Override
        public void onDestroy() {
            Log.d(TAG, "onDestroy");
            this.done = true;
            super.onDestroy();
        }
    }
}