Android 停表逻辑
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stop watch logic
提问by Rahul Kalidindi
I want to develop a simple stop watch logic in android.
我想在android中开发一个简单的秒表逻辑。
On clicking a list view the timer should start and on clicking the button the timer should stop. Can anyone please guide me. Any sample code will be of great help
单击列表视图时，计时器应启动，单击按钮时，计时器应停止。任何人都可以请指导我。任何示例代码都会有很大帮助
回答by st0le
Use the StopwatchClass (For higher precision use System.nanoTime())
使用 秒表类（用于更高的精度System.nanoTime()）
Add a Start() event and Stop() event on Button Presses. You'll need to update the UI so use a Thread/Handler Combination.
在按钮按下时添加 Start() 事件和 Stop() 事件。您需要更新 UI，因此请使用线程/处理程序组合。
This should get you started.
这应该让你开始。
EDIT: Added Code. (Nice Exercise! :) )
编辑：添加代码。（很好的练习！:)）
Use the Refresh_Rateto configure how often your UI is updated.
使用Refresh_Rate来配置 UI 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);
}
}
}
回答by Bilal Rabbani
As st0legave an excellent example by using Stopwatchclass. I modified this class a little and add a few methods to it.
正如st0le通过使用Stopwatch类给出了一个很好的例子。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 [email protected] (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();
}
}
Regards
问候
回答by Natasha Sharma
Instead of using listview you simply use a text view for timer and 3 buttons for stop start and reset . Using these you can make the java code accordingly
而不是使用列表视图，您只需将文本视图用于计时器和 3 个按钮用于停止启动和重置。使用这些你可以相应地制作java代码
回答by Waqas
Good example, just in case if someone wants that layout file to go with this (pretty simple though).
很好的例子，以防万一如果有人想要这个布局文件（虽然很简单）。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
<EditText
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginLeft="18dp"
android:layout_marginTop="49dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="@+id/Button01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/TextView01"
android:layout_marginTop="42dp"
android:layout_toRightOf="@+id/textView1"
android:text="Start" />
<Button
android:id="@+id/Button02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/Button01"
android:layout_marginTop="14dp"
android:layout_toRightOf="@+id/textView1"
android:text="Stop" />
