从哪里开始异步任务 - Android电子 [英] Where to Start Async Task - Android
问题描述
我仍然在学习Java / Android开发，我需要一些指导来实现一个异步任务。我主要不确定在哪里我的程序启动它。我在下面列出了一些code，可能有人告诉我在哪里以及如何实现的任务吗？我的应用程序发送的GPS坐标，每一秒的数据库，我需要一个单独的任务，所以我不陷入瘫痪主线程和风险的ARN错误。这里是我的code：
I'm still learning Java/Android development and I need some guidance to implement an Async task. I'm mostly unsure of where to start it in my program. I have outlined some code below, could someone show me where and how to implement the task? My app sends GPS coordinates to a database every second and I need a separate task so I don't bog down the main thread and risk an ARN error. Here is my code:
这首块是从我的主要活动。当按钮为pressed，三秒钟倒计时开始后，当它完成（onFinish）用户数据被发送到一个数据库（ SendUserActivity.sendId ... ，这实际上是一个类，而不是一个活动，刚刚入选很差），然后应用程序开始跟踪用户发送坐标到不同的数据库每秒（ location.startLocation ... ）（两个数据库，以避免重复所有的用户数据）。
This first block is from my main activity. When the button is pressed, a three second countdown is initiated, and when it finishes (onFinish) the user data is sent to one database (SendUserActivity.sendId..., this is actually a class, not an activity, just poorly named) and the app then begins to track the user and send the coordinates to a different database every second (location.startLocation...) (two databases to avoid repeating all of the user's data).
MainActivity.java：
MainActivity.java:
public void onFinish() {
button.setText("SENT");
SendUserActivity.sendId(usr_id1, first, last);
location.startLocation(getBaseContext(), usr_id1);
这是从 LocationActivity 类code的第二块（也是一类，而不是一个活动，命名又变穷了）。它要求一个位置更新每一秒，然后将其发布到了将它插入到MySQL数据库的PHP脚本。
This is the second block of code from the LocationActivity class (also a class and not an activity, poor naming again). It requests a location update every second and then posts it to a PHP script that inserts it in a MySQL database.
public class LocationActivity {
private LocationManager locManager;
private LocationListener locListener;
public void startLocation(Context context, String usr_id2)
{
final String usr = usr_id2;
//get a reference to the LocationManager
locManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//checked to receive updates from the position
locListener = new LocationListener() {
public void onLocationChanged(Location location) {
send(location, usr);
}
public void onProviderDisabled(String provider){
//labelState.setText("Provider OFF");
}
public void onProviderEnabled(String provider){
//labelState.setText("Provider ON ");
}
public void onStatusChanged(String provider, int status, Bundle extras){
//Log.i("", "Provider Status: " + status);
}
};
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, locListener);
}
public void send(Location loc, String usr_id2) {
Log.i("", String.valueOf(loc.getLatitude() + " - " + String.valueOf(loc.getLongitude())));
String lat = String.valueOf(loc.getLatitude());
String lon = String.valueOf(loc.getLongitude());
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://example.com/test/example.php");
try {
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("lat", lat));
nameValuePairs.add(new BasicNameValuePair("lon", lon));
nameValuePairs.add(new BasicNameValuePair("id", usr_id2));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
httpclient.execute(httppost);
}
catch (ClientProtocolException e) {
// TODO Auto-generated catch block
}
catch (IOException e) {
// TODO Auto-generated catch block
}
}
}
要重申我的问题，我将如何实现异步任务发送GPS信息到数据库？我看了一下IntentServices，但也有一些建议我用一个异步任务。无论哪种方式，让我知道在哪里以及如何实现其中之一;我真的AP preciate它。谢谢！
To reiterate my question, how would I implement an async task to send the GPS information to the database? I have read about IntentServices, but some have suggested that I use an async task. Either way, let me know where and how to implement one of these; I'd really appreciate it. Thanks!
推荐答案
在这种情况下，基本上你换你发送方法引入的AsyncTask的 doInBackground（）方法和结果在 onPostExecute（...）将被设置成一个数据库。让AsyncTask的一个内部类，如果你喜欢。这里是大量的如何使一个AsyncTask的例子。
这里有个例子只是一个问题
In this case basically you wrap your send method into the doInBackground() method of asynctask and a result in the onPostExecute(...) will be set into a DB. Make AsyncTask an inner class if you like. There're plenty of examples of how to make an AsyncTask.
Here for example just a question
的Android的AsyncTask和SQLite数据库实例。
本网站有很好的教程
http://www.vogella.de/articles/AndroidPerformance/article.html
和ofcourse的马克·墨菲（CommonsWare）
<一href=\"https://github.com/commonsguy/cw-lunchlist/blob/master/15-Internet/LunchList/src/apt/tutorial/FeedActivity.java\" rel=\"nofollow\">https://github.com/commonsguy/cw-lunchlist/blob/master/15-Internet/LunchList/src/apt/tutorial/FeedActivity.java
and ofcourse of Mark Murphy's (CommonsWare) https://github.com/commonsguy/cw-lunchlist/blob/master/15-Internet/LunchList/src/apt/tutorial/FeedActivity.java
干杯
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