我在学校有一个项目的 android 应用程序。该应用程序的目标是获取 GPS 位置，扫描可用的 wifi 网络，并将该信息捆绑到要发布的字符串中（也由应用程序发送）。gps 和 wifi 部分是从头开始编写的，而 twitter 代码是我的一位队友发现的一些开源内容。我们中没有人以前有任何 android 编程经验，所以我们一直在学习我们只需要飞行的东西。该应用程序现在可以正常工作，但还不够好。它通常可以关闭一些推文，但最终总是会收到 ANR。我认为这可能来自 GPS 或 WIFI 代码，因为这是我们自己编写的。我们只用 twitter 代码编写了一个单独的应用程序来测试它，它似乎工作正常，所以我不这么认为'
一些有更多经验的 android 程序员是否可以查看其中的一些代码并指出他们看到的任何问题，特别是可能导致该应用程序 ANR 的原因？此外，如果有人愿意提出比我们目前拥有的更好的架构/框架，我会很感兴趣。当应用程序运行时，我们最终会发送一条类似于下面这样的推文：
ajd7v-34 U0b0ed38fc_ _ __ _ __ _ __ _ __ _ __ _ __ _ _ 00b0ed39c4 _ __ _ __ _ __ _ __ _ __ _ __ _ _ _W0b0edf50c+44974893-093232387
这是我们活动类的相关代码......
private Intent in;
public static TextView textView1;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spectral_tweets);
mConsumer = new CommonsHttpOAuthConsumer(CONSUMER_KEY, CONSUMER_SECRET);
mProvider = new DefaultOAuthProvider(
"http://api.twitter.com/oauth/request_token",
"http://api.twitter.com/oauth/access_token",
"http://api.twitter.com/oauth/authorize");
prefs = PreferenceManager.getDefaultSharedPreferences(this);
String token = prefs.getString("token", null);
String tokenSecret = prefs.getString("tokenSecret", null);
if (token != null && tokenSecret != null) {
mConsumer.setTokenWithSecret(token, tokenSecret);
oauthClient = new OAuthSignpostClient(CONSUMER_KEY,
CONSUMER_SECRET, token, tokenSecret);
twitter = new Twitter(TWITTER_USER, oauthClient);
} else {
Log.d(TAG, "onCreate. Not Authenticated Yet " );
new OAuthAuthorizeTask().execute();
}
in = new Intent(this, BackgroundService.class);
textView1 = (TextView) findViewById(R.id.textView1);
changeText("On Create");
}
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_spectral_tweets, menu);
return true;
}
/**
* Changes textView1 to string msg
*/
public static void changeText(String msg) {
textView1.setText(msg);
}
/**
* tell the service to start displaying GPS/WIFI updates
*/
public void startMessages(View view) {
startService(in);
}
/**
* tell the service to stop displaying GPS/WIFI updates
*/
public void stopMessages(View view) {
changeText("stopped");
stopService(in);
}
/**
* When the BACK key is pressed ask the user if they want to quit
* if they do then stop the service and exit the program
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
@SuppressWarnings("unused")
AlertDialog alertbox = new AlertDialog.Builder(this)
.setMessage("Do you want to exit the application?")
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
// stop the service and end the program
public void onClick(DialogInterface arg0, int arg1) {
stopService(in);
finish();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
// return to program
public void onClick(DialogInterface arg0, int arg1) {}
})
.show();
}
return super.onKeyDown(keyCode, event);
}
这是我们服务中处理 gps 和 wifi 的代码......
public class BackgroundService extends Service implements LocationListener
{
private static Timer repeater = new Timer();
private static LocationManager lm;
private getInfoAndTweet getAndTweet = this.new getInfoAndTweet();
private static final int MIN_TIME_MILLISECONDS = 0;
private static final int MIN_DIST_METERS = 0;
private static final int frequency = 30 * 1000;
private double temp_long = 0.0;
private double temp_lat = 0.0;
private int temp_count = 0;
private boolean thread_running = false;
@Override
public IBinder onBind(Intent arg0) {
return null;
}
public void onCreate()
{
super.onCreate();
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_MILLISECONDS, MIN_DIST_METERS, this);
Toast.makeText(getApplicationContext(), "Location display is on", Toast.LENGTH_SHORT).show();
startService();
}
public void onDestroy()
{
repeater.cancel();
lm.removeUpdates(this);
unregisterReceiver(getAndTweet.receiver);
Toast.makeText(getApplicationContext(), "Location display is off", Toast.LENGTH_SHORT).show();
temp_lat = 0;
temp_long = 0;
temp_count = 0;
}
private void startService()
{
repeater.scheduleAtFixedRate(getAndTweet, 0, frequency);
}
/* this class will contain all of the GPS and WIFI classes so that none of that stuff clogs up the main thread */
private class getInfoAndTweet extends TimerTask
{
WifiManager wifi;
BroadcastReceiver receiver;
DecimalFormat lat = new DecimalFormat("00.000000");
DecimalFormat lon = new DecimalFormat("000.000000");
String gps_info;
String wifi_info;
String final_string;
private final String hashtag = "#ajd7v-34 ";
int count = 0;
private class WIFIscanner extends BroadcastReceiver
{
private final ArrayList<Integer> channel_numbers = new ArrayList<Integer> (Arrays.asList(0, 2412, 2417, 2422, 2427, 2432, 2437, 2442, 2447, 2452, 2457, 2462));
List <ScanResult> results;
Map<Integer, String> levels = new HashMap<Integer, String>();
String empty_channel = "__________"; // 10 spaces
public WIFIscanner()
{
init_levels();
}
public void onReceive(Context context, Intent intent)
{
wifi_info = "";
results = wifi.getScanResults();
ScanResult sr;
Iterator<ScanResult> it = results.iterator();
ScanResult channel_info[] = new ScanResult[12];
for (int i = 1; i < 12; i++)
{
channel_info[i] = null;
}
while (it.hasNext())
{
sr = it.next();
int channel = channel_numbers.indexOf(Integer.valueOf(sr.frequency));
if (channel_info[channel] == null)
{
channel_info[channel] = sr;
}
else
{
if (channel_info[channel].level < sr.level)
{
channel_info[channel] = sr;
}
}
}
for (int i = 1; i < 12; i++)
{
if (channel_info[i] != null)
{
wifi_info += (levels.get(channel_info[i].level) == null ? "0" : levels.get(channel_info[i].level)) + channel_info[i].BSSID.replace(":", "").substring(2, 11);
}
else
{
wifi_info += empty_channel;
}
}
final_string = hashtag + wifi_info + gps_info;
if (temp_count != 0)
{
if(Twitter_Test_AppActivity.twitter != null) {
Twitter_Test_AppActivity.twitter.setStatus(final_string);
Twitter_Test_AppActivity.changeText("Auto Tweet Sent: " + count + "\t" + final_string);
} else {
Twitter_Test_AppActivity.changeText("Tweet not sent");
}
}
else
{
Twitter_Test_AppActivity.changeText(count + "\tno new GPS info");
}
thread_running = false;
}
}
public void run()
{
thread_running = true;
wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (receiver == null)
{
receiver = new WIFIscanner();
}
registerReceiver(receiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
String latitude = lat.format(temp_lat / temp_count).replace(".", "");
String longitude = lon.format(temp_long / temp_count).replace(".", "");
gps_info = ((temp_lat / temp_count) > 0 ? "+" : "") + latitude + ((temp_long / temp_count) > 0 ? "+" : "") + longitude;
wifi.startScan();
count++;
}
}
public void onLocationChanged(Location location) {
if (thread_running)
{
temp_lat += location.getLatitude();
temp_long += location.getLongitude();
temp_count ++;
}
}
public void onProviderDisabled(String provider) {
Toast.makeText(getApplicationContext(), "GPS disabled", Toast.LENGTH_SHORT).show();
}
public void onProviderEnabled(String provider) {
Toast.makeText(getApplicationContext(), "GPS enabled", Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
编辑当我更多地考虑这个问题时，我想到在主线程上运行的 twitter 代码也可能导致我的 ANR。学校的网络不是最好的，我的笔记本电脑有时甚至无法上网（不是我的笔记本电脑的错，其他地方都很好）。尝试发送推文时，网络连接缓慢或不良是否会导致我的主线程挂断，从而导致手机 ANR 我的应用程序？