Question

我有一个在后台运行的服务来获取数据。我想在获得之前检查连接性。

public class DataManager extends Thread {
static final long DELAY = 170000;
Context c;
String stop;

public DataManager(Context argContext) {
    c = argContext;
    stop = "F";
 }

public void StopPlease()
{
    stop = "T";
}  
@Override
public void run() {
       while (true) { 

             try {
                 if (stop=="F")
                 {
                     if(Functions.isOnline(c))
                     {
                         //run the data table loaders for each data type

                         Log.i("MobileViaNetData", "running aircraft data update");
                         DataLoader_Aircraft acloader = new DataLoader_Aircraft(c);
                         acloader.run();
                         Thread.sleep(DELAY);
                     }
                     else
                     {
                         Thread.sleep(DELAY);
                         Toast.makeText(c, "NOT CONNECTED AT THIS TIME", Toast.LENGTH_LONG).show();
                     }
                 }
                 else {
                     break;
                 }
             } catch (InterruptedException e) {
                    e.printStackTrace();
           }
     }
   } 
}

    public class Functions {

    public static boolean isOnline(Context context) 
    {     
        ConnectivityManager cm = (ConnectivityManager)    context.getSystemService(Context.CONNECTIVITY_SERVICE);     
        NetworkInfo netInfo = cm.getActiveNetworkInfo();     
        if (netInfo != null && netInfo.isConnected()) 
        {         
            return true;     
        }     
            return false; 
    } 
}

这很有效。但是，如果我将其更改为“if（！Functions.isOnline（c））”，则检查（当没有Wi-Fi时）它会抛出错误

10-24 13:59:57.970: ERROR/AndroidRuntime(2972): FATAL EXCEPTION: Thread-12
10-24 13:59:57.970: ERROR/AndroidRuntime(2972): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

这是检查连通性的正确方法吗？

Answer 1

您正在正确检查连接，但是您的线程正在绊倒。您应该尝试使用AsyncTask或IntentService，而不是访问原始线程。对于您的特定实例，我将DataManager更改为AsyncTask，并基本上从您的run()函数逐字复制代码并将其放入doInBackground()方法中。

Android从线程检查连接

1 个答案: