从Android的广播接收器中查找跑步活动

Question

I want to find from within my broadcast receiver what other activities are currently running. This is the code that i use from an activity to find the other running activites but when i try to use this code in my broadcast receiver i get errors on the following lines:

ActivityManager am = (ActivityManager)this.getSystemService(ACTIVITY_SERVICE);

shows the error in eclipse ACTIVITY_SERVICE cannot be resolved to a variable

 PackageManager pm = this.getPackageManager();

and this shows the error in eclipse The method getPackageManager() is undefined for the type ScreenReceiver (my broadcast receiver)

Here is the full code:

public void getRunning(){
        ActivityManager am = (ActivityManager)this.getSystemService(ACTIVITY_SERVICE);
        List l = am.getRunningAppProcesses();
        Iterator i = l.iterator();
        PackageManager pm = this.getPackageManager();
        while(i.hasNext()) {
          ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo)(i.next());
          try {
            CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(info.processName, PackageManager.GET_META_DATA));
            Log.w("LABEL", c.toString());
            runningApplications.add(c.toString());
          }catch(Exception e) {
            //Name Not Found Exception
          }
        }

    }

Answer 1

Since BroadcastReceiver does not descent from a Context, you cannot use this , as you can do in Activity. You should use the instance of Context that is passed to your onReceive() method.

public void getRunning(Context context){
        ActivityManager am = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
        List l = am.getRunningAppProcesses();
        Iterator i = l.iterator();
        PackageManager pm = context.getPackageManager();
        while(i.hasNext()) {
          ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo)(i.next());
          try {
            CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(info.processName, PackageManager.GET_META_DATA));
            Log.w("LABEL", c.toString());
            runningApplications.add(c.toString());
          }catch(Exception e) {
            //Name Not Found Exception
          }
        }

    }

Answer 2

try as:

public class ScreenReceiver  extends BroadcastReceiver {
private Context ctext;
    @Override
    public void onReceive(Context context, Intent intent) {
      ctext=context;
         //OR you can also pass context as param to  getRunning()
      //your code here....
    }
public void getRunning(){
        ActivityManager am = (ActivityManager)ctext.getSystemService(Context.ACTIVITY_SERVICE);
        List l = am.getRunningAppProcesses();
        Iterator i = l.iterator();
        PackageManager pm = ctext.getPackageManager();
        while(i.hasNext()) {
          ActivityManager.RunningAppProcessInfo info = (ActivityManager.RunningAppProcessInfo)(i.next());
          try {
            CharSequence c = pm.getApplicationLabel(pm.getApplicationInfo(info.processName, PackageManager.GET_META_DATA));
            Log.w("LABEL", c.toString());
            runningApplications.add(c.toString());
          }catch(Exception e) {
            //Name Not Found Exception
          }
        }

    }

}