Question

我想检查当前正在运行的应用程序是否匹配显示消息。这是我的服务代码

public class MyService extends Service{

Context context;
ActivityManager am ;
List<ActivityManager.RunningAppProcessInfo> runningAppProcessInfo;
Dbheltool db;
String packname;
String key;

HashMap<String, String> list;
public MyService(Context context) {
    // TODO Auto-generated constructor stub4
    this.context=context;
    db=new Dbheltool(context);
}


@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}
@Override
public void onCreate() {
    // TODO Auto-generated method stub
    super.onCreate();
    Toast.makeText(this, "The new Service was Created", Toast.LENGTH_LONG).show();

    am = (ActivityManager) getSystemService(context.ACTIVITY_SERVICE);
    runningAppProcessInfo = am
            .getRunningAppProcesses();
    try{
        db.open();
        list=(HashMap)db.getPackage();
        db.close();


    }catch (java.sql.SQLException e) {
        // TODO Auto-generated catch block
        Toast.makeText(context, "Exception", Toast.LENGTH_SHORT);
    }

}
@Override
public void onStart(Intent intent, int startId) {
    // TODO Auto-generated method stub
    super.onStart(intent, startId);
    Toast.makeText(this, " Service Started", Toast.LENGTH_LONG).show();
    if(isThisApplicationRunning(context)){
        Toast.makeText(context, "Success", Toast.LENGTH_SHORT).show();
    }




}

@Override
public void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
}

public boolean isThisApplicationRunning(final Context context) {

    for (final RunningAppProcessInfo app : runningAppProcessInfo) {
        try{
            if(list.get(app.processName.toString()).equals(app.processName.toString())) {
                return true
            }
        }
        catch(NullPointerException e){

        }
    }
    return false;
}

}

当我运行这个应用程序时它失败并给出Nullpointer异常并且服务停止...请帮助我如何做到这一点。我的服务目标是....＆＃34;我的服务在后台运行，并检查用户运行的应用程序。当用户点击任何应用程序时。服务检查应用程序包它匹配Hashmap对象，如果它找到hashmap对象的键和值匹配它显示吐司的当前正在运行的应用程序的包名称＆＃34;

Answer 1

nullpointer看起来像是来自你的行：

   if (list.get(app.processName).equals(app.processName)) {

您的比较声明似乎是在比较不存在的值？

另请参阅Kkudi的答案：Android: how do I check if activity is running?

它可以帮助您构建方法。

我想检查使用服务正在运行的活动

1 个答案: