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android:飞行模式下的空指针异常_Android_Nullpointerexception_Airplane - Fatal编程技术网

android:飞行模式下的空指针异常

android:飞行模式下的空指针异常,android,nullpointerexception,airplane,Android,Nullpointerexception,Airplane,我正在制作一个应用程序,在其中我必须检查设备是否处于飞行模式,我使用以下代码,它是空指针异常。我的代码如下: public static boolean isAirplaneModeOn(Context context) { System.out.println("test1"); return Settings.System.getInt(context.getContentResolver(),Settings.Sys

我正在制作一个应用程序,在其中我必须检查设备是否处于飞行模式,我使用以下代码,它是空指针异常。我的代码如下:

 public static boolean isAirplaneModeOn(Context context)
            {
    System.out.println("test1");
                    return Settings.System.getInt(context.getContentResolver(),Settings.System.AIRPLANE_MODE_ON, 0) != 0;

            }

    /**
     *
     * @param status
     */
    public  void  setAirplaneMode(Context context,boolean status)
    {System.out.println("test111");
            boolean isAirplaneModeOn = isAirplaneModeOn(context);// **null pointer exception**
            if(isAirplaneModeOn && status)
            {
                    return;
            }
            if(!isAirplaneModeOn && !status)
            {
                    return;
            }
            if(isAirplaneModeOn && !status)
            {
             Settings.System.putInt(getApplicationContext().getContentResolver(),
                    Settings.System.AIRPLANE_MODE_ON, 0);
            Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
            intent.putExtra("state", 0);
            getApplicationContext().sendBroadcast(intent);
            return;
            }
            if(!isAirplaneModeOn && status)
            {
             Settings.System.putInt(getApplicationContext().getContentResolver(),
                    Settings.System.AIRPLANE_MODE_ON, 1);
            Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);

            intent.putExtra("state", 1);

            getApplicationContext().sendBroadcast(intent);

            return;
            }
    }
    03-13 14:57:04.507: I/System.out(9185): test111
    03-13 14:57:04.507: I/System.out(9185): test1
    03-13 14:57:04.515: I/System.out(9185): java.lang.NullPointerException
有人能告诉我如何获得mAirplaneEnabled标志值吗

我的日志如下:

 public static boolean isAirplaneModeOn(Context context)
            {
    System.out.println("test1");
                    return Settings.System.getInt(context.getContentResolver(),Settings.System.AIRPLANE_MODE_ON, 0) != 0;

            }

    /**
     *
     * @param status
     */
    public  void  setAirplaneMode(Context context,boolean status)
    {System.out.println("test111");
            boolean isAirplaneModeOn = isAirplaneModeOn(context);// **null pointer exception**
            if(isAirplaneModeOn && status)
            {
                    return;
            }
            if(!isAirplaneModeOn && !status)
            {
                    return;
            }
            if(isAirplaneModeOn && !status)
            {
             Settings.System.putInt(getApplicationContext().getContentResolver(),
                    Settings.System.AIRPLANE_MODE_ON, 0);
            Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);
            intent.putExtra("state", 0);
            getApplicationContext().sendBroadcast(intent);
            return;
            }
            if(!isAirplaneModeOn && status)
            {
             Settings.System.putInt(getApplicationContext().getContentResolver(),
                    Settings.System.AIRPLANE_MODE_ON, 1);
            Intent intent = new Intent(Intent.ACTION_AIRPLANE_MODE_CHANGED);

            intent.putExtra("state", 1);

            getApplicationContext().sendBroadcast(intent);

            return;
            }
    }
    03-13 14:57:04.507: I/System.out(9185): test111
    03-13 14:57:04.507: I/System.out(9185): test1
    03-13 14:57:04.515: I/System.out(9185): java.lang.NullPointerException

npe是由上下文引起的,因为上下文在这里为null。因此代码段可能如下所示:

public  boolean isAirplaneModeOn(Context context) 
            {

            return Settings.System.getInt(ClassName.this.getContentResolver(),Settings.System.AIRPLANE_MODE_ON, 0)!=0;

            }

对于startok njzk2,您不应该在android中使用System.out,但您可以通过查看NPE中的空值来帮助我解决问题。然后解释您要查找的mAirplaneEnabled标志值是什么。context.getContentResolver,上下文为null?idottiger,给我一些解决方案,用什么来代替上下文