由网友(我是你高冷的爸爸)分享简介：我想建立它使用NFC的应用程序。我们的目标是要显示DialogFragment包含按钮链接去设置和手动更改它，当启用该功能，禁止DialogFragment。问题：如果用户启用/禁用使用NFC在下拉通知图标托盘，那么在onPause / onResume不会被调用的，完全忽略了条件。我相信有一个接收器，我可以注册代替...

我想建立它使用NFC的应用程序。我们的目标是要显示DialogFragment包含按钮链接去设置和手动更改它，当启用该功能，禁止DialogFragment。

问题：如果用户启用/禁用使用NFC在下拉通知图标托盘，那么在onPause / onResume不会被调用的，完全忽略了条件。 我相信有一个接收器，我可以注册代替，并实时作出适当的反应。任何想法，想法或引用将大大AP preciated！

下面code盘，如果状态启用/禁用。我也是在onResume事件应对它正确。

  NfcManager经理=（NfcManager）getSystemService（Context.NFC_SERVICE）;
    NfcAdapter适配器= manager.getDefaultAdapter（）;

    如果（适配器= NULL和放大器;！＆安培; adapter.isEnabled（））{
        探测器=新NfcDetector（本）;
        detector.setListener（本）;
        onNfcFeatureFound（）;
    }
    其他 {
        onNfcFeatureNotFound（）;
    }
 

对于其他人看这个帖子，code以下将直接把用户进入设置，以启用/禁用NFC：

  startActivity（新意图（android.provider.Settings.ACTION_NFC_SETTINGS））;
 

解决方案

想我应该张贴其他人寻找同样问题的答案，因为我没能找到一个很容易。

添加以下code到你的活动的onCreate（）方法：

  IntentFilter的过滤器=新的IntentFilter（NfcAdapter.ACTION_ADAPTER_STATE_CHANGED）;
this.registerReceiver（mReceiver，过滤器）;
 

你的活动在

内部私有类中声明（或其他地方你想）：

 私人最终的BroadcastReceiver mReceiver =新的BroadcastReceiver（）{
    @覆盖
    公共无效的onReceive（上下文的背景下，意图意图）{
        最后弦乐行动= intent.getAction（）;

        如果（action.equals（NfcAdapter.ACTION_ADAPTER_STATE_CHANGED））{
            最终诠释状态= intent.getIntExtra（NfcAdapter.EXTRA_ADAPTER_STATE，
                                                 NfcAdapter.STATE_OFF）;
            开关（州）{
            案例NfcAdapter.STATE_OFF：
                打破;
            案例NfcAdapter.STATE_TURNING_OFF：
                打破;
            案例NfcAdapter.STATE_ON：
                打破;
            案例NfcAdapter.STATE_TURNING_ON：
                打破;
            }
        }
    }
};

@覆盖
公共无效的onDestroy（）{
    super.onDestroy（）;

    //删除广播监听器
    this.unregisterReceiver（mReceiver）;
}

  //下列检查需要也可添加到所述onResume
@覆盖
保护无效onResume（）
    super.onResume（）;
  //检查可用的NFC适配器
    PackageManager下午= getPackageManager（）;
    NfcManager经理=（NfcManager）getSystemService（Context.NFC_SERVICE）;
    NfcAdapter适配器= manager.getDefaultAdapter（）;

    如果（适配器= NULL和放大器;！＆安培; adapter.isEnabled（））{
        createNfcDetector（）;
        onNfcFeatureFound（）;
    }
    其他 {
        onNfcFeatureNotFound（）;
    }
}
 

I am trying to build an application which uses NFC. The goal is to display a DialogFragment containing a button link to go the settings and change it manually and when the feature is enabled, disable the DialogFragment.

Problem: If the user enables/disables NFC using the icon in the pull down notifications tray , then the onPause/onResume doesn't get called and misses the condition entirely. I am sure there is a receiver that I can register to instead and respond appropriately in real time. Any ideas, thoughts or reference will be greatly appreciated!

The following code checks if the state is enabled/disabled. I am also responding to it appropriately in the onResume event.

    NfcManager manager = (NfcManager) getSystemService(Context.NFC_SERVICE);
    NfcAdapter adapter = manager.getDefaultAdapter();

    if(adapter != null && adapter.isEnabled()) {
        detector = new NfcDetector(this);
        detector.setListener(this);
        onNfcFeatureFound();
    }
    else {
        onNfcFeatureNotFound();
    }

For others looking at this post, the code below will take the user directly into settings to enable/disable NFC:

startActivity(new Intent(android.provider.Settings.ACTION_NFC_SETTINGS));

解决方案

Thought I should post the answer for other people looking for the same problem, since I wasn't able to find one easily.

Add the following code to your activities onCreate() method:

IntentFilter filter = new IntentFilter(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED);
this.registerReceiver(mReceiver, filter);

Inner private class declared within your activity (or anywhere else you like):

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        final String action = intent.getAction();

        if (action.equals(NfcAdapter.ACTION_ADAPTER_STATE_CHANGED)) {
            final int state = intent.getIntExtra(NfcAdapter.EXTRA_ADAPTER_STATE,
                                                 NfcAdapter.STATE_OFF);
            switch (state) {
            case NfcAdapter.STATE_OFF:
                break;
            case NfcAdapter.STATE_TURNING_OFF:
                break;
            case NfcAdapter.STATE_ON:
                break;
            case NfcAdapter.STATE_TURNING_ON:
                break;
            }
        }
    }
};

@Override
public void onDestroy() {
    super.onDestroy();

    // Remove the broadcast listener
    this.unregisterReceiver(mReceiver);
}

  // The following check needs to also be added to the onResume
@Override
protected void onResume() 
    super.onResume();
  // Check for available NFC Adapter
    PackageManager pm = getPackageManager();
    NfcManager manager = (NfcManager) getSystemService(Context.NFC_SERVICE);
    NfcAdapter adapter = manager.getDefaultAdapter();

    if(adapter != null && adapter.isEnabled()) {
        createNfcDetector();
        onNfcFeatureFound();
    }
    else {
        onNfcFeatureNotFound();
    }
}