BluetoothAdapter.getDefaultAdapter（）抛出的RuntimeException，而不是活动 [英] BluetoothAdapter.getDefaultAdapter() throwing RuntimeException while not in Activity

问题描述

当我试图让默认的蓝牙适配器，我不在的活动，但在的TimerTask （服务）使用：

When I'm trying to get default bluetooth adapter while i'm NOT in Activity, but in TimerTask (created inside Service) by using:

BluetoothAdapter.getDefaultAdapter();

我得到以下异常：

I get the following exception:

Exception while invoking java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

我的应用程序没有任何活动 - 那么，有没有可能得到这个适配器远离活动

My application do not have any activity - so is there any possibility to get this adapter away from Activity?

推荐答案

这似乎是Android的一个bug，仍然存在于Android的4.0（冰淇淋三明治）

This appears to be a bug in Android and still exists in Android 4.0 (Ice Cream Sandwich)

要解决此，并可以调用 BluetoothAdapter.getDefaultAdapter（）从工作线程（如AsyncTask的），你所要做的就是调用 BluetoothAdapter.getDefaultAdapter（）一旦主UI线程上（如在的onCreate（）你当前活动的）。

To workaround this and be able to call BluetoothAdapter.getDefaultAdapter() from a worker thread (e.g. AsyncTask), all you have to do is call BluetoothAdapter.getDefaultAdapter() once on the main UI thread (e.g. inside the onCreate() of your current activity).

该RuntimeException的初始化期间只扔了， BluetoothAdapter.getDefaultAdapter（）仅初始化第一次调用它。随后调用它会成功，即使是在后台线程。

The RuntimeException is only thrown during initialization, and BluetoothAdapter.getDefaultAdapter() only initializes the first time you call it. Subsequent calls to it will succeed, even in background threads.

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