如何在android中以编程方式启用/禁用蓝牙

Question

大家好,

我想通过程序启用/禁用蓝牙..我有以下代码.

BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();    
if (!mBluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);

但是这种代码在SDK 1.5中不起作用.我怎么能在SDK 1.5中做同样的事情.

Answer 1

这段代码对我有用..

//Disable bluetooth
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();    
if (mBluetoothAdapter.isEnabled()) {
    mBluetoothAdapter.disable(); 
} 

要使其正常工作,您必须具有以下权限:

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

Answer 2

这是一种更强大的方法,也可以处理enable()\disable()方法的返回值:

public static boolean setBluetooth(boolean enable) {
    BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    boolean isEnabled = bluetoothAdapter.isEnabled();
    if (enable && !isEnabled) {
        return bluetoothAdapter.enable(); 
    }
    else if(!enable && isEnabled) {
        return bluetoothAdapter.disable();
    }
    // No need to change bluetooth state
    return true;
}

并将以下权限添加到清单文件中:

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

但请记住以下重点:

这是一个异步调用:它将立即返回,并且客户端应该侦听ACTION_STATE_CHANGED以通知后续适配器状态更改.如果此调用返回true,则适配器状态将立即从STATE_OFF转换为STATE_TURNING_ON,稍后转换为STATE_OFF或STATE_ON.如果此调用返回false,则立即出现问题将阻止适配器打开 - 例如飞行模式,或者适配器已打开.

更新:

好的,那么如何实现蓝牙监听器？:

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

        if (action.equals(BluetoothAdapter.ACTION_STATE_CHANGED)) {
            final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,
                                                 BluetoothAdapter.ERROR);
            switch (state) {
            case BluetoothAdapter.STATE_OFF:
                // Bluetooth has been turned off;
                break;
            case BluetoothAdapter.STATE_TURNING_OFF:
                // Bluetooth is turning off;
                break;
            case BluetoothAdapter.STATE_ON:
                // Bluetooth has been on
                break;
            case BluetoothAdapter.STATE_TURNING_ON:
                // Bluetooth is turning on
                break;
            }
        }
    }
};

以及如何注册/取消注册接收器？(在你的Activity班上)

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // ...

    // Register for broadcasts on BluetoothAdapter state change
    IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
    registerReceiver(mReceiver, filter);
}

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

     // ...

    // Unregister broadcast listeners
    unregisterReceiver(mReceiver);
}

Answer 3

Android 蓝牙适配器文档称它自API级别5开始可用.API Level 5是Android 2.0.

您可以尝试使用蓝牙API的后端端口(尚未亲自尝试过):http://code.google.com/p/backport-android-bluetooth/

Answer 4

要启用蓝牙,您可以使用以下任一功能:

 public void enableBT(View view){
    BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (!mBluetoothAdapter.isEnabled()){
        Intent intentBtEnabled = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); 
        // The REQUEST_ENABLE_BT constant passed to startActivityForResult() is a locally defined integer (which must be greater than 0), that the system passes back to you in your onActivityResult() 
        // implementation as the requestCode parameter. 
        int REQUEST_ENABLE_BT = 1;
        startActivityForResult(intentBtEnabled, REQUEST_ENABLE_BT);
        }
  }

第二个功能是:

public void enableBT(View view){
    BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (!mBluetoothAdapter.isEnabled()){
        mBluetoothAdapter.enable();
    }
}

不同之处在于第一个功能使应用程序要求用户打开蓝牙或拒绝使用权限.第二个功能使应用程序直接打开蓝牙.

要禁用蓝牙,请使用以下功能:

public void disableBT(View view){
    BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (mBluetoothAdapter.isEnabled()){
        mBluetoothAdapter.disable();
    }
}

注意/第一个函数只需要在AndroidManifest.xml文件中定义以下权限:

<uses-permission android:name="android.permission.BLUETOOTH"/>

而第二和第三个函数需要以下权限:

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

Answer 5

prijin的解决方案对我来说非常合适.公平地说,需要两个额外的权限:

<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

添加这些功能后,启用和禁用默认蓝牙适配器完美无瑕.