3

我试图通过单击按钮获取连接的蓝牙设备的当前 RSSI 值。但是它总是只返回-32768！不知道怎么回事！但是，我能够在第一次连接时获得正确的 RSSI。

private Button.OnClickListener buttonRSSIOnClickListener = new Button.OnClickListener(){
  @Override
  public void onClick(View arg0) {
   // TODO Auto-generated method stub
   Intent intent = new Intent(BluetoothDevice.ACTION_FOUND);
   short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE);
   Toast.makeText(getApplicationContext(),"  RSSI: " + rssi + "dBm", Toast.LENGTH_SHORT).show();

  }};

任何人都可以帮助我吗？

4

1 回答 1

9

This isn't how you use an Intent. You are getting -32768 because the RSSI isn't in that Intent that you just created, and the default result you have specified is Short.MIN_VALUE (-32768).

You need to subclass BroadcastReceiver, and create an IntentFilter (or use the manifest) to so that you receive the BluetoothDevice.ACTION_FOUND intent.

You won't be able to do this "at the click of a button." You'll only get it when Android generates the ACTION_FOUND.

Here is something close. Haven't run it myself.

In onCreate():

registerReceiver(receiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));

Elsewhere:

private final BroadcastReceiver receiver = new BroadcastReceiver(){
    @Override
    public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();
        if(BluetoothDevice.ACTION_FOUND.equals(action)) {
            short rssi = intent.getShortExtra(BluetoothDevice.EXTRA_RSSI,Short.MIN_VALUE);
            Toast.makeText(getApplicationContext(),"  RSSI: " + rssi + "dBm", Toast.LENGTH_SHORT).show();
        }
    }
};

EDIT: Actually you might be able to do it on-demand if you call startDiscovery() on your BluetoothAdapter from within onClick(). That should trigger ACTION_FOUND for each device it discovers.

于 2011-08-24T02:25:28.220 回答