我正在开发一个应用程序，我必须在其中连接到 Android 4.3 上的蓝牙设备。
我有两个 java 文件，一个是DeviceControl extends Activity另一个是BluetoothLeService extends Service.
我在BluetoothLeService.java中调用该函数，我希望它将rssi值返回给DeviceControl.java。
我mRssi = intent.getStringExtra(EXTRAS_DEVICE_RSSI);在DeviceControl.java中使用，它将从BluetoothLeService.java中的rssi接收值。
但它总是显示DeviceControl.java中的值为 null。
为什么 mRssi 的值为空？
这是BluetoothLeService.java中的函数
public class BluetoothLeService extends Service {
public final static String ACTION_RSSI_VALUE_READ = "com.example.bluetooth.le.ACTION_RSSI_VALUE_READ";
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public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
//super.onReadRemoteRssi(gatt, rssi, status);
if(status == BluetoothGatt.GATT_SUCCESS) {
final Intent intent = new Intent();
intent.setAction(ACTION_RSSI_VALUE_READ);
broadcastUpdate(ACTION_RSSI_VALUE_READ, rssi);
//call and send the intent and rssi to broadcastUpdate function
}
}
//broadcastUpdate function receive the intent and rssi value, and transmit to the DeviceControl.java by using sendBroadcast.
private void broadcastUpdate(final String action, final int rssi) {
final Intent intent = new Intent(action);
intent.putExtra(DeviceControl.EXTRAS_DEVICE_RSSI, rssi);
Log.v(TAG, "rssi action = " + action);
Log.v(TAG, "RSSI = " + rssi);
sendBroadcast(intent);
}
private void broadcastUpdate(final String action) {
final Intent intent = new Intent(action);
sendBroadcast(intent);
}
private void broadcastUpdate(final String action, final BluetoothGattCharacteristic characteristic) {
final Intent intent = new Intent(action);
final byte[] data = characteristic.getValue();
if (data != null && data.length > 0) {
final StringBuilder stringBuilder = new StringBuilder(data.length);
for(byte byteChar : data)
stringBuilder.append(String.format("%02X", byteChar));
intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString());
}
sendBroadcast(intent);
}
以及DeviceControl.java中的代码
public class DeviceControl extends Activity {
public static final String EXTRAS_DEVICE_RSSI = "DEVICE_RSSI";
private String mRssi;
private final BroadcastReceiver mGattUpdateReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
final String action = intent.getAction();
final Intent intent = getIntent();
mRssi = intent.getStringExtra(EXTRAS_DEVICE_RSSI); //Use **mRssi** to receive the value from BluetoothLeService.java
Log.d(TAG, "mRssi = " + mRssi);
if(BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) {
mConnect = true;
updateConnectionState(R.string.connected);
invalidateOptionsMenu();
} else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) {
mConnect = false;
updateConnectionState(R.string.disconnected);
invalidateOptionsMenu();
} else if (BluetoothLeService.ACTION_RSSI_VALUE_READ.equals(action)) {
mRssi = intent.getStringExtra(EXTRAS_DEVICE_RSSI);
Log.v(TAG, "mRssi == :" + mRssi);
}//if the action is EXTRAS_DEVICE_RSSI, receive the rssi value
}
};
编辑
BluetoothLeService.java中的代码 修改了onReadRemoteRssi和broadcastUpdate的代码。
DeviceControl.java中的代码在onReceive中 添加从intent接收值的代码
我从日志文件中看到了日志，它在BluetoothLeService.java中的 broadcastUpdate 函数中显示了日志消息，如下所示：
Log.v(TAG, "rssi action = " + action);
Log.v(TAG, "RSSI = " + rssi);
但我没有看到任何关于action = EXTRAS_DEVICE_RSSI的日志。我不知道是 sendBroadcast 没有发送还是onReceive没有调用？？？