我正在开发一个能够检测BLE信号的Android应用程序并将它们列在ListView中。扫描一段时间后,它将停止扫描。这是代码(它与开发人员页面中的代码相同):
ScanBleActivity.class(从ScanBaseActivty扩展):
public class ScanBleActivity extends ScanBaseActivity {
private BluetoothAdapter mBluetoothAdapter;
private boolean mScanning;
private Handler mHandler = new Handler();
// Stops scanning after 10 seconds.
private static final long SCAN_PERIOD = 20000;
/* (non-Javadoc)
* @see com.zishao.bletest.ScanBaseActivity#initScanBluetooth()
*/
protected void initScanBluetooth() {
BluetoothManager manager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = manager.getAdapter();
startScanLen(true);
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mScanning) {
startScanLen(false);
}
}
/**
*
* @param enable
*/
private void startScanLen(final boolean enable) {
if (enable) {
// Stops scanning after a pre-defined scan period.
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
}, SCAN_PERIOD);
mScanning = true;
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
addDevice(device, rssi);
}
};
AddDevice在其他类中实现,在本例中为ScanBaseActivity:
ScanBaseActivity(从ListActivity扩展):
abstract public class ScanBaseActivity extends ListActivity {
protected LeDeviceListAdapter mLeDeviceListAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_devices_scan);
mLeDeviceListAdapter = new LeDeviceListAdapter(this, new ArrayList<BluetoothDevice>());
this.setListAdapter(mLeDeviceListAdapter);
initScanBluetooth();
}
/**
* Start Scan Bluetooth
*
*/
abstract protected void initScanBluetooth();
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
BluetoothDevice device = (BluetoothDevice) mLeDeviceListAdapter.getItem(position);
ParcelUuid[] uuids = device.getUuids();
String uuidString = "Getting UUID's from " + device.getName() + ";UUID:";
if (null != uuids && uuids.length > 0) {
uuidString += uuids[0].getUuid().toString();
} else {
uuidString += "empty";
}
Toast.makeText(this, uuidString, Toast.LENGTH_LONG).show();
}
/**
* @param device
*/
protected synchronized void addDevice(final BluetoothDevice device, final int rssi) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.addDevice(device, rssi);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
}
}
我检测到的所有信息(名称,地址,rssi等)都列在Listview中。对于ListView,我实现了一个名为BaseAdapter的适配器。适配器的部分代码如下:
public class LeDeviceListAdapter extends BaseAdapter {
private List<BluetoothDevice> data;
private Activity context;
private final HashMap<BluetoothDevice, Integer> rssiMap = new HashMap<BluetoothDevice, Integer>();
public LeDeviceListAdapter(Activity context, List<BluetoothDevice> data) {
this.data = data;
this.context = context;
}
public synchronized void addDevice(BluetoothDevice device, int rssi) {
if(!data.contains(device) ){
data.add(device);
}
rssiMap.put(device, rssi);
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return data.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (null == convertView) {
LayoutInflater mInflater =
(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.leaf_devices_list_item, null);
convertView.setTag(new DeviceView(convertView));
}
DeviceView view = (DeviceView) convertView.getTag();
view.init((BluetoothDevice) getItem(position), null);
return convertView;
}
public class DeviceView {
private TextView title;
private TextView status;
private TextView type;
private TextView address;
private TextView rssivalue;
public DeviceView(View view) {
title = (TextView) view.findViewById(R.id.device_name);
status = (TextView) view.findViewById(R.id.device_status_txt);
type = (TextView) view.findViewById(R.id.device_type_txt);
address = (TextView) view.findViewById(R.id.device_address_txt);
rssivalue = (TextView) view.findViewById(id.signal_intensity_txt);
}
当扫描完成后,我想将ListView保存到文件中(如果可以将其保存到xml文件中),但我不知道在项目中应该使用哪些代码和哪些代码来保存它。在文件中使用时间戳来知道它何时被保存也是很重要的。谁能帮助我或给我任何线索?
新功能:已编辑代码以显示ScanBaseActivity和ScanBleActivity的所有代码!!!
答案 0 :(得分:0)
我发现你的构造函数存在一个问题。
public LeDeviceListAdapter(Activity context, List<BluetoothDevice> data) {
//EDIT::
//add the following line
super(context, R.layout.leaf_devices_list_item, data);
this.data = data;
this.context = context;
}
调用超级构造函数将数据引用传递给BaseAdapter。然后,BaseAdapter将能够处理列表中的任何更改。
答案 1 :(得分:0)
我将在这里做一些假设,如果我错了,请纠正我。 您可以从正在扫描设备的类中访问适配器。我假设您正在使用添加设备将设备添加到适配器。通过在适配器上创建返回BluetoothDevice列表的公共方法,您可以在扫描完成时从此处调用适配器以获取已存储的设备列表。 第二个选项是在将设备添加到列表时只在适配器中创建所需的xml文件。周围应该没有很多设备,所以你应该有相当少的读写。写入xml文件应遵循此答案中的步骤。 Android creating and writing xml to file
(编辑) 你会看到类似的东西:
public void run() {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
//Add the call here to save the file
// You should be able to access the list adapter from your base class
// that will give you the devices
}
}, SCAN_PERIOD);