任务:
我正在开发一个 Android 应用程序，它需要同时连接到多个(相同的，可以通过它们的 ID 区分)BLE 芯片设备，以便发送和接收更新。我用过谷歌官网的教程:
http://developer.android.com/guide/topics/connectivity/bluetooth-le.html
这帮助我创建了一个 DeviceScanActivity Java 类，它允许我扫描并列出附近的所有可用 BLE 设备，这与大多数此类应用程序当前所做的类似。我还发现最多 7 个外部从设备可以同时连接到同一个主设备。然而，实现这种沟通对我来说仍然不清楚。一个有用的链接是:
Android 4.3: How to connect to multiple Bluetooth Low Energy devices
但是，它没有提供足够的细节让我理解这样的实现是如何工作的。
我已经研究这个主题一段时间了，但没能找到任何示例实现。我知道这个问题已经被问了很多次，但似乎没有任何在线可用的有效解决方案/演示让我更清楚。如果有人能向我指出资源/工作解决方案，详细说明修改现有 Java 类以实现此功能所需的步骤，我将不胜感激。
DeviceScanActivity.java:
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
/**
* Activity for scanning and displaying available Bluetooth LE devices.
*/
public class DeviceScanActivity extends ListActivity {
private LeDeviceListAdapter mLeDeviceListAdapter;
private BluetoothAdapter mBluetoothAdapter;
private boolean mScanning;
private Handler mHandler;
private static final int REQUEST_ENABLE_BT = 1;
// Stops scanning after 10 seconds.
private static final long SCAN_PERIOD = 10000;
private static final String CONFIG_FILE = "file";
private int _countClick = 0;
private boolean experimenterMode = false;
private String pairedDeviceAddress = "";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().setTitle(R.string.title_devices);
mHandler = new Handler();
// Use this check to determine whether BLE is supported on the device. Then you can
// selectively disable BLE-related features.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
finish();
}
// Initializes a Bluetooth adapter. For API level 18 and above, get a reference to
// BluetoothAdapter through BluetoothManager.
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
// Checks if Bluetooth is supported on the device.
if (mBluetoothAdapter == null) {
Toast.makeText(this, R.string.error_bluetooth_not_supported, Toast.LENGTH_SHORT).show();
finish();
return;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
if (!mScanning) {
menu.findItem(R.id.menu_stop).setVisible(false);
menu.findItem(R.id.menu_scan).setVisible(true);
menu.findItem(R.id.menu_refresh).setActionView(null);
} else {
menu.findItem(R.id.menu_stop).setVisible(true);
menu.findItem(R.id.menu_scan).setVisible(false);
menu.findItem(R.id.menu_refresh).setActionView(
R.layout.actionbar_indeterminate_progress);
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_scan:
mLeDeviceListAdapter.clear();
scanLeDevice(true);
break;
case R.id.menu_stop:
scanLeDevice(false);
break;
case android.R.id.home:
//onBackPressed();
_countClick++;
if(_countClick>8)
{
toggleExperimenterMode();
}
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onResume() {
super.onResume();
// Ensures Bluetooth is enabled on the device. If Bluetooth is not currently enabled,
// fire an intent to display a dialog asking the user to grant permission to enable it.
if (!mBluetoothAdapter.isEnabled()) {
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
}
// Restore preferences
SharedPreferences settings = getSharedPreferences(CONFIG_FILE, 0);
experimenterMode = settings.getBoolean("experimenterMode", false);
pairedDeviceAddress = settings.getString("pairedDeviceAddress", "");
// Initializes list view adapter.
mLeDeviceListAdapter = new LeDeviceListAdapter();
setListAdapter(mLeDeviceListAdapter);
scanLeDevice(true);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// User chose not to enable Bluetooth.
if (requestCode == REQUEST_ENABLE_BT && resultCode == Activity.RESULT_CANCELED) {
finish();
return;
}
super.onActivityResult(requestCode, resultCode, data);
}
@Override
protected void onPause() {
super.onPause();
scanLeDevice(false);
mLeDeviceListAdapter.clear();
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
final BluetoothDevice device = mLeDeviceListAdapter.getDevice(position);
if (device == null) return;
connectToDevice(device);
}
private void connectToDevice(BluetoothDevice device){
final Intent intent = new Intent(this, DeviceControlActivity.class);
intent.putExtra(DeviceControlActivity.EXTRAS_DEVICE_NAME, device.getName());
intent.putExtra(DeviceControlActivity.EXTRAS_DEVICE_ADDRESS, device.getAddress());
if (mScanning) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
mScanning = false;
}
SharedPreferences settings = getSharedPreferences(CONFIG_FILE, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("pairedDeviceAddress", device.getAddress());
editor.commit();
startActivity(intent);
}
//---------------------------------------------------
private void scanLeDevice(final boolean enable) {
ProgressDialog progress;
if (enable) {
// Stops scanning after a pre-defined scan period.
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
invalidateOptionsMenu();
}
}, SCAN_PERIOD);
mScanning = true;
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
invalidateOptionsMenu();
}
private void toggleExperimenterMode(){
_countClick=0;
experimenterMode = !experimenterMode;
SharedPreferences settings = getSharedPreferences(CONFIG_FILE, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean("experimenterMode", experimenterMode);
editor.commit();
String t = experimenterMode ? "You are now in Experimenter mode":"You are now in User mode";
Toast.makeText(this, t, Toast.LENGTH_SHORT).show();
}
// Adapter for holding devices found through scanning.
private class LeDeviceListAdapter extends BaseAdapter {
private ArrayList<BluetoothDevice> mLeDevices;
private LayoutInflater mInflator;
public LeDeviceListAdapter() {
super();
mLeDevices = new ArrayList<BluetoothDevice>();
mInflator = DeviceScanActivity.this.getLayoutInflater();
}
public void addDevice(BluetoothDevice device) {
if(!mLeDevices.contains(device)) {
mLeDevices.add(device);
}
if (!experimenterMode && ! pairedDeviceAddress.isEmpty()) {
if (device.getAddress().equals(pairedDeviceAddress)) {
connectToDevice(device);
}
}
}
public BluetoothDevice getDevice(int position) {
return mLeDevices.get(position);
}
public void clear() {
mLeDevices.clear();
}
@Override
public int getCount() {
return mLeDevices.size();
}
@Override
public Object getItem(int i) {
return mLeDevices.get(i);
}
@Override
public long getItemId(int i) {
return i;
}
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder viewHolder;
// General ListView optimization code.
if (view == null) {
view = mInflator.inflate(R.layout.listitem_device, null);
viewHolder = new ViewHolder();
viewHolder.deviceAddress = (TextView) view.findViewById(R.id.device_address);
viewHolder.deviceName = (TextView) view.findViewById(R.id.device_name);
view.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) view.getTag();
}
BluetoothDevice device = mLeDevices.get(i);
final String deviceName = device.getName();
if (deviceName != null && deviceName.length() > 0)
viewHolder.deviceName.setText(deviceName);
else
viewHolder.deviceName.setText(R.string.unknown_device);
viewHolder.deviceAddress.setText(device.getAddress());
return view;
}
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mLeDeviceListAdapter.addDevice(device);
mLeDeviceListAdapter.notifyDataSetChanged();
}
});
}
};
static class ViewHolder {
TextView deviceName;
TextView deviceAddress;
}
}
当前信息:
- Android 4.3: How to connect to multiple Bluetooth Low Energy devices
- https://developer.android.com/guide/topics/connectivity/bluetooth-le.html
- Does Android 4.3 support multiple BLE device connections?
- Ble multiple connection
- https://labs.hybris.com/2014/10/06/connecting-to-multiple-ble-devices/
- https://e2e.ti.com/support/wireless_connectivity/f/538/t/225935
所有这些页面都包含一些说明，但它们没有提供有关如何实现多个连接的足够详细信息。
UI 目标表示:
我的想法是我的 5.1.1 Android Nexus 7 设备将能够连接到最多 5 个 BLE 芯片从设备并发送/接收更新。
最佳答案
我已经在 Android 中使用两台设备完成了此操作。 首先，根据我的经验，拆分代码要好得多。就我而言，我使用 a 服务进行扫描过程。使用广播接收器，我已将找到的设备对象发送到主要 Activity 。在此 Activity 中，一般只完成了我的服务导航的 ui 内容。当我的主要 Activity 接收到蓝牙设备对象时，我将此对象传输到一个单独的服务，其中仅完成蓝牙通信，并使用另一个广播接收器将接收到的数据发送回我的主要 Activity 以显示值。 如果你想连接多个设备，你可以像连接一个设备一样使用这个模式。在 LeScan Callback 的扫描仪服务中，您检查找到的设备的 Macadress。我已经创建了一个字符串数组，其中包含我想要连接的所有 Mac 地址。当我找到一个时，我已将其从阵列中删除，当您找到所有您想要的设备时，您可以停止整个服务。 此外: 我的经验是你不应该绑定(bind)你的服务。最好手动启动和停止您的服务。当我想破坏我绑定(bind)的服务时，连接保持有效，当再次连接时，我的蓝牙行为很奇怪，或者我找不到我的 Ble 服务器设备，因为它在内部仍然是绑定(bind)的。
关于安卓 4.3 : How to connect to multiple Bluetooth Low Energy devices?，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31233087/