我已经看到很多关于如何有目的地连接到多个设备的问题。但在我的情况下，我只尝试连接到一个硬件设备。
我有两个硬件设备应该做同样的事情。当他们通过 BLE 连接到我的应用程序时，他们的 LED 会变成纯色。当我只打开一个设备时，这一切都很好。但是，当我打开两台设备然后尝试仅连接一台时。两个设备的 LED 都变为常亮。尽管我似乎没有从我不打算连接的数据中获取任何传入数据。
我不认为这是设备的错。因为我在 iOS 上没有这个问题。我认为手机可能会在某个地方记住以前连接的设备？
对不起，这是很多代码。但我觉得这门课很重要。任何帮助深表感谢。
package com.roberts.croberts.orange;
import android.annotation.TargetApi;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothProfile;
import android.bluetooth.le.ScanCallback;
import android.bluetooth.le.ScanResult;
import android.content.Context;
import android.os.Build;
import android.os.Handler;
import android.util.Log;
import android.bluetooth.le.BluetoothLeScanner;
import java.util.ArrayList;
import java.util.List;
@TargetApi(21)
public class BluetoothRegulator {
private static BluetoothRegulator instance = null;
private Context context;
private BluetoothLeScanner mLEScanner;
private BluetoothDevice orangeDevice;
//scanner stuff
private Handler mHandler;
// Stops scanning after 3 seconds.
private static final long SCAN_PERIOD = 3000;
//connected stuff
private android.bluetooth.BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private BluetoothGatt mBluetoothGatt;
public ArrayList<BluetoothDevice> devices = new ArrayList<>();
private Handler foundHandler = new Handler();
private Handler servicesHandler = new Handler();
private ScanCallback mScanCallback;
public static BluetoothRegulator sharedInstance(){
if(instance == null) {
instance = new BluetoothRegulator();
Log.i("chase", "created new instance");
}
return instance;
}
// Implements callback methods for GATT events that the app cares about. For example,
// connection change and services discovered.
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
mBluetoothGatt.discoverServices();
Log.i(TAG, "BR: onconnectionsStateChanged Connected to GATT server.");
// Attempts to discover services after successful connection.
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
Log.i(TAG, "Disconnected from GATT server.");
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
// Loops through available GATT Serviceokay so ees.
for (BluetoothGattService gattService : mBluetoothGatt.getServices()) {
for (BluetoothGattCharacteristic gattCharacteristic : gattService.getCharacteristics()) {
mBluetoothGatt.setCharacteristicNotification(gattCharacteristic, true);
Log.i(TAG, mBluetoothGatt == null ? "mbluetooth is null" : "should be subscribed");
}
}
Log.i("chase", "did connect and discover devices");
} else {
Log.w(TAG, "Not Success onServicesDiscovered received: " + status);
connect(orangeDevice);
}
}
private Object getFieldFromObject(Object obj, String name){
try {
Field field = obj.getClass().getDeclaredField(name);
field.setAccessible(true);
return field.get(obj);
}catch(Exception e){
Log.i("chase", "e: "+e);
return null;
}
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic) {
Log.i("BR: chase", "received data!");
}
};
public void close() {
if (mBluetoothGatt == null) {
return;
}
mBluetoothGatt.close();
mBluetoothGatt = null;
}
public boolean initialize(android.bluetooth.BluetoothManager btmanager, Context ctx) {
mBluetoothManager = btmanager;
context = ctx;
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
return false;
}
if (Build.VERSION.SDK_INT >= 21) {
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
setUpCallBack();
}
return true;
}
public void scan() { //we call scan when they hit the connect button...
// Stops scanning after a pre-defined scan period.
Log.i("chase", "start scanning");
devices = new ArrayList<>();
if (mHandler == null) mHandler = new Handler();
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
}
}, SCAN_PERIOD);
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mLEScanner.startScan(mScanCallback);
}
}
private void foundDevice(BluetoothDevice device){
final String deviceName = device.getName();
if (deviceName != null && deviceName.length() > 5 && (deviceName.substring(0, 6).equals("orange") || deviceName.substring(0, 6).equals("smartb"))) {
for (BluetoothDevice d : devices){
if (d.getAddress().equals(device.getAddress())){
return;
}
}
mHandler.removeCallbacksAndMessages(null);
devices.add(device);
if (devices.size() == 1) { //wait one second and then assume there aren't any more devices named "orange"
foundHandler.postDelayed(new Runnable() {
public void run() {
doneSearching();
}
}, 1000);
}
}
}
private void doneSearching(){
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
if (devices.size() == 1){
BluetoothDevice device = devices.get(0);
connect(device);
}else{
//normally this displays a list and the user can choose which device. But this works just as well for now.
BluetoothDevice device = devices.get(0);
connect(device);
}
}
//connect method
public boolean connect(BluetoothDevice btdevice) {
orangeDevice = btdevice;
if (mBluetoothAdapter == null || btdevice == null || btdevice.getAddress() == null) {
return false;
}
if (Build.VERSION.SDK_INT < 21) {
mBluetoothAdapter.stopLeScan(mLeScanCallback);
} else {
mLEScanner.stopScan(mScanCallback);
}
devices = new ArrayList<>();
mBluetoothGatt = orangeDevice.connectGatt(context, true, mGattCallback);
return true;
}
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) return;
mBluetoothGatt.disconnect();
mBluetoothGatt = null;
}
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
foundDevice(device);
}
};
public void setUpCallBack(){
mScanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
BluetoothDevice device = result.getDevice();
foundDevice(device);
}
@Override
public void onScanFailed(int errorCode) {
Log.e("Chase", "Scan Failed Error Code: " + errorCode);
}
};
}
}
更新
我正在玩银河平板电脑，但无法重现该问题。所以我认为这取决于设备。问题出现在 Galaxy S3 上，我正在尝试收集其他一些设备进行测试。
此外，我能够接触到一些新设备，并且似乎如果该设备以前从未连接到手机（原始设备），那么该设备不会混淆并认为它没有连接。所以我们会在搜索时看到它，但它从不认为我正在连接到它，直到我真正连接到它。在那之后，有一半的时间它认为我正在尝试与它交谈，而我却不是。我希望这是有道理的。这支持了手机以某种方式缓存旧设备的理论。我尝试卸载该应用程序并重新安装它以查看它是否与使用原始设备具有相同的效果，但似乎该应用程序与它无关。即使我重新安装了该应用程序，该设备在被引入手机后仍会连接（当它不应该连接时）。