Android。如何将 UUID 信标值设置为正确的文本视图？

Question

这是一个愚蠢的问题，但我有一个代码，它在 TextView 中为我提供了信标列表及其名称、地址、uuid、主要和次要。我正在计算 uuid、主要和次要值（在下面的代码中）。当我将这三个值设置到 TextView 中时，它们会与其他信标值交换。所以我的问题是，如何为正确的信标设置正确的 uuid、主要和次要值？

Link 举例： http://i.stack.imgur.com/vlepI.jpg

我有两个信标。名称和地址是正确的，但如您所见，uuid、主要次要是相同的，并且在扫描过程中它们不断交换信标值。

代码如下。

DeviceScanActivity

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;
private static final long SCAN_PERIOD = 10000;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getActionBar().setTitle(R.string.title_devices);
    mHandler = new Handler();

    if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
        Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
        finish();
    }

    final BluetoothManager bluetoothManager =
            (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
    mBluetoothAdapter = bluetoothManager.getAdapter();

    if (mBluetoothAdapter == null) {
        Toast.makeText(this, R.string.error_bluetooth_not_supported, Toast.LENGTH_SHORT).show();
        finish();
        return;
    }
}
@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;
    }
    return true;
}

@Override
protected void onResume() {
    super.onResume();

    if (!mBluetoothAdapter.isEnabled()) {
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
        }
    }

    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;
    //final Intent intent = new Intent(this, DeviceControlActivity.class);

    if (mScanning) {
        mBluetoothAdapter.stopLeScan(mLeScanCallback);
        mScanning = false;
    }
    //startActivity(intent);
}

private void scanLeDevice(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);
                invalidateOptionsMenu();
            }
        }, SCAN_PERIOD);

        mScanning = true;
        mBluetoothAdapter.startLeScan(mLeScanCallback);
    } else {
        mScanning = false;
        mBluetoothAdapter.stopLeScan(mLeScanCallback);
    }
    invalidateOptionsMenu();
}

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);
        }
    }

    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;
        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);
            viewHolder.deviceUUID = (TextView) view.findViewById(R.id.device_uuid);
            viewHolder.deviceMajor = (TextView) view.findViewById(R.id.device_major);
            viewHolder.deviceMinor = (TextView) view.findViewById(R.id.device_minor);
            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());
        viewHolder.deviceUUID.setText(uuid);
        viewHolder.deviceMajor.setText(major);
        viewHolder.deviceMinor.setText(minor);

        return view;
    }
}

public String uuid;
public int major_temp;
public int minor_temp;
public String major;
public String minor;


public static final char[] hexArray = "0123456789ABCDEF".toCharArray();
public static String bytesToHex(byte[] bytes) {
    char[] hexChars = new char[bytes.length * 2];
    for ( int j = 0; j < bytes.length; j++ ) {
        int v = bytes[j] & 0xFF;
        hexChars[j * 2] = hexArray[v >>> 4];
        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
    }
    return new String(hexChars);
}

public 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();
            }
        });

        int startByte = 2;
        boolean patternFound = false;
        while (startByte <= 5) {
            if (    ((int) scanRecord[startByte + 2] & 0xff) == 0x02 && //Identifies an iBeacon
                    ((int) scanRecord[startByte + 3] & 0xff) == 0x15) { //Identifies correct data length
                patternFound = true;
                break;
            }
            startByte++;
        }

        if (patternFound) {
            byte[] uuidBytes = new byte[16];
            System.arraycopy(scanRecord, startByte+4, uuidBytes, 0, 16);
            String hexString = bytesToHex(uuidBytes);

                //Here is your UUID
                uuid =  hexString.substring(0,8) + "-" +
                        hexString.substring(8,12) + "-" +
                        hexString.substring(12,16) + "-" +
                        hexString.substring(16,20) + "-" +
                        hexString.substring(20,32);

            major_temp = (scanRecord[startByte+20] & 0xff) * 0x100 + (scanRecord[startByte+21] & 0xff);
            major = Integer.toString(major_temp);
            minor_temp = (scanRecord[startByte+22] & 0xff) * 0x100 + (scanRecord[startByte+23] & 0xff);
            minor = Integer.toString(minor_temp);
          //   TextView textView1 = (TextView) findViewById(R.id.device_uuid);
            // textView1.setText(uuid+" Major: " + major + " Minor: " + minor);


        }

    }

};

static class ViewHolder {
    TextView deviceName;
    TextView deviceAddress;
    TextView deviceUUID;
    TextView deviceMajor;
    TextView deviceMinor;
}

}

和布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="wrap_content">
    <TextView android:id="@+id/device_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="24dp"/>
    <TextView android:id="@+id/device_address"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="12dp"/>
    <TextView android:id="@+id/device_uuid"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="12dp"/>
    <TextView android:id="@+id/device_major"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="12dp"/>
    <TextView android:id="@+id/device_minor"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="12dp"/>
</LinearLayout>

Answer 1

您处理找到的信标的方式存在问题。只需仔细查看您为 UUID（主要和次要）分配任何值的位置以及 ListAdapter 的内容。

在您的 LeScanCallback 中，您将找到的任何蓝牙 LE 设备添加到列表适配器中。您将它们添加为 BluetoothDevice，这只是一个通用模型，对 iBeacon 特定的 UUID、主要和次要一无所知。

然后将 UUID、major 和 minor 提取到 class 的成员变量中。这总是在找到的 BluetoothDevice 被识别为 iBeacon 时完成。在任何时候，您都只存储一组 UUID，主要和次要。它们始终是找到的最新 iBeacon 的值。

因此，您可以创建一个简单的 class 来表示具有 UUID、主要、次要以及 RSSI 和 TxPower 的 iBeacon，而不是拥有一个 BluetoothDevices 列表，如果您想稍后进行任何距离估计。然后在扫描回调中不要将 BluetoothDevices 添加到列表中，而是在模式检查代码的末尾添加 iBeacons。类似于：

public BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {

    @Override
    public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
        /* Remove:
        runOnUiThread(new Runnable() {
        @Override
            public void run() {
                mLeDeviceListAdapter.addDevice(device);
                mLeDeviceListAdapter.notifyDataSetChanged();
            }
        });
        */
        int startByte = 2;
        boolean patternFound = false;
        while (startByte <= 5) {
            if (((int) scanRecord[startByte + 2] & 0xff) == 0x02 && //Identifies an iBeacon
                    ((int) scanRecord[startByte + 3] & 0xff) == 0x15) { //Identifies correct data length
                patternFound = true;
                break;
            }
            startByte++;
        }

        if (patternFound) {
            byte[] uuidBytes = new byte[16];
            System.arraycopy(scanRecord, startByte + 4, uuidBytes, 0, 16);
            String hexString = bytesToHex(uuidBytes);

            //Here is your UUID
            uuid = hexString.substring(0, 8) + "-" +
                    hexString.substring(8, 12) + "-" +
                    hexString.substring(12, 16) + "-" +
                    hexString.substring(16, 20) + "-" +
                    hexString.substring(20, 32);

            major_temp = (scanRecord[startByte + 20] & 0xff) * 0x100 + (scanRecord[startByte + 21] & 0xff);
            major = Integer.toString(major_temp);
            minor_temp = (scanRecord[startByte + 22] & 0xff) * 0x100 + (scanRecord[startByte + 23] & 0xff);
            minor = Integer.toString(minor_temp);

            // Add:
            IBeacon iBeacon = new IBeacon(uuid, major, minor);
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    mLeDeviceListAdapter.addDevice(iBeacon);
                    mLeDeviceListAdapter.notifyDataSetChanged();
                }
            });
        }
    }
}

然后更改您的列表适配器以使用 iBeacon 对象而不是 BluetoothDevice 对象并修复 getView() 中的代码。目前，您从上述成员变量中读取 UUID、major 和 minor，它们始终具有找到的最新 iBeacon 的值。

因此，改为从现在包含 iBeacon 对象的 mLeDevices 列表中读取值。类似于：

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
    ViewHolder viewHolder;
    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);
        viewHolder.deviceUUID = (TextView) view.findViewById(R.id.device_uuid);
        viewHolder.deviceMajor = (TextView) view.findViewById(R.id.device_major);
        viewHolder.deviceMinor = (TextView) view.findViewById(R.id.device_minor);
        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());
    // Change these:
    viewHolder.deviceUUID.setText(device.getUuid);
    viewHolder.deviceMajor.setText(device.getMajor);
    viewHolder.deviceMinor.setText(device.getMinor);

    return view;
}

然后您需要修改列表适配器的 addDevice 以比较 IBeacon 对象而不是 BluetoothDevice 对象。

public void addDevice(IBeacon device) {
    // This probably won't without some extra work:        
    if(!mLeDevices.contains(device)) {
        mLeDevices.add(device);
    }
}

Android。如何将 UUID 信标值设置为正确的文本视图？

Android. How do I set UUID Beacon value to proper textview?

uuid

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bluetooth

textview

beacon