this article
to fix a bug of
Android BLE google example
this solution mentions on "Location permission" of android.
BLE service actually requests GPS hardware of your phone
ref：https://stackoverflow.com/questions/33043582/bluetooth-low-energy-startscan-on-android-6-0-does-not-find-devices/33045489#33045489
files to modify：
1. AndroidManifest.xml
2. DeviceScanActivity.java
1. AndroidManifest.xml
focus on the order of <uses-permission>
<?xml version="1.0" encoding="UTF-8"?> <!-- Copyright 2013 The Android Open Source Project Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.bluetoothlegatt" android:versionCode="1" android:versionName="1.0"> <!-- Min/target SDK versions (<uses-sdk>) managed by build.gradle --> <!-- Declare this required feature if you want to make the app available to BLE-capable devices only. If you want to make your app available to devices that don't support BLE, you should omit this in the manifest. Instead, determine BLE capability by using PackageManager.hasSystemFeature(FEATURE_BLUETOOTH_LE) --> <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> <uses-permission android:name="android.permission.BLUETOOTH" /> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> <uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/> <application android:label="@string/app_name" android:icon="@mipmap/ic_launcher" android:roundIcon="@mipmap/ic_launcher_round" android:theme="@android:style/Theme.Holo.Light"> <activity android:name=".DeviceScanActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> <activity android:name=".DeviceControlActivity"/> <service android:name=".BluetoothLeService" android:enabled="true"/> </application> </manifest>
2. DeviceScanActivity.java
add to import statement
add to DeviceScanActivity class
add to onCreate funciton
/* * Copyright (C) 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.bluetoothlegatt; import android.app.Activity; import android.app.ListActivity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothManager; import android.content.Context; import android.content.Intent; 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; import android.Manifest; import android.os.Build; import android.util.Log; /** * 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; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); getActionBar().setTitle(R.string.title_devices); mHandler = new Handler(); //alex https://stackoverflow.com/questions/37423199/bluetooth-le-gatt-not-finding-any-devices/37423244#37423244 Log.d(TAG, "Request Location Permissions:"); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_CODE); } // 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; } //alex private static int PERMISSION_REQUEST_CODE = 1; private final static String TAG = DeviceScanActivity.class.getSimpleName(); @Override public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { if(requestCode == PERMISSION_REQUEST_CODE) { //Do something based on grantResults if(grantResults[0] == PackageManager.PERMISSION_GRANTED) { Log.d(TAG, "coarse location permission granted"); } else { Log.d(TAG, "coarse location permission denied"); } } } @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(); // 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); } } // 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; 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; } 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(); } // 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); } } 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; } }
reference：
1.https://github.com/googlesamples/android-BluetoothLeGatt/issues/22
2.https://stackoverflow.com/questions/37423199/bluetooth-le-gatt-not-finding-any-devices
3.https://stackoverflow.com/questions/33043582/bluetooth-low-energy-startscan-on-android-6-0-does-not-find-devices/33045489#33045489
沒有留言:
張貼留言