回答:特别感谢下面的 Nelson Hoang 指导我朝着正确的方向前进并提供宝贵的资源。添加位置权限代码后(请参阅下面的 Edit2)，我必须手动进入设置并打开应用程序的位置权限。完成后，它运行良好。
问题:我正在尝试使用来自 android studio 的标准蓝牙 LE Gatt 连接到蓝牙 LE 设备。我每次都被迫将 gradle 从 2.8 更新到 2.10。我已经在不同的项目上自动和手动完成了这项工作。
然而，一旦我在我的 Galaxy S7 上下载了这个应用程序，它扫描并没有发现任何东西，尽管它们旁边有 3 个蓝牙 LE 设备在广播。我知道这不是我的 S7 的硬件问题，因为我使用的是 Bluefruit LE 并且能够接收信号并正常连接。有什么解决办法吗？
编辑:按照建议，我将在下面发布扫描代码。然而，这些实际上都不是我写的。这是您可以从 Android Studio 访问的蓝牙 LE 示例代码。
Edit2:为了授予我添加到 list 中的应用定位权限:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
这是对通常的蓝牙包的补充，但它没有改变任何东西。
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;
/**
* 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();
// 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;
}
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;
}
}
最佳答案
您是否开启了定位功能？ Android 6.0+ 设备需要打开位置才能扫描蓝牙 LE 外围设备。 Bluetooth Low Energy startScan on Android 6.0 does not find devices
关于android - 蓝牙 Le Gatt 找不到任何设备，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37423199/