你好,這聽起來是一個愚蠢的question.But我無法找到這個任何答案,所以在這裏發帖。如何定期掃描藍牙設備在Android
我正在構建一個室內應用程序,它可以連續掃描位於商場或圖書館等地的不同位置的藍牙適配器。當我在商場中移動手機時,我應該能夠找到最近的加密狗我可以連接到(愚蠢的想法,但我想要做這件事)。爲此,我應該能夠不斷掃描藍牙設備。
請能有人告訴我我該如何使Android定期掃描可用的藍牙設備。
你好,這聽起來是一個愚蠢的question.But我無法找到這個任何答案,所以在這裏發帖。如何定期掃描藍牙設備在Android
我正在構建一個室內應用程序,它可以連續掃描位於商場或圖書館等地的不同位置的藍牙適配器。當我在商場中移動手機時,我應該能夠找到最近的加密狗我可以連接到(愚蠢的想法,但我想要做這件事)。爲此,我應該能夠不斷掃描藍牙設備。
請能有人告訴我我該如何使Android定期掃描可用的藍牙設備。
我想這是如此簡單,但沒有之前打我。下面是答案,
private BluetoothAdapter mBtAdapter;
mBtAdapter.startDiscovery();
private final BroadcastReceiver mReceiver = new BroadcastReceiver()
{
@Override
public void onReceive(Context context, Intent intent)
{
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action))
{
//do something
}
else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action))
{
Log.v(TAG,"Entered the Finished ");
mBtAdapter.startDiscovery();
}
因此,我們應該再次ACTION_DISCOVERY_FINISHED
這將持續每12秒設備掃描開始發現。
Awesom答案親愛的,但將它穿上」 t消耗太多battert? – 2011-07-28 05:28:27
它不與我合作:-( – 2011-07-28 07:26:30
請確保你註冊接收器 'IntentFilter intentFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED); registerReceiver(myReceiver,intentFilter);' – Raytheon 2013-06-21 03:27:31
您的代碼段應該努力 - 只是它會在電力消耗方面是昂貴的,肯定會殺了你的設備/電話在幾個小時。 startDiscovery()執行兩個步驟的過程,通過查詢找到設備,然後發現名稱,即尋呼並連接到設備,但不幸的是,Android不提供任何API來控制此操作,只做查詢,也有大多數藍牙芯片組定義和支持的定期查詢功能,Android目前沒有任何API來進行定期查詢,可能對您的使用情況更爲理想。
這裏是讓所有有效的藍牙設備列表中的代碼[成對或非成對]
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
/**
* This Activity appears as a dialog. It lists any paired devices and
* devices detected in the area after discovery. When a device is chosen
* by the user, the MAC address of the device is sent back to the parent
* Activity in the result Intent.
*/
public class DeviceListActivity extends Activity {
// Debugging
private static final String TAG = "DeviceListActivity";
private static final boolean D = true;
// Return Intent extra
public static String EXTRA_DEVICE_ADDRESS = "device_address";
// Member fields
private BluetoothAdapter mBtAdapter;
private ArrayAdapter<String> mPairedDevicesArrayAdapter;
private ArrayAdapter<String> mNewDevicesArrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Setup the window
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
setContentView(R.layout.activity_device_list);
// Initialize the button to perform device discovery
Button scanButton = (Button) findViewById(R.id.button_scan);
scanButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
doDiscovery();
v.setVisibility(View.GONE);
}
});
// Initialize array adapters. One for already paired devices and
// one for newly discovered devices
mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
mNewDevicesArrayAdapter = new ArrayAdapter<String>(this, R.layout.device_name);
// Find and set up the ListView for paired devices
ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
pairedListView.setAdapter(mPairedDevicesArrayAdapter);
pairedListView.setOnItemClickListener(mDeviceClickListener);
// Find and set up the ListView for newly discovered devices
ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
newDevicesListView.setOnItemClickListener(mDeviceClickListener);
// Register for broadcasts when a device is discovered
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(mReceiver, filter);
// Register for broadcasts when discovery has finished
filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
this.registerReceiver(mReceiver, filter);
// Get the local Bluetooth adapter
mBtAdapter = BluetoothAdapter.getDefaultAdapter();
// Get a set of currently paired devices
Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();
// If there are paired devices, add each one to the ArrayAdapter
if (pairedDevices.size() > 0) {
findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
for (BluetoothDevice device : pairedDevices) {
mPairedDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
} else {
String noDevices = getResources().getText(R.string.none_paired).toString();
mPairedDevicesArrayAdapter.add(noDevices);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
// Make sure we're not doing discovery anymore
if (mBtAdapter != null) {
mBtAdapter.cancelDiscovery();
}
// Unregister broadcast listeners
this.unregisterReceiver(mReceiver);
}
/**
* Start device discover with the BluetoothAdapter
*/
private void doDiscovery() {
if (D) Log.d(TAG, "doDiscovery()");
// Indicate scanning in the title
setProgressBarIndeterminateVisibility(true);
setTitle(R.string.scanning);
// Turn on sub-title for new devices
findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
// If we're already discovering, stop it
if (mBtAdapter.isDiscovering()) {
mBtAdapter.cancelDiscovery();
}
// Request discover from BluetoothAdapter
mBtAdapter.startDiscovery();
}
// The on-click listener for all devices in the ListViews
private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> av, View v, int i, long l) {
// Cancel discovery because it's costly and we're about to connect
mBtAdapter.cancelDiscovery();
// Get the device MAC address, which is the last 17 chars in the View
String info = ((TextView) v).getText().toString();
String address = info.substring(info.length() - 17);
}
};
// The BroadcastReceiver that listens for discovered devices and
// changes the title when discovery is finished
private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// If it's already paired, skip it, because it's been listed already
if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
mNewDevicesArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
// When discovery is finished, change the Activity title
} else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
setProgressBarIndeterminateVisibility(false);
setTitle(R.string.select_device);
if (mNewDevicesArrayAdapter.getCount() == 0) {
String noDevices = getResources().getText(R.string.none_found).toString();
mNewDevicesArrayAdapter.add(noDevices);
}
}
}
};
}
我從API演示的想法,我希望這可能是所有開發人員有用。
如documentation中所述,設備發現是一個高級過程,將直接降低您與其他設備之間所有綁定的性能。
小心:執行設備發現對於 藍牙適配器來說是一個沉重的過程,並且會消耗大量資源。一旦您找到要連接的設備,請確保在嘗試連接之前始終使用cancelDiscovery()停止 發現。另外,如果您已與設備保持連接,則執行 發現可顯着減少可用於 連接的帶寬,因此您不應在連接時執行發現。
考慮到這一點(省略處理錯誤):
private final BroadcastReceiver deviceBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
deviceFound = true;
adapter.cancelDiscovery();
//process new device.
deviceFound = false;
adapter.startDiscovery();
}
}
private final BroadcastReceiver adapterBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothAdaptor.ACTION_DISCOVERY_FINISHED.equals(action)) {
if (deviceFound == false) {
adapter.startDiscovery();
}
}
}
這是真棒的想法和夢幻般的問題,我upvoting你,快樂編碼:-) – 2011-07-28 05:27:30