1
我正在創建一個BLE應用程序，需要持續啓動和停止掃描預定義的時間間隔。我已經實現它的方式是有兩個可運行相互調用如下：正在停止正在運行Android
private Runnable scan = new Runnable() {
@Override
public void run() {
scanHandler.postDelayed(stopScan, SCAN_PERIOD);
mLEScanner.startScan(filters, settings, mScanCallback);
Log.e("BLE_Scanner", "Start Scan");
}
};
private Runnable stopScan = new Runnable() {
@Override
public void run() {
mLEScanner.stopScan(mScanCallback);
scanHandler.postDelayed(scan, STOP_PERIOD);
Log.e("BLE_Scanner", "Stop Scan");
}
};
我試圖開始連續掃描和暫停按鈕上點擊。開始按鈕啓動過程很好，但我在停止掃描時遇到問題。
//scan button functionality
scanButton=(Button)findViewById(R.id.scan_button);
scanButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
spinner.setVisibility(View.VISIBLE);
scan.run();
}
});
//stop scan button functionality
stopButton=(Button)findViewById(R.id.stop_button);
stopButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
spinner.setVisibility(View.INVISIBLE);
scanHandler.removeCallbacks(scan);
scanHandler.removeCallbacks(stopScan);
}
});
如果在停止間隔期間按停止按鈕，掃描將停止。但是，如果我在掃描可運行時運行時按下停止按鈕，它似乎會刪除stopScan可運行的回調，同時保持掃描可以連續運行。我需要的是兩個runnable停止按鈕按下。爲了提供更多細節，我的整個代碼在下面提供。謝謝您的幫助。
public class MainActivity extends Activity {
private BluetoothAdapter mBluetoothAdapter;
private int REQUEST_ENABLE_BT = 1;
private static final long SCAN_PERIOD = 5000;
private static final long STOP_PERIOD = 1000;
private BluetoothLeScanner mLEScanner;
private ScanSettings settings;
private List<ScanFilter> filters;
private BluetoothGatt mGatt;
private Button scanButton;
private Button stopButton;
//private String proximityUUID = "0000180f-0000-1000-8000-00805f9b34fb";
private ProgressBar spinner;
private Handler scanHandler;
private String[] filterList = {
"D9:ED:5F:FA:0E:02",
"FF:37:3A:25:56:C7",
"F4:57:89:69:93:91"
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
scanHandler = new Handler();
//determine if device supports BLE
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
Toast.makeText(this, "BLE Not Supported",
Toast.LENGTH_SHORT).show();
finish();
}
//set up bluetooth manager
final BluetoothManager bluetoothManager =
(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
//scan progress bar
spinner=(ProgressBar)findViewById(R.id.progressBar);
spinner.setVisibility(View.GONE);
//scan button functionality
scanButton=(Button)findViewById(R.id.scan_button);
scanButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
spinner.setVisibility(View.VISIBLE);
scan.run();
}
});
//stop scan button functionality
stopButton=(Button)findViewById(R.id.stop_button);
stopButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
spinner.setVisibility(View.INVISIBLE);
scanHandler.removeCallbacks(scan);
scanHandler.removeCallbacks(stopScan);
}
});
}
@Override
protected void onResume() {
super.onResume();
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
} else {
mLEScanner = mBluetoothAdapter.getBluetoothLeScanner();
//scan settings
settings = new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.build();
//scan filter
//populate the filter list
filters = new ArrayList<ScanFilter>();
for (int i=0; i< filterList.length ; i++) {
ScanFilter filter = new ScanFilter.Builder().setDeviceAddress(filterList[i]).build();
filters.add(filter);
}
}
}
@Override
protected void onPause() {
super.onPause();
if (mBluetoothAdapter != null && mBluetoothAdapter.isEnabled()) {
}
}
@Override
protected void onDestroy() {
if (mGatt == null) {
return;
}
mGatt.close();
mGatt = null;
super.onDestroy();
}
//start scan
private Runnable scan = new Runnable() {
@Override
public void run() {
scanHandler.postDelayed(stopScan, SCAN_PERIOD);
mLEScanner.startScan(filters, settings, mScanCallback);
Log.e("BLE_Scanner", "Start Scan");
}
};
private ScanCallback mScanCallback = new ScanCallback() {
@Override
public void onScanResult(int callbackType, ScanResult result) {
Log.i("callbackType", String.valueOf(callbackType));
Log.i("result", result.toString());
BluetoothDevice device = result.getDevice();
int mRSSI = result.getRssi();
}
@Override
public void onBatchScanResults(List<ScanResult> results) {
for (ScanResult sr : results) {
Log.i("ScanResult - Results", sr.toString());
}
}
@Override
public void onScanFailed(int errorCode) {
Log.e("Scan Failed", "Error Code: " + errorCode);
}
};
//stop scan
private Runnable stopScan = new Runnable() {
@Override
public void run() {
mLEScanner.stopScan(mScanCallback);
scanHandler.postDelayed(scan, STOP_PERIOD);
Log.e("BLE_Scanner", "Stop Scan");
}
};
private static double calculateAccuracy(int txPower, double rssi) {
if (rssi == 0) {
return -1.0; // if we cannot determine accuracy, return -1.
}
double ratio = -rssi*1.0/txPower;
if (ratio < 1.0) {
return Math.pow(ratio,10);
}
else {
double accuracy = (0.89976)*Math.pow(ratio,7.7095) + 0.111;
return accuracy;
}
}
}