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我注意到，在一個可執行文件掃描程序的情況下，掃描停止並在給定的時間段後重新開始，例如每20秒。爲什麼藍牙低能量掃描儀需要重新啓動？
這裏例如是一個掃描儀類在單獨的線程中啓動掃描儀。您可以在start()方法，線程進入睡眠一段時間看，然後掃描儀停止並重新啓動：
public class BleScanner extends Thread {
private final BluetoothAdapter bluetoothAdapter;
private final BluetoothAdapter.LeScanCallback mLeScanCallback;
private volatile boolean isScanning = false;
public BleScanner(BluetoothAdapter adapter, BluetoothAdapter.LeScanCallback callback) {
bluetoothAdapter = adapter;
mLeScanCallback = callback;
}
public boolean isScanning() {
return isScanning;
}
public void startScanning() {
synchronized (this) {
isScanning = true;
start();
}
}
public void stopScanning() {
synchronized (this) {
isScanning = false;
bluetoothAdapter.stopLeScan(mLeScanCallback);
}
}
@Override
public void run() {
try {
// Thread goes into an infinite loop
while (true) {
synchronized (this) {
// If there is not currently a scan in progress, start one
if (!isScanning) break;
bluetoothAdapter.startLeScan(mLeScanCallback);
}
sleep(Constants.SCAN_PERIOD); // Thread sleeps before stopping the scan
// stop scan
synchronized (this) {
bluetoothAdapter.stopLeScan(mLeScanCallback);
}
// restart scan on next iteration of infinite while loop
}
} catch (InterruptedException ignore) {
} finally { // Just in case there is an error, the scan will be stopped
bluetoothAdapter.stopLeScan(mLeScanCallback);
// The finally block always executes when the try block exits. This ensures that the
// finally block is executed even if an unexpected exception occurs.
}
}
}
在那裏停止和重新啓動掃描儀的任何好處？爲什麼不讓掃描繼續進行？