BluetoothLeScanner类实现蓝牙扫描

BluetoothLeScanner是Android平台上的一个API，用于实现低功耗蓝牙设备的扫描功能。它通过调用BluetoothAdapter的startLeScan方法开始扫描，并通过回调函数BluetoothAdapter.LeScanCallback返回扫描结果。需要注意的是，在使用BluetoothLeScanner进行扫描时，需要先获取蓝牙的权限，并且要实现合理的扫描策略，以减少能耗。

相关问题

BluetoothLeScanner.startScan方法代码示例实现蓝牙扫描

好的，以下是BluetoothLeScanner.startScan方法代码示例实现蓝牙扫描：

// 获取蓝牙适配器
BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter == null) {
    // 设备不支持蓝牙
    return;
}

// 获取蓝牙低功耗扫描器
BluetoothLeScanner bluetoothLeScanner = bluetoothAdapter.getBluetoothLeScanner();
if (bluetoothLeScanner == null) {
    // 设备不支持蓝牙低功耗
    return;
}

// 定义扫描过滤器，只扫描符合 UUID 的设备
List<ScanFilter> scanFilters = new ArrayList<>();
ScanFilter scanFilter = new ScanFilter.Builder()
        .setServiceUuid(ParcelUuid.fromString("0000180d-0000-1000-8000-00805f9b34fb")) // 服务 UUID
        .build();
scanFilters.add(scanFilter);

// 定义扫描设置，设置扫描模式和回调
ScanSettings scanSettings = new ScanSettings.Builder()
        .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY) // 低延迟模式
        .build();

// 开始扫描
bluetoothLeScanner.startScan(scanFilters, scanSettings, new ScanCallback() {
    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        // 扫描到设备的回调
        BluetoothDevice device = result.getDevice();
        String name = device.getName();
        String address = device.getAddress();
        int rssi = result.getRssi();

        // 处理扫描结果
        Log.d(TAG, "扫描到设备：name=" + name + ", address=" + address + ", rssi=" + rssi);
    }

    @Override
    public void onScanFailed(int errorCode) {
        // 扫描失败的回调
        Log.e(TAG, "扫描失败，errorCode=" + errorCode);
    }
});

// 停止扫描
bluetoothLeScanner.stopScan(new ScanCallback() {});

希望能够帮到你。

QT6安卓如何设置蓝牙扫描时间

在QT6 for Android中设置蓝牙扫描时间的方法与在传统的Android应用程序中设置方法相同。您需要使用Android的API来调用蓝牙扫描功能，并在代码中设置扫描的时间间隔。

以下是一些参考代码，它可以在QT6 for Android应用程序中使用来实现蓝牙扫描并设置扫描时间：

#include <QtAndroidExtras/QAndroidJniObject>
#include <QtAndroidExtras/QAndroidJniEnvironment>

void MyClass::startBluetoothScan(int scanInterval)
{
    QAndroidJniObject activity = QtAndroid::androidActivity();
    QAndroidJniObject context = activity.callObjectMethod("getApplicationContext", "()Landroid/content/Context;");

    QAndroidJniObject bluetoothManager = context.callObjectMethod("getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;", QAndroidJniObject::fromString("bluetooth").object<jstring>());

    // Set the scan interval
    QAndroidJniObject scanIntervalObject("java/lang/Integer", "(I)V", scanInterval);
    bluetoothManager.callMethod<void>("setScanInterval", "(Ljava/lang/Integer;)V", scanIntervalObject.object<jobject>());

    // Start the scan
    QAndroidJniObject bluetoothAdapter = bluetoothManager.callObjectMethod("getAdapter", "()Landroid/bluetooth/BluetoothAdapter;");
    QAndroidJniObject bluetoothLeScanner = bluetoothAdapter.callObjectMethod("getBluetoothLeScanner", "()Landroid/bluetooth/le/BluetoothLeScanner;");
    QAndroidJniObject scanCallback = QAndroidJniObject::callStaticObjectMethod("com/example/myapp/MyScanCallback", "createInstance", "()Lcom/example/myapp/MyScanCallback;");
    QAndroidJniObject scanSettingsBuilder = QAndroidJniObject::callStaticObjectMethod("android/bluetooth/le/ScanSettings$Builder", "newBuilder", "()Landroid/bluetooth/le/ScanSettings$Builder;");
    scanSettingsBuilder.callMethod<jint>("setScanMode", "(I)Landroid/bluetooth/le/ScanSettings$Builder;", 2);
    QAndroidJniObject scanSettings = scanSettingsBuilder.callObjectMethod("build", "()Landroid/bluetooth/le/ScanSettings;");
    QAndroidJniObject scanFilterBuilder = QAndroidJniObject::callStaticObjectMethod("android/bluetooth/le/ScanFilter$Builder", "newBuilder", "()Landroid/bluetooth/le/ScanFilter$Builder;");
    QAndroidJniObject scanFilter = scanFilterBuilder.callObjectMethod("build", "()Landroid/bluetooth/le/ScanFilter;");
    QAndroidJniObject scanFilters = QAndroidJniObject::fromStringArray(QStringList() << scanFilter.toString());
    bluetoothLeScanner.callMethod<void>("startScan", "(Ljava/util/List;Landroid/bluetooth/le/ScanSettings;Landroid/bluetooth/le/ScanCallback;)V", scanFilters.object<jobject>(), scanSettings.object<jobject>(), scanCallback.object<jobject>());
}

这个函数会调用Android的API来获取蓝牙管理器，并使用`setScanInterval`方法来设置扫描间隔时间。最后，它会调用`startScan`方法开始蓝牙扫描。

请注意，您需要在您的QT6 for Android项目中添加`QT += androidextras`到您的.pro文件中，以使用`QAndroidJniObject`和`QAndroidJniEnvironment`类。

希望这些信息能帮助到您！