uniapp原生android开发监听蓝牙状态

你可以通过使用 Android 的 BluetoothAdapter 类提供的方法来监听蓝牙的状态。以下是一个示例代码：

import android.bluetooth.BluetoothAdapter;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;

public class BluetoothStateListener {
    private BluetoothAdapter bluetoothAdapter;
    private BluetoothStateReceiver bluetoothStateReceiver;

    public BluetoothStateListener(Context context) {
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        bluetoothStateReceiver = new BluetoothStateReceiver();

        IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
        context.registerReceiver(bluetoothStateReceiver, filter);
    }

    public void unregisterReceiver(Context context) {
        context.unregisterReceiver(bluetoothStateReceiver);
    }

    private class BluetoothStateReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction().equals(BluetoothAdapter.ACTION_STATE_CHANGED)) {
                int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, -1);
                switch (state) {
                    case BluetoothAdapter.STATE_ON:
                        // 蓝牙已打开
                        break;
                    case BluetoothAdapter.STATE_OFF:
                        // 蓝牙已关闭
                        break;
                }
            }
        }
    }
}

以上代码中，我们通过注册一个 BroadcastReceiver 来监听 BluetoothAdapter.ACTION_STATE_CHANGED 广播事件，当蓝牙状态发生变化时，会触发该广播事件，我们可以在 BroadcastReceiver 的 onReceive 方法中处理蓝牙状态的变化。在使用完后，记得调用 unregisterReceiver 方法来注销 BroadcastReceiver。