用于发现可用蓝牙设备的广播接收器

Question

我试图在我的应用程序上发现可用的蓝牙设备，但它不起作用，我认为问题出在我的广播接收器上。有人可以告诉我这个广播接收器出了什么问题吗：

package com.example.wheelchairapp;

import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

public class AvailableBroadcaseReciever extends BroadcastReceiver {
    RecyclerView.Adapter adapter2;

    public AvailableBroadcaseReciever(RecyclerView.Adapter adapter2) {
        this.adapter2 = adapter2;
    }

    @Override
    public void onReceive(Context context, @NonNull Intent intent) {
        if(BluetoothDevice.ACTION_FOUND.equals(intent.getAction())){
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) {
                return;
            }
            DevicesList.availableDevices.add(device.getName());
            adapter2.notifyDataSetChanged();
        }
    }
}

我尝试完全遵循 YouTube 开发人员的要求，但问题没有解决。

Answer 1

我不确定，也许你的权限有问题

import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.widget.Toast;

import androidx.core.app.ActivityCompat;
import androidx.recyclerview.widget.RecyclerView;

public class AvailableBroadcaseReciever extends BroadcastReceiver {
    RecyclerView.Adapter adapter2;

    public AvailableBroadcaseReciever(RecyclerView.Adapter adapter2) {
        this.adapter2 = adapter2;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        if (BluetoothDevice.ACTION_FOUND.equals(intent.getAction())) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            // Check for BLUETOOTH permission
            if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.BLUETOOTH) != PackageManager.PERMISSION_GRANTED) {
                // Request the missing permission
                // Do something here like requesting the permission or notifying the user
                // This is just an example, you may want to handle this differently based on your app's requirements
                Toast.makeText(context, "Bluetooth permission not granted", Toast.LENGTH_SHORT).show();
                return;
            }
            // You may also want to check for null device.getName() before adding it to the list
            if(device != null && device.getName() != null) {
                DevicesList.availableDevices.add(device.getName());
                adapter2.notifyDataSetChanged();
            }
        }
    }
}

确保您还在应用程序的清单文件中请求了必要的权限。你应该有这样的东西：

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

这些权限是发现蓝牙设备并与之交互所必需的。如果您的应用程序面向 Android 6.0（API 级别 23）或更高版本，请确保在运行时也请求这些权限。

Answer 2

问题是我没有使用： 导入android.Manifest， 这就是我收到错误的原因 “无法解析符号” 当我尝试添加权限时