蓝牙应用程序不扫描可用设备

Question

我在安卓工作室制作了一个小应用程序来扫描蓝牙设备，但该应用程序没有扫描任何可用的设备并且没有显示任何错误。我手动打开蓝牙。但是当我在应用程序中按扫描按钮时，没有任何反应。我希望当我按下扫描按钮时，应该显示可用设备列表。我还在清单文件中添加了蓝牙权限。Java 和 XML

package com.example.discoverbluetoothobjects;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
    Button scanButton;
    ListView scanListView;
    ArrayList<String> stringArrayList=new ArrayList<String>();
    ArrayAdapter<String> arrayAdapter;
    BluetoothAdapter myAdapter = BluetoothAdapter.getDefaultAdapter();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        scanButton = (Button) findViewById(R.id.scanButton);
        scanListView= (ListView)findViewById(R.id.scannedListView);
        scanButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                myAdapter.startDiscovery();
            }
        });
        IntentFilter intentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(myReceiver,intentFilter);
        arrayAdapter = new ArrayAdapter<String>(getApplicationContext(),android.R.layout.simple_list_item_1,stringArrayList);
    }
    BroadcastReceiver myReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_FOUND.equals(action))
            {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                stringArrayList.add(device.getName());
                arrayAdapter.notifyDataSetChanged();
            }
        }
    };
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <Button
        android:id="@+id/scanButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:text="@string/scanButton"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <ListView
        android:id="@+id/scannedListView"
        android:layout_width="301dp"
        android:layout_height="370dp"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/scanButton" />
</android.support.constraint.ConstraintLayout>

代码附上。

Answer 1

使用此链接获取所有可用蓝牙设备及其详细信息的列表，您将找到如何连接到特定的蓝牙设备.. https://github.com/googlesamples/android-BluetoothChat