使用startLocalOnlyHotspot创建热点无法被发现的问题及代码请求

startLocalOnlyHotspot 创建的是隐藏式WiFi热点（不主动广播SSID），所以普通设备的WiFi扫描列表无法直接发现它。另外你的代码缺少必要权限配置，也未正确获取热点的SSID和密码，导致无法正常连接。

1. 必要权限配置 #

在AndroidManifest.xml中添加以下权限：

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- Android 10+ 需添加 -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<!-- Android 12+ 需添加 -->
<uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES" />

注意：Android 6.0+需动态申请位置权限，Android 12+需动态申请NEARBY_WIFI_DEVICES权限，否则热点无法正常启动。

2. 完整可运行代码 #

import android.Manifest;
import android.content.pm.PackageManager;
import android.net.wifi.WifiManager;
import android.os.Handler;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.core.app.ActivityCompat;

public class MainActivity extends AppCompatActivity {
    private WifiManager wifiManager;
    private WifiManager.LocalOnlyHotspotReservation hotspotReservation;
    private static final int PERMISSION_REQUEST_CODE = 100;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
        // 先检查权限
        checkPermissions();
    }

    private void checkPermissions() {
        boolean hasPermissions = true;
        // Android 12+ 检查NEARBY_WIFI_DEVICES权限
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S) {
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.NEARBY_WIFI_DEVICES) != PackageManager.PERMISSION_GRANTED) {
                hasPermissions = false;
            }
        } else {
            // 低版本检查位置权限
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                hasPermissions = false;
            }
        }
        // 检查WiFi相关权限
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CHANGE_WIFI_STATE) != PackageManager.PERMISSION_GRANTED ||
                ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_WIFI_STATE) != PackageManager.PERMISSION_GRANTED) {
            hasPermissions = false;
        }

        if (!hasPermissions) {
            // 动态申请权限
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.S) {
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.NEARBY_WIFI_DEVICES,
                                Manifest.permission.CHANGE_WIFI_STATE,
                                Manifest.permission.ACCESS_WIFI_STATE},
                        PERMISSION_REQUEST_CODE);
            } else {
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION,
                                Manifest.permission.CHANGE_WIFI_STATE,
                                Manifest.permission.ACCESS_WIFI_STATE},
                        PERMISSION_REQUEST_CODE);
            }
        } else {
            // 权限已获取，启动热点
            startLocalOnlyHotspot();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSION_REQUEST_CODE) {
            boolean allGranted = true;
            for (int result : grantResults) {
                if (result != PackageManager.PERMISSION_GRANTED) {
                    allGranted = false;
                    break;
                }
            }
            if (allGranted) {
                startLocalOnlyHotspot();
            } else {
                Toast.makeText(this, "权限不足，无法启动热点", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private void startLocalOnlyHotspot() {
        if (wifiManager == null) {
            Toast.makeText(this, "无法获取WiFi服务", Toast.LENGTH_SHORT).show();
            return;
        }

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CHANGE_WIFI_STATE) != PackageManager.PERMISSION_GRANTED) {
            return;
        }

        wifiManager.startLocalOnlyHotspot(new WifiManager.LocalOnlyHotspotCallback() {
            @Override
            public void onStarted(WifiManager.LocalOnlyHotspotReservation reservation) {
                super.onStarted(reservation);
                hotspotReservation = reservation;
                // 获取热点信息
                WifiManager.LocalOnlyHotspotReservation.HotspotConfiguration config = reservation.getConfiguration();
                String ssid = config.SSID;
                String password = config.preSharedKey;

                Toast.makeText(MainActivity.this, "热点已启动\nSSID: " + ssid + "\n密码: " + password, Toast.LENGTH_LONG).show();
                // 保存reservation用于后续停止热点
            }

            @Override
            public void onStopped() {
                super.onStopped();
                Toast.makeText(MainActivity.this, "热点已停止", Toast.LENGTH_SHORT).show();
                hotspotReservation = null;
            }

            @Override
            public void onFailed(int reason) {
                super.onFailed(reason);
                String errorMsg = switch (reason) {
                    case WifiManager.LocalOnlyHotspotCallback.REASON_BUSY -> "WiFi服务繁忙";
                    case WifiManager.LocalOnlyHotspotCallback.REASON_UNSUPPORTED -> "设备不支持该功能";
                    default -> "启动失败，未知原因";
                };
                Toast.makeText(MainActivity.this, errorMsg, Toast.LENGTH_SHORT).show();
            }
        }, new Handler());
    }

    // 停止热点的方法
    private void stopLocalOnlyHotspot() {
        if (hotspotReservation != null) {
            hotspotReservation.close();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 页面销毁时停止热点
        stopLocalOnlyHotspot();
    }
}

3. 如何连接隐藏热点 #

因为该热点是隐藏的，其他设备无法通过扫描发现，需要手动添加网络：

• 打开另一台设备的WiFi设置
• 选择“添加网络”或“手动输入网络”
• 输入代码中获取到的SSID、密码，加密方式选择WPA2 PSK
• 保存并连接

关键说明 #

• startLocalOnlyHotspot 是Android 8.0（API 26）引入的API，仅支持Android 8.0及以上设备
• 该热点是本地仅用的，无法连接到互联网，仅用于设备间的局域网通信
• 热点会在App进程终止或调用reservation.close()时自动停止

内容的提问来源于stack exchange，提问作者Reaz Ahammed