如果 targetSdkVersion >= 26，WifiManager.WifiInfo getSSID & getBSSID 不起作用

Question

如果我使用 API 27 编译但目标 API 25，我将正确获取这些值。如果我将 targetSdkVersion 设置为 27，那么这些值将无法正确检索。

以 SDK 25 或更低为目标，值正确，但以 26 或更高为目标，我得到了这些值：

SSID 给<unknown ssid>

BBSSID 给02:00:00:00:00:00

这些是我的清单权限，都是普通权限，不需要用户授权：

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

这是示例代码：

WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
WifiInfo connectionInfo = wifiManager.getConnectionInfo();
connectionInfo.getSSID();
connectionInfo.getBSSID();

针对 SDK 26 或更高版本时发生了什么变化？我们还应该做些什么来获得这些值？

Answer 1

您需要从 API 27 开始的位置权限

Answer 2

Google 已更改其对 WifiManager 的政策，因为您可以从 SDK 跟踪用户的位置跟踪 wifi 位置>=27。因此，您需要访问位置权限才能将 getSSID() 用于您的应用程序。 为了使用此代码，请按照以下说明操作。

正如@Samuel Eminet 上面的回答，您需要 ACCESS_FINE_LOCATION 或 ACCESS_COARSE_LOCATION。我使用 ACCESS_FINE_LOCATION 因为 ACCESS_COARSE_LOCATION 请求仅 NETWORK_PROVIDE 的权限，而 ACCESS_FINE_LOCATION 请求 NETWORK_PROVIDE 和 GPS_PROVIDER 的权限。

Refer here for more information

在您的清单文件中

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

以及您的 wifi 管理器所在的位置，添加此代码以请求权限。

 if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED){

        //Permission Not Granted
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSION_FINE_LOCATION);
    }



    @Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {                                   
        switch (requestCode) {

        case PERMISSION_FINE_LOCATION:
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //permission granted keep going status
                Log.d(TAG, "PERMISSION GRANTED");
            }
            else {
                Log.d(TAG, "PERMISSION DENIED");
            }
    }
}

Answer 3

还有一件事要记住（我学得很辛苦）。如果您将应用程序侧加载到设备上，请不要忘记在应用程序权限（长按应用程序、应用程序信息）中“允许”位置权限。默认情况下它是关闭的，因此您将获得

Answer 4

我遇到了同样的问题。这个问题发生在比 API 23 更高的 android 版本上。 解决方案： 您需要在 build.gradle 文件中添加以下内容。

implementation 'com.google.android.gms:play-services-location:15.0.0'

并且您允许遵守规则。

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION">

以下代码自动提供应用程序中的位置权限。

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        try {
            LocationRequest request = new LocationRequest()
                    .setFastestInterval(1500)
                    .setInterval(3000)
                    .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

            builder = new LocationSettingsRequest.Builder()
                    .addLocationRequest(request);

            try {
                Task<LocationSettingsResponse> result =
                        LocationServices.getSettingsClient(this.getApplicationContext()).checkLocationSettings(builder.build());
                result.addOnCompleteListener(new OnCompleteListener<LocationSettingsResponse>() {
                    @Override
                    public void onComplete(@NonNull Task<LocationSettingsResponse> task) {
                        try {
                            task.getResult(ApiException.class);
                        } catch (ApiException e) {
                            switch (e.getStatusCode()) {
                                case LocationSettingsStatusCodes
                                        .RESOLUTION_REQUIRED:
                                    ResolvableApiException resolveApiException = (ResolvableApiException) e;
                                    try {
                                        resolveApiException.startResolutionForResult(WifiConnectionActivity.this, REQUEST_CHECK_CODE);
                                    } catch (IntentSender.SendIntentException ex) {
                                        ex.printStackTrace();
                                    } catch (ClassCastException ex) {

                                    }
                                    break;

                                case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                                    break;
                            }
                        }
                    }
                });
            } catch (Exception x) {
            }
            checkPermissions();
        } catch (Exception a) {
        }
    }


void checkPermissions() {
    if(ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) !=
            PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(WifiConnectionActivity.this, new String[]
                {
                        Manifest.permission.ACCESS_COARSE_LOCATION
                }, REQUEST_LOCATION);
    }
    else{
        //Toast.makeText(getActivity(), "GPS is already permissioned", Toast.LENGTH_SHORT).show();
    }
}

Answer 5

下面是代码。

public String getMac() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        //Permission Not Granted
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
    }else{
        WifiManager wifimanage = (WifiManager) getApplicationContext().getSystemService(WIFI_SERVICE);
        WifiInfo wifiinfo = wifimanage.getConnectionInfo();
        macAddress = wifiinfo.getBSSID();//Get the mac address of the currently connected network;
    }
    return macAddress;
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case 1:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //permission granted keep going status
                Log.d("mac", "PERMISSION GRANTED");
                WifiManager wifimanage = (WifiManager) getApplicationContext().getSystemService(WIFI_SERVICE);
                WifiInfo wifiinfo = wifimanage.getConnectionInfo();
                macAddress = wifiinfo.getBSSID();//Get the mac address of the currently connected network;
            } else {
                Log.d("mac", "PERMISSION DENIED");
            }
    }
}

然后调用 getMac() 解决问题。