Question

我开始创建一个Android应用程序wifi无线Wifi直接功能。我做同行发现，我喜欢在列表视图中看到同行。

我现在有一个应用程序试图发现对等体并显示列表中的对等体。

但我面临的问题是，这在Android 5设备上运行良好。在这里，我可以看到我的Android 8设备，但不是相反。我在Android 8设备上看不到我的Android 5设备。

我按照这里的步骤操作： https://developer.android.com/training/connect-devices-wirelessly/nsd

并且还发现了这篇帖子：Android O issues with WiFi Peer Discovery，其中说我需要在继续之前询问权限。

我的清单：

<uses-permission
    android:required="true"
    android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission
    android:required="true"
    android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission
    android:required="true"
    android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission
    android:required="true"
    android:name="android.permission.INTERNET"/>

可能是什么问题？如果需要解决问题，我可以提供更多信息吗？

Answer 1

要解决Android 8（Oreo）的上述问题，需要执行两个步骤：
1）授予位置权限。

    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
       requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                     PERMISSIONS_REQUEST_CODE_ACCESS_COARSE_LOCATION);
        //After this point you wait for callback in onRequestPermissionsResult(int, String[], int[]) overriden method

    }else{
       mManager.requestPeers(mChannel, mainActivity.peerListListener);
       //do something, permission was previously granted; or legacy device
    }

2）启用位置服务/打开设备的GPS。
下面的代码打开启用位置对话框。

public static void displayLocationSettingsRequest(final Context context, final int REQUEST_CHECK_SETTINGS) {
    GoogleApiClient googleApiClient = new GoogleApiClient.Builder(context)
            .addApi(LocationServices.API).build();
    googleApiClient.connect();

    LocationRequest locationRequest = LocationRequest.create();
    locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    locationRequest.setInterval(10000);
    locationRequest.setFastestInterval(10000 / 2);

    LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder().addLocationRequest(locationRequest);
    builder.setAlwaysShow(true);

    Task<LocationSettingsResponse> result = LocationServices.getSettingsClient(context).checkLocationSettings(builder.build());
    result.addOnCompleteListener(new OnCompleteListener<LocationSettingsResponse>() {
        @Override
        public void onComplete(@NonNull Task<LocationSettingsResponse> task) {
            LocationSettingsResponse response = null;
            try {
                response = task.getResult(ApiException.class);
            } catch (ApiException exception) {
                exception.printStackTrace();

                switch (exception.getStatusCode()) {
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the
                        // user a dialog.
                        try {
                            // Cast to a resolvable exception.
                            ResolvableApiException resolvable = (ResolvableApiException) exception;
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            resolvable.startResolutionForResult((MainActivity)context, REQUEST_CHECK_SETTINGS);
                            break;
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        } catch (ClassCastException e) {
                            // Ignore, should be an impossible error.
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way to fix the
                        // settings so we won't show the dialog.

                        break;
                }
            }

        }
    });

Answer 2

我通过添加运行时权限对其进行了修复...

Manifest.permission.ACCESS_COARSE_LOCATION

允许，一切正常

Answer 3

只需打开定位，它对我有用

Android - Wifi Direct / p2p无法在Android 8

3 个答案: