How to set lockscreen wallpaper using flutter?

i am also having the similar issue but i am developing my app using flutter. with my code i am able to change home screen wallpaper but it does not work for set lock screen or set both.

Another problem is also there ....i am able to set homescreen wallpaper on android api level 24 and above

MainActivity CODE:

 package com.eabesh.wallpaper_app
 import android.os.Bundle
 import io.flutter.app.FlutterActivity
 import io.flutter.plugin.common.MethodChannel
 import java.io.IOException
 import android.app.WallpaperManager
 import android.graphics.BitmapFactory
 import android.os.Build
 import android.annotation.TargetApi
 import android.content.Context
 import io.flutter.plugins.GeneratedPluginRegistrant

   private const val CHANNEL = "com.eabesh.wallpaperapp/wallpapers"
    class MainActivity: FlutterActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    GeneratedPluginRegistrant.registerWith(this)

    MethodChannel(flutterView, CHANNEL).setMethodCallHandler { call, result ->
        if (call.method == "setWallpaper") {
            val arguments = call.arguments as ArrayList<*>
            val setWallpaper = setWallpaper(arguments[0] as String, applicationContext, arguments[1] as Int)

            if (setWallpaper == 0) {
                result.success(setWallpaper)
            } else {
                result.error("UNAVAILABLE", "", null)
            }
        } else {
            result.notImplemented()
        }
    }
}
@TargetApi(24)
private fun setWallpaper(path: String, applicationContext: Context, wallpaperType: Int): Int {
    var setWallpaper=1
    val bitmap = BitmapFactory.decodeFile(path)
    val wm: WallpaperManager? = WallpaperManager.getInstance(applicationContext)
    setWallpaper = try {
        wm?.setBitmap(bitmap, null, true, wallpaperType)
        0
    } catch (e: IOException) {
        1
    }

    return setWallpaper
    }
 }

fullScreen Code:

import 'package:flutter/material.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/painting.dart';
import 'package:photo_view/photo_view.dart';
import 'package:fluttertoast/fluttertoast.dart';
import 'package:flutter/services.dart';
import 'package:image_downloader/image_downloader.dart';
import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'dart:async';
import 'package:path_provider/path_provider.dart';
import 'package:dio/dio.dart';
import 'dart:io' as Io;




 class FullScreenImagePage extends StatefulWidget {
    final String imgPath;
    final String imgName;

    FullScreenImagePage(this.imgPath,this.imgName);

    @override
    _FullScreenImagePageState createState() => _FullScreenImagePageState();
        }

      class _FullScreenImagePageState extends State<FullScreenImagePage> {
      static const platform = const 
      MethodChannel('com.eabesh.wallpaperapp/wallpapers');
       bool permission = false;
         bool downloading = false;
         var progress = '';
         var _progresss;
          String _batteryLevel = 'Unknown battery level.';

          @override
           void initState() {
              // TODO: implement initState
                     super.initState();
                  //getPermission();
                  ImageDownloader.callback(onProgressUpdate: (String imageId, int 
                 progress) {
             setState(() {
                 _progresss = progress;
            print('>>>>>>>>>>>>>>>>>>$_progresss');
                });
             });
          }

         final LinearGradient backgroundGradient = new LinearGradient(
             colors: [new Color(0x10000000), new Color(0x30000000)],
            begin: Alignment.topLeft,
             end: Alignment.bottomRight);

           void toastFunction(context, message) {
          //Toast.show("Double Tap to Zoom",context, duration: Toast.LENGTH_SHORT, 
           gravity:  Toast.BOTTOM);
           Fluttertoast.showToast(
           msg: "$message",
             toastLength: Toast.LENGTH_SHORT,
             gravity: ToastGravity.BOTTOM,
            timeInSecForIos: 1,
            textColor: Colors.white,
             fontSize: 16.0);
           }

           IconData changeIcon() {
          if (_progresss == 100) {
             setState(() {
           return Icons.done;
             });
              } else {
                setState(() {
               return Icons.arrow_downward;
             });
             }
           return Icons.arrow_downward;
             }

         @override
          Widget build(BuildContext context) {
             double height = MediaQuery
            .of(context)
            .size
             .height;
            double width = MediaQuery
           .of(context)
            .size
              .width;
           //toastFunction(context, 'Double tap to Zoom');

return new Scaffold(
  body: new SizedBox.expand(
    child: new Container(
      decoration: new BoxDecoration(gradient: backgroundGradient),
      child: new Stack(
        children: <Widget>[
          new Align(
            alignment: Alignment.center,
            child: PhotoView(
              imageProvider: CachedNetworkImageProvider(widget.imgPath),
              loadingChild: CircularProgressIndicator(),
              //childSize: Size(width, height),
              //initialScale: PhotoViewComputedScale.covered*height,
              minScale: PhotoViewComputedScale.contained * 0.8,
              maxScale: PhotoViewComputedScale.covered * 1.8,
              heroAttributes: PhotoViewHeroAttributes(tag: widget.imgPath),
              //initialScale: height,
            ),
          ),
          GestureDetector(
            onTap: () {
              Navigator.of(context).pop();
            },
            child: new Align(
                alignment: Alignment.bottomRight,
                child: Container(
                  margin: EdgeInsets.all(20),
                  padding: EdgeInsets.all(10),
                  decoration: BoxDecoration(
                      borderRadius: BorderRadius.circular(100),
                      border: Border.all(width: 2, color: Colors.white)),
                  child: Icon(
                    Icons.cancel,
                    color: Colors.white,
                  ),
                )),
          ),
          GestureDetector(
            onTap: () async {
              try {
                toastFunction(context, 'Image Downloading In Background');
                var imageId = await ImageDownloader.downloadImage(
                  widget.imgPath,
                  destination: AndroidDestinationType.custom()
                    ..subDirectory("Hd walls/image.jpeg"),
                );
              } catch (e) {
                print(e);
              }
            },
            child: new Align(
                alignment: Alignment.bottomCenter,
                child: Container(
                  margin: EdgeInsets.all(20),
                  padding: EdgeInsets.all(10),
                  decoration: BoxDecoration(
                      borderRadius: BorderRadius.circular(100),
                      border: Border.all(width: 2, color: Colors.white)),
                  child: Icon(
                    (_progresss != 100) ? Icons.arrow_downward : Icons.done,
                    color: Colors.white,
                  ),
                )),
          ),
          new Align(
            alignment: Alignment.bottomLeft,
            child: GestureDetector(
              onTap: () {
                setWallpaperDialog();

                ///_getBatteryLevel();
              },
              child: Container(
                margin: EdgeInsets.all(20),
                padding: EdgeInsets.all(10),
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(100),
                    border: Border.all(width: 2, color: Colors.white)),
                child: Icon(
                  Icons.image,
                  color: Colors.white,
                ),
              ),
            ),
          )
        ],
      ),
    ),
  ),
);
         }

              //function for the setting wallpaper in android;
             void setWallpaperDialog() {
           showDialog(
              context: context,
              builder: (context) {
    return Dialog(
      backgroundColor: Colors.white,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.all(16.0),
            child: Text(
              'Set a wallpaper',
              style: TextStyle(
                fontSize: 20.0,
                fontWeight: FontWeight.bold,
                color: Colors.black,
              ),
            ),
          ),
          ListTile(
            title: Text(
              'Home Screen',
              style: TextStyle(color: Colors.black),
            ),
            leading: Icon(
              Icons.home,
              color: Colors.black,
            ),
            onTap: () => _setWallpaper(1),
          ),
          ListTile(
            title: Text(
              'Lock Screen',
              style: TextStyle(color: Colors.black),
            ),
            leading: Icon(
              Icons.lock,
              color: Colors.black,
            ),
            onTap: () => _setWallpaper(2),
          ),
          ListTile(
            title: Text(
              'Both',
              style: TextStyle(color: Colors.black),
            ),
            leading: Icon(
              Icons.phone_android,
              color: Colors.black,
            ),
            onTap: () => _setWallpaper(3),
          ),
        ],
      ),
    );
  },
);
     }

    Future<void> _setWallpaper(int wallpaperType) async {
    var file =
    await DefaultCacheManager().getSingleFile(widget.imgPath);
     try {
         final int result = await platform
            .invokeMethod(
            'setWallpaper',[file.path,wallpaperType]);
              print('Wallpaper Updated.... $result');
           } on PlatformException catch (e) {
             print("Failed to Set Wallpaper: '${e.message}'.");
          }
        Fluttertoast.showToast(
         msg: "Wallpaper set successfully",
         toastLength: Toast.LENGTH_SHORT,
         gravity: ToastGravity.CENTER,
         timeInSecForIos: 1,
         backgroundColor: Colors.white,
         textColor: Colors.black,
         fontSize: 16.0);
         Navigator.pop(context);
         }
         Future<void> _getBatteryLevel() async {
         String batteryLevel;
          try {
          final int result = await platform.invokeMethod(
           'getBatteryLevel', {"path": "fuck bo"});
           batteryLevel = 'Battery level at $result % .';
           } on PlatformException catch (e) {
           batteryLevel = "Failed to get battery level: '${e.message}'.";
          }

           setState(() {
          _batteryLevel = batteryLevel;
          print(
                  '>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 
                      <<<<<<<<<<<<<<>$_batteryLevel');
          });
         }
         }