前言

RepaintBoundary作为flutter截屏控件，截屏内容无法截取到带有播放器的播放内容页面，所以考虑调用安卓原生的截屏

插件目录结构

在这里插入图片描述

package net.bengkelrobot.flutter_native_screenshot;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.util.Log;
import android.view.View;

import androidx.annotation.NonNull;

import java.io.File;
import java.io.FileOutputStream;
import java.util.Date;

import io.flutter.embedding.engine.plugins.FlutterPlugin;
import io.flutter.embedding.engine.plugins.activity.ActivityAware;
import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
import io.flutter.embedding.engine.renderer.FlutterRenderer;
import io.flutter.plugin.common.BinaryMessenger;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;
import io.flutter.plugin.common.PluginRegistry.Registrar;
import io.flutter.view.FlutterView;

/**
 * FlutterNativeScreenshotPlugin
 */
public class FlutterNativeScreenshotPlugin
        implements FlutterPlugin, MethodCallHandler, ActivityAware {
    private static final String TAG = "FNSPlugin";
    //声明context对象
    private Context context;
    //声明channel
    private MethodChannel channel;
    //声明context对象
    private Activity activity;
    //声明context对象
    private Object renderer;
    //声明状态
    private boolean ssError = false;
    //声明图片的路径
    private String ssPath;

    // Default constructor for old registrar
    public FlutterNativeScreenshotPlugin() {
    } // FlutterNativeScreenshotPlugin()

    // Condensed logic to initialize the plugin
    private void initPlugin(Context context, BinaryMessenger messenger, Activity activity,
                            Object renderer) {
        this.context = context;
        this.activity = activity;
        this.renderer = renderer;

        this.channel = new MethodChannel(messenger, "flutter_native_screenshot");
        this.channel.setMethodCallHandler(this);
    } // initPlugin()

    //**************************注册插件******************************************
    @Override
    public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBinding) {
        Log.println(Log.INFO, TAG, "Using *NEW* registrar method!");

        initPlugin(
                flutterPluginBinding.getApplicationContext(),
                flutterPluginBinding.getBinaryMessenger(),
                null,
                flutterPluginBinding.getFlutterEngine().getRenderer()
        ); // initPlugin()
    } // onAttachedToEngine()

    // New v2 listener methods
    @Override
    public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
        this.channel.setMethodCallHandler(null);
        this.channel = null;
        this.context = null;
    } // onDetachedFromEngine()

    //旧的注册方法
    //插件仍应包含静态的 registerWith() 方法，
    //与不使用 v2 embedding 的应用程序保持兼容。
    public static void registerWith(Registrar registrar) {
        Log.println(Log.INFO, TAG, "Using *OLD* registrar method!");

        FlutterNativeScreenshotPlugin instance = new FlutterNativeScreenshotPlugin();

        instance.initPlugin(
                registrar.context(),
                registrar.messenger(),
                registrar.activity(),
                registrar.view()
        ); // initPlugin()
    } // registerWith()

    //***************************************在插件中引入activity对象***************
    // Activity condensed methods
    private void attachActivity(ActivityPluginBinding binding) {
        //获取当前flutter页面所处的Activity.
        this.activity = binding.getActivity();
    } // attachActivity()

    private void detachActivity() {
        this.activity = null;
    } // attachActivity()


    // Activity listener methods
    @Override
    public void onAttachedToActivity(ActivityPluginBinding binding) {
        attachActivity(binding);
    } // onAttachedToActivity()

    @Override
    public void onDetachedFromActivityForConfigChanges() {
        detachActivity();
    } // onDetachedFromActivityForConfigChanges()

    @Override
    public void onReattachedToActivityForConfigChanges(ActivityPluginBinding binding) {
        attachActivity(binding);
    } // onReattachedToActivityForConfigChanges()

    @Override
    public void onDetachedFromActivity() {
        detachActivity();
    } // onDetachedFromActivity()


    //************************方法回调，这里主要是回调管道调用的方法***************************
    @Override
    public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
        if (!call.method.equals("takeScreenshot")) {
            Log.println(Log.ERROR, TAG, "Method not implemented!");
            result.notImplemented();
            return;
        }
        takeScreenshotOld();
        result.success(ssPath);

    } // onMethodCall()

    //*************************封装自己的方法*************************************
    //用当前时间命名图片
    private String getScreenshotName() {
        java.text.SimpleDateFormat sf = new java.text.SimpleDateFormat("yyyyMMddHHmmss");
        String sDate = sf.format(new Date());

        return "flutter_native_screenshot-" + sDate + ".png";
    } // getScreenshotName()

    //获取
    private String getScreenshotPath() {
        String pathTemporary = context.getCacheDir().getPath();
        Log.println(Log.INFO, TAG, "path temporary: " + pathTemporary);

        String dirPath = pathTemporary + "/" + getScreenshotName();

        Log.println(Log.INFO, TAG, "Built ScreeshotPath: " + dirPath);

        return dirPath;
    } // getScreenshotPath()

    private String writeBitmap(Bitmap bitmap) {
        try {
            String path = getScreenshotPath();
            File imageFile = new File(path);
            FileOutputStream oStream = new FileOutputStream(imageFile);

            bitmap.compress(Bitmap.CompressFormat.PNG, 100, oStream);
            oStream.flush();
            oStream.close();

            return path;
        } catch (Exception ex) {
            Log.println(Log.INFO, TAG, "Error writing bitmap: " + ex.getMessage());
        }

        return null;
    } // writeBitmap()

    private void reloadMedia() {
        try {
            //扫描媒体文件
            Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
            File file = new File(this.ssPath);
            Uri uri = Uri.fromFile(file);

            intent.setData(uri);
            this.activity.sendBroadcast(intent);
        } catch (Exception ex) {
            Log.println(Log.INFO, TAG, "Error reloading media lib: " + ex.getMessage());
        }
    } // reloadMedia()

    private void takeScreenshotOld() {
        Log.println(Log.INFO, TAG, "Trying to take screenshot [old way]");

        try {
            //使用getWindow().getDecorView().getRootView()是获取当前屏幕的activity
            View view = this.activity.getWindow().getDecorView().getRootView();
            //从ImageView对象获取图像之前
            view.setDrawingCacheEnabled(true);

            Bitmap bitmap = null;
            if (this.renderer.getClass() == FlutterView.class) {
                bitmap = ((FlutterView) this.renderer).getBitmap();
            } else if (this.renderer.getClass() == FlutterRenderer.class) {
                bitmap = ((FlutterRenderer) this.renderer).getBitmap();
            }

            if (bitmap == null) {
                this.ssError = true;
                this.ssPath = null;

                Log.println(Log.INFO, TAG, "The bitmap cannot be created :(");

                return;
            } // if
            //从ImageView对象获取图像之后
            view.setDrawingCacheEnabled(false);
            //这样才能以清空画图缓冲区否则会导致下次还是上次的图
            String path = writeBitmap(bitmap);
            if (path == null || path.isEmpty()) {
                this.ssError = true;
                this.ssPath = null;

                Log.println(Log.INFO, TAG, "The bitmap cannot be written, invalid path.");

                return;
            } // if

            this.ssError = false;
            this.ssPath = path;

            reloadMedia();
        } catch (Exception ex) {
            Log.println(Log.INFO, TAG, "Error taking screenshot: " + ex.getMessage());
        }
    } // takeScreenshot()
}

AndroidManifest.xml的配置

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="net.bengkelrobot.flutter_native_screenshot">
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>

在lib封装

import 'dart:async';

import 'package:flutter/services.dart';

/// Class to capture screenshots with native code working on background
class FlutterNativeScreenshot {
  static const MethodChannel _channel = const MethodChannel('flutter_native_screenshot');

  /// Captures everything as is shown in user's device.
  ///
  /// Returns [null] if an error occurs.
  /// Returns a [String] with the path of the screenshot.
  static Future<String> takeScreenshot() async {
    final String path = await _channel.invokeMethod('takeScreenshot');
    return path;
  }
}

总结

可用，简单
调用方法
import之后
String path = await FlutterNativeScreenshot .takeScreenshot();

如果还需要做后续处理比如说将文件数据读取出来
可以作为image，或者盒子背景或者通过dio上传到网上

//提醒一下：这里的widget.picturePath实际上是上述的path
      File _dataFile = File(widget.picturePath);
      Uint8List _screenImgData = await _dataFile.readAsBytesSync();
      //在widget那里可以通过
      Image.memory(_screenImgData);
      //或者作为盒子的背景
      Container(
         // decoration: BoxDecoration(color: Colors.white),
         decoration: BoxDecoration(
             image: DecorationImage(
                 image: MemoryImage(
                   _screenImgData,
                 ),
                 fit: BoxFit.fill)),
       )
       //或者上传(这里的 NetUtils.postFormData实际上是对dio进行了一层封装）
       NetUtils.postFormData(
              Api.saveOrshareImg,
              {"file": await MultipartFile.fromFile(widget.picturePath, filename: 'save.png')},
              success: (response) {
                print(response);
                var jsonData = json.decode(response);
                var res = ResponseModel.fromJson(jsonData);
                if (res.status == 0) {;
                  print('success');
                  // }
                } else {
                  print("${res.info.detail}${res.info.message}");
                }
              },
              fail: (e) {
                print(e.toString());
              },
            );

最开始命令行创建
flutter create --org com.example --template=plugin --platforms=android,ios -a java 插件名字