Flutter新手教程：如何在Windows系统下，用Flutter做自定义区域的屏幕截图？

flutter 屏幕截图，超出屏幕截图

用于flutter 自定义截图，超出屏幕的部分也可以截取到

import'dart:io';import'dart:typed_data';import'dart:ui';import'package:flutter/material.dart';import'package:flutter/rendering.dart';classScreenShotPageextendsStatefulWidget{
  @override
  _ScreenShotPageState createState()=>_ScreenShotPageState();}class_ScreenShotPageStateextendsState<ScreenShotPage>{
  GlobalKey _rootWidgetKey =GlobalKey();
  @override
  Widget build(BuildContext context){returnMaterial(
      child:Scaffold(
        appBar:AppBar(title:Text('屏幕截图')),
        body:SafeArea(
          child:Stack(
            children:<Widget>[Positioned(
                left:0,
                right:0,
                top:0,
                bottom:60,
                child:SingleChildScrollView(
                    scrollDirection: Axis.vertical,
                    child:RepaintBoundary(
                      key: _rootWidgetKey,
                      child:Container(
                        width: double.infinity,
                        color:Color(0xffe8eaed),
                        child:Column(children:<Widget>[Column(children:_listWidget())]),),)),),Positioned(left:0, right:0, bottom:0, height:60, child:_bottomWidget()),],),),),);}///数组
  List<Widget>_listWidget(){
    List<Widget> _list =List();for(int index =0; index <20; index++){
      _list.add(Container(height:30, child:Center(child:Text('屏幕截图$index'))));}return _list;}///bottomWidget
  Widget _bottomWidget(){returnContainer(
      padding: EdgeInsets.fromLTRB(16,0,16,0),
      height:60,
      color: Colors.black.withOpacity(0.8),
      child:Center(
        child:RaisedButton(
          color: Colors.blue,
          shape:RoundedRectangleBorder(borderRadius: BorderRadius.circular(28)),
          onPressed:(){// showLoading(msg: '图片生成中...');_screenshotImg();},
          child:Text('完成', style:TextStyle(fontSize:16, color: Colors.white)),),),);}///截图
  Future _screenshotImg()async{try{
      RenderRepaintBoundary boundary = _rootWidgetKey.currentContext.findRenderObject();var _dpr = window.devicePixelRatio;var image =await boundary.toImage(pixelRatio: _dpr);_getImgFilePath(image,'root/filePath').then((filePath){print('filePath:$filePath');});}catch(e){print(e);}}/// 图片写入Filestatic Future<String>_getImgFilePath(var image, String filePath)async{
    ByteData byteData =await image.toByteData(format: ImageByteFormat.png);
    Uint8List pngBytes = byteData.buffer.asUint8List();
    File file =File('$filePath/237128773298739.png');if(!file.existsSync()){
      file.createSync();}
    file.writeAsBytesSync(pngBytes);return file.path;}}