话不多说，上干货
使用到的库(当前版本)：
//生成二维码的库，可增加logo
qr_flutter: ^3.2.0。
//保存图片用到的库
permission_handler: ^5.0.1+1
image_gallery_saver: ^1.6.6. #（注意android 10 配置位置引用到文件：
import 'dart:async';
import 'dart:io';
import 'dart:typed_data';
import 'dart:ui' as ui;
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:image_gallery_saver/image_gallery_saver.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:qr_flutter/qr_flutter.dart';
import 'package:share/share.dart';
关键方法：
生成图片文件方法
Future _shareUiImage(ui.Image uiImage) async {
ByteData finalByteData = await uiImage.toByteData(format: ImageByteFormat.png);
Uint8List finalPngBytes = finalByteData.buffer.asUint8List();
final document = await getApplicationDocumentsDirectory();
final dir = Directory(document.path +'/Yelana_QR.png');
final imageFile = File(dir.path);
await imageFile.writeAsBytes(finalPngBytes);
return imageFile;
}
生成图片API
GlobalKey globalKey = GlobalKey();
RepaintBoundary（
key: globalKey,
child: Container(需要截图的部分)
）
生成图片
RenderRepaintBoundary boundary = buildContext.findRenderObject();
ui.Image image = await boundary.toImage();
保存图片方法
//检查是否有存储权限
var status = await Permission.storage.status;
if (!status.isGranted) {
status = await Permission.storage.request();
print(status);
return;}
BuildContext buildContext = globalKey.currentContext;
if (null != buildContext){
RenderRepaintBoundary boundary = buildContext.findRenderObject();
ui.Image image = await boundary.toImage();
ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
//图片质量可以根据qulity设置，100为不压缩；
final result = await ImageGallerySaver.saveImage(byteData.buffer.asUint8List(),quality:100,name:'Lead_Image'+DateTime.now().toString() );
if (result['isSuccess'].toString()=='true') {
showToast('保存成功');
}else{
showToast('保存失败');
}
}
//*******************分享图片方法*********************
BuildContext buildContext = globalKey.currentContext;
if (null != buildContext){
RenderRepaintBoundary boundary = buildContext.findRenderObject();
ui.Image image = await boundary.toImage();
File imageFile = await _shareUiImage(image);
Share.shareFiles([imageFile.path]);
}
*******************以下是全部代码*********************
******拷走代码，替换UI小部件，功能实现，开启划水模式✌️*********
import 'dart:async';
import 'dart:io';
import 'dart:typed_data';
import 'dart:ui' as ui;
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';
import 'package:image_gallery_saver/image_gallery_saver.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:qr_flutter/qr_flutter.dart';
import 'package:share/share.dart';
import 'package:yelena_qr_demo/components/public_widget.dart';
class AuthQRPage extends StatefulWidget {
@override
_AuthQRPageState createState() => _AuthQRPageState();
}
class _AuthQRPageState extends State {
GlobalKey globalKey = GlobalKey();
String message = 'www.baidu.com';
//嵌入logo至二维码
Future _loadOverlayImage() async {
final completer = Completer();
final byteData = await rootBundle.load('images/yelena_logo.png');
ui.decodeImageFromList(byteData.buffer.asUint8List(), completer.complete);
return completer.future;
}
//生成图片文件
Future _shareUiImage(ui.Image uiImage) async {
ByteData finalByteData = await uiImage.toByteData(format: ImageByteFormat.png);
Uint8List finalPngBytes = finalByteData.buffer.asUint8List();
final document = await getApplicationDocumentsDirectory();
final dir = Directory(document.path +'/Yelena_QR.png');
final imageFile = File(dir.path);
await imageFile.writeAsBytes(finalPngBytes);
return imageFile;
}
@override
Widget build(BuildContext context) {
final qrFutureBuilder = FutureBuilder(
future: _loadOverlayImage(),
builder: (ctx, snapshot) {
final size = 280.0;
if (!snapshot.hasData) {
return Container(width: size, height: size);
}
return CustomPaint(
size: Size.square(size),
painter: QrPainter(
errorCorrectionLevel: QrErrorCorrectLevel.M,
color: Macro.colorPrimary,
data: message,
version: QrVersions.auto,
embeddedImage: snapshot.data,
embeddedImageStyle: QrEmbeddedImageStyle(
size: Size.square(60),
),
),
);
},
);
return Scaffold(
backgroundColor: Macro.colorPrimary,
appBar: AppBar(
title: Text('二维码',style: Macro.textStyleAppBarTitle,),
),
body: Container(
width: double.infinity,
height: double.infinity,
child: Padding(
padding: EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
//生成图片部分
RepaintBoundary(
key: globalKey,
child: Container(
width: 300,
height: 300,
color: Colors.white,
child: Padding(
padding: EdgeInsets.all(16.0),
child: Container(
color: Colors.white,
child: qrFutureBuilder,
),
),
),
),
SizedBox(height: 30,),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
Container(
width: 120,
height: 50,
child: flatButtonWidget(title: '保存',onPressed: () async{
//检查是否有存储权限
var status = await Permission.storage.status;
if (!status.isGranted) {
status = await Permission.storage.request();
print(status);
return;
}
BuildContext buildContext = globalKey.currentContext;
if (null != buildContext){
RenderRepaintBoundary boundary = buildContext.findRenderObject();
ui.Image image = await boundary.toImage();
ByteData byteData = await image.toByteData(format: ui.ImageByteFormat.png);
final result = await ImageGallerySaver.saveImage(byteData.buffer.asUint8List(),quality:100,name: 'Lead_Image'+DateTime.now().toString() );
if (result['isSuccess'].toString()=='true') {
showToast('保存成功');
}else{
showToast('保存失败');
}
}
},),),
Container(
height: 50,
width: 120,
child: flatButtonWidget( title: '分享',onPressed: () async{
BuildContext buildContext = globalKey.currentContext;
if (null != buildContext){
RenderRepaintBoundary boundary = buildContext.findRenderObject();
ui.Image image = await boundary.toImage();
File imageFile = await _shareUiImage(image);
Share.shareFiles([imageFile.path]);
}
},),)
],
),
],
),
),
)
);
}
}
*********希望能点个赞*********谢谢**************