Dart 如何在flatter中拍摄屏幕以外的小部件截图？
我正在使用重新绘制边界拍摄当前小部件的屏幕截图，它是一个列表视图。但它只捕获当时在屏幕上可见的内容Dart 如何在flatter中拍摄屏幕以外的小部件截图？,dart,flutter,screenshot,Dart,Flutter,Screenshot,我正在使用重新绘制边界拍摄当前小部件的屏幕截图，它是一个列表视图。但它只捕获当时在屏幕上可见的内容 RepaintBoundary( key: src, child: ListView(padding: EdgeInsets.only(left: 10.0), scrollDirection: Axis.horizontal, children: <Wid
RepaintBoundary(
key: src,
child: ListView(padding: EdgeInsets.only(left: 10.0),
scrollDirection: Axis.horizontal,
children: <Widget>[
Align(
alignment: Alignment(-0.8, -0.2),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: listLabel(orientation),
)
),
Padding(padding: EdgeInsets.all(5.0)),
Align(
alignment: FractionalOffset(0.3, 0.5),
child: Container(
height: orientation == Orientation.portrait? 430.0: 430.0*0.7,
decoration: BoxDecoration(
border: Border(left: BorderSide(color: Colors.black))
),
//width: 300.0,
child:
Wrap(
direction: Axis.vertical,
//runSpacing: 10.0,
children: colWidget(orientation),
)
)
),
Padding(padding: EdgeInsets.all(5.0)),
Column(
mainAxisAlignment: MainAxisAlignment.center,
children: listLabel(orientation),
)
],
),
);
是否有任何方法可以捕获整个listView，即不仅捕获屏幕上不可见的内容，还捕获可滚动的内容。或者，如果整个小部件太大，无法放在一张图片中，它可以在多张图片中捕获。这让我好奇这是否可能，所以我制作了一个快速的模型，显示它确实有效。但请注意，这样做实际上是故意破坏了flutter为优化所做的工作，因此，您真的不应该超出您绝对需要的范围使用它 不管怎样，代码如下：
import 'dart:math';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
void main() => runApp(MyApp());
class UiImagePainter extends CustomPainter {
final ui.Image image;
UiImagePainter(this.image);
@override
void paint(ui.Canvas canvas, ui.Size size) {
// simple aspect fit for the image
var hr = size.height / image.height;
var wr = size.width / image.width;
double ratio;
double translateX;
double translateY;
if (hr < wr) {
ratio = hr;
translateX = (size.width - (ratio * image.width)) / 2;
translateY = 0.0;
} else {
ratio = wr;
translateX = 0.0;
translateY = (size.height - (ratio * image.height)) / 2;
}
canvas.translate(translateX, translateY);
canvas.scale(ratio, ratio);
canvas.drawImage(image, new Offset(0.0, 0.0), new Paint());
}
@override
bool shouldRepaint(UiImagePainter other) {
return other.image != image;
}
}
class UiImageDrawer extends StatelessWidget {
final ui.Image image;
const UiImageDrawer({Key key, this.image}) : super(key: key);
@override
Widget build(BuildContext context) {
return CustomPaint(
size: Size.infinite,
painter: UiImagePainter(image),
);
}
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
GlobalKey<OverRepaintBoundaryState> globalKey = GlobalKey();
ui.Image image;
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(),
body: image == null
? Capturer(
overRepaintKey: globalKey,
)
: UiImageDrawer(image: image),
floatingActionButton: image == null
? FloatingActionButton(
child: Icon(Icons.camera),
onPressed: () async {
var renderObject = globalKey.currentContext.findRenderObject();
RenderRepaintBoundary boundary = renderObject;
ui.Image captureImage = await boundary.toImage();
setState(() => image = captureImage);
},
)
: FloatingActionButton(
onPressed: () => setState(() => image = null),
child: Icon(Icons.remove),
),
),
);
}
}
class Capturer extends StatelessWidget {
static final Random random = Random();
final GlobalKey<OverRepaintBoundaryState> overRepaintKey;
const Capturer({Key key, this.overRepaintKey}) : super(key: key);
@override
Widget build(BuildContext context) {
return SingleChildScrollView(
child: OverRepaintBoundary(
key: overRepaintKey,
child: RepaintBoundary(
child: Column(
children: List.generate(
30,
(i) => Container(
color: Color.fromRGBO(random.nextInt(256), random.nextInt(256), random.nextInt(256), 1.0),
height: 100,
),
),
),
),
),
);
}
}
class OverRepaintBoundary extends StatefulWidget {
final Widget child;
const OverRepaintBoundary({Key key, this.child}) : super(key: key);
@override
OverRepaintBoundaryState createState() => OverRepaintBoundaryState();
}
class OverRepaintBoundaryState extends State<OverRepaintBoundary> {
@override
Widget build(BuildContext context) {
return widget.child;
}
}
import'dart:math'；
将“dart:ui”导入为ui；
进口“包装：颤振/材料.省道”；
导入“package:flatter/rendering.dart”；
void main（）=>runApp（MyApp（））；
类UiImagePainter扩展了CustomPainter{
最终用户界面。图像；
UiImagePainter（this.image）；
@凌驾
虚空绘制（ui.Canvas画布，ui.Size）{
//适合图像的简单方面
var hr=size.height/image.height；
var wr=size.width/image.width；
双倍比率；
双translateX；
双重翻译；
如果（hr\u MyAppState（）；
}
类MyAppState扩展了状态{
GlobalKey GlobalKey=GlobalKey（）；
ui.图像；
@凌驾
小部件构建（构建上下文）{
返回材料PP(
家：脚手架(
appBar:appBar（），
正文：image==null
？捕获者(
过密键：globalKey，
)
：UiImageDrawer（图像：图像），
floatingActionButton:image==null
？浮动操作按钮(
子：图标（图标.摄像机），
onPressed:（）异步{
var renderObject=globalKey.currentContext.FindEnderObject（）；
RenderPaintBoundary=renderObject；
ui.Image captureImage=wait boundary.toImage（）；
设置状态（（）=>image=captureImage）；
},
)
：浮动操作按钮(
按下时：（）=>setState（（）=>image=null），
子：图标（图标。删除），
),
),
);
}
}
类捕获器扩展了无状态小部件{
静态最终随机=随机（）；
最终GlobalKey OverrepaitKey；
constcapturer（{Key-Key，this.overrepaitkey}）：super（Key:Key）；
@凌驾
小部件构建（构建上下文）{
返回SingleChildScrollView(
孩子：越过边界(
钥匙：修理过度钥匙，
子：重新绘制边界(
子：列(
子项：List.generate(
30,
（i） =>容器(
颜色：color.fromRGBO（random.nextInt（256），random.nextInt（256），random.nextInt（256），1.0），
身高：100，
),
),
),
),
),
);
}
}
类覆盖边界扩展StatefulWidget{
最后一个孩子；
const oversepaintboundary（{Key-Key，this.child}）：super（Key:Key）；
@凌驾
OverRepaintBoundaryState createState（）=>OverRepaintBoundaryState（）；
}
类OverRepaintBoundaryState扩展状态{
@凌驾
小部件构建（构建上下文）{
返回widget.child；
}
}
请特别注意“overRepaintKey”和OverRepaintBoundary。通过迭代渲染子对象，您可能不需要使用它，但这使它变得容易得多 我使用这个软件包实现了这个问题的解决方案：，它拍摄了整个小部件的屏幕截图。这很简单，按照PubDev或GitHub上的步骤进行操作，您就可以让它工作了 OBS：要获取小部件的完整屏幕截图，请确保您的小部件是完全可滚动的，而不仅仅是其中的一部分 （在我的例子中，我在一个容器中有一个ListView，而这个包并没有截取所有ListView的屏幕截图，因为它上面有很多iTen，所以我将我的容器包装在一个SingleChildScrollView中，并在ListView中添加NeverScrollableScrollPhysics，它可以工作！：D）。 有一个简单的方法 您需要wrapSingleChildScrollView小部件来重新绘制边界。只需使用SingleChildScrollView包装您的可滚动小部件（或其父亲）
SingleChildScrollView(
子：重新绘制边界(
键：_globalKey
)
)
import 'dart:math';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
void main() => runApp(MyApp());
class UiImagePainter extends CustomPainter {
final ui.Image image;
UiImagePainter(this.image);
@override
void paint(ui.Canvas canvas, ui.Size size) {
// simple aspect fit for the image
var hr = size.height / image.height;
var wr = size.width / image.width;
double ratio;
double translateX;
double translateY;
if (hr < wr) {
ratio = hr;
translateX = (size.width - (ratio * image.width)) / 2;
translateY = 0.0;
} else {
ratio = wr;
translateX = 0.0;
translateY = (size.height - (ratio * image.height)) / 2;
}
canvas.translate(translateX, translateY);
canvas.scale(ratio, ratio);
canvas.drawImage(image, new Offset(0.0, 0.0), new Paint());
}
@override
bool shouldRepaint(UiImagePainter other) {
return other.image != image;
}
}
class UiImageDrawer extends StatelessWidget {
final ui.Image image;
const UiImageDrawer({Key key, this.image}) : super(key: key);
@override
Widget build(BuildContext context) {
return CustomPaint(
size: Size.infinite,
painter: UiImagePainter(image),
);
}
}
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
GlobalKey<OverRepaintBoundaryState> globalKey = GlobalKey();
ui.Image image;
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(),
body: image == null
? Capturer(
overRepaintKey: globalKey,
)
: UiImageDrawer(image: image),
floatingActionButton: image == null
? FloatingActionButton(
child: Icon(Icons.camera),
onPressed: () async {
var renderObject = globalKey.currentContext.findRenderObject();
RenderRepaintBoundary boundary = renderObject;
ui.Image captureImage = await boundary.toImage();
setState(() => image = captureImage);
},
)
: FloatingActionButton(
onPressed: () => setState(() => image = null),
child: Icon(Icons.remove),
),
),
);
}
}
class Capturer extends StatelessWidget {
static final Random random = Random();
final GlobalKey<OverRepaintBoundaryState> overRepaintKey;
const Capturer({Key key, this.overRepaintKey}) : super(key: key);
@override
Widget build(BuildContext context) {
return SingleChildScrollView(
child: OverRepaintBoundary(
key: overRepaintKey,
child: RepaintBoundary(
child: Column(
children: List.generate(
30,
(i) => Container(
color: Color.fromRGBO(random.nextInt(256), random.nextInt(256), random.nextInt(256), 1.0),
height: 100,
),
),
),
),
),
);
}
}
class OverRepaintBoundary extends StatefulWidget {
final Widget child;
const OverRepaintBoundary({Key key, this.child}) : super(key: key);
@override
OverRepaintBoundaryState createState() => OverRepaintBoundaryState();
}
class OverRepaintBoundaryState extends State<OverRepaintBoundary> {
@override
Widget build(BuildContext context) {
return widget.child;
}
}