Flutter在打印机中创建汉字PDF文件并打印文件 [英] Flutter create Chinese character PDF file and print file in printer
本文介绍了Flutter在打印机中创建汉字PDF文件并打印文件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试开发一个Flutter应用程序，该应用程序可以将文档打印到纸张上。我只能使用英文字符。
I am trying to develop a Flutter application which can print a document to paper. I am only able to get it to work with English characters. Can someone help to make it work with Chinese please?
这是我的 main.dart
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';
import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:pdf/pdf.dart';
import 'package:printing/printing.dart';
void main() => runApp(new MaterialApp(home: new MyApp()));
class MyApp extends StatelessWidget {
final shareWidget = new GlobalKey();
Future<PDFDocument> _generateDocument() async{
final pdf = new PDFDocument(deflate: zlib.encode);
final page = new PDFPage(pdf, pageFormat: PDFPageFormat(216.0, 384.0));
final g = page.getGraphics();
final top = page.pageFormat.height;
g.setColor(new PDFColor(0.0, 1.0, 1.0));
var font = await rootBundle.load("assets/GenYoMinTW-Heavy.ttf");
PDFTTFFont ttf = new PDFTTFFont(pdf, font);
//PDFTTFFont ttf = new PDFTTFFont(pdf, (new File("assets/open-sans.ttf").readAsBytesSync() as Uint8List).buffer.asByteData());
g.setColor(new PDFColor(0.3, 0.3, 0.3));
//var encoded = utf8.encode("檯號： 1");
g.drawString(ttf, 20.0, '\u4f60\u597d', 10.0 * PDFPageFormat.MM, top - 10.0 * PDFPageFormat.MM);
return pdf;
}
void _printPdf() {
print("Print ...");
// final pdf = _generateDocument();
// Printing.printPdf(document: pdf);
_generateDocument().then((pdf) {
Printing.printPdf(document: pdf);
});
}
void _sharePdf() {
print("Share ...");
//final pdf = _generateDocument();
// Calculate the widget center for iPad sharing popup position
final RenderBox referenceBox =
shareWidget.currentContext.findRenderObject();
final topLeft =
referenceBox.localToGlobal(referenceBox.paintBounds.topLeft);
final bottomRight =
referenceBox.localToGlobal(referenceBox.paintBounds.bottomRight);
final bounds = new Rect.fromPoints(topLeft, bottomRight);
_generateDocument().then((pdf) {
Printing.sharePdf(document: pdf, bounds: bounds);
});
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: const Text('Printing example'),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
new RaisedButton(
child: new Text('Print Document'), onPressed: _printPdf),
new RaisedButton(
key: shareWidget,
child: new Text('Share Document'),
onPressed: _sharePdf),
],
),
),
);
}
}
在以下情况下，屏幕将不会进入打印预览页面使用中文Unicode打印。
The Screen will not go to the print preview page when using Chinese Unicode to print.
如果有帮助，这是我的pubspec.yaml：
If it helps, here is my pubspec.yaml:
name: testmanual
description: A new Flutter application.
# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# Read more about versioning at semver.org.
version: 1.0.0+1
environment:
sdk: ">=2.0.0-dev.68.0 <3.0.0"
dependencies:
flutter:
sdk: flutter
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.2
image_picker: ^0.4.10
flutter_mailer: ^0.1.1
video_player: ^0.6.5
datetime_picker_formfield: ^0.1.3
device_calendar: ^0.0.6
connectivity: ^0.3.1
path_provider: "^0.4.0"
flutter_date_picker: ^0.1.2
image_form_field: ^0.0.2
flutter_youtube: "^1.1.1"
cached_network_image: ^0.4.2
qr_flutter: ^1.1.3
share: ^0.5.3
audioplayers: ^0.7.8
chewie: ^0.7.0
printing: ^1.0.5
pdf: ^1.0.6
font_awesome_flutter: ^8.1.0
dev_dependencies:
flutter_test:
sdk: flutter
# For information on the generic Dart part of this file, see the
# following page: https://www.dartlang.org/tools/pub/pubspec
# The following section is specific to Flutter.
flutter:
# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true
# To add assets to your application, add an assets section, like this:
assets:
- assets/ding.wav
- assets/qpon_download.pdf
- assets/open-sans.ttf
- assets/GenYoMinTW-Heavy.ttf
# An image asset can refer to one or more resolution-specific "variants", see
# https://flutter.io/assets-and-images/#resolution-aware.
# For details regarding adding assets from package dependencies, see
# https://flutter.io/assets-and-images/#from-packages
# To add custom fonts to your application, add a fonts section here,
# in this "flutter" section. Each entry in this list should have a
# "family" key with the font family name, and a "fonts" key with a
# list giving the asset and other descriptors for the font. For
# example:
# fonts:
# - family: Schyler
# fonts:
# - asset: fonts/Schyler-Regular.ttf
# - asset: fonts/Schyler-Italic.ttf
# style: italic
# - family: Trajan Pro
# fonts:
# - asset: fonts/TrajanPro.ttf
# - asset: fonts/TrajanPro_Bold.ttf
# weight: 700
#
# For details regarding fonts from package dependencies,
# see https://flutter.io/custom-fonts/#from-packages
推荐答案
不幸的是，看起来PDF库只能使用ASCII字符。在这里，我已附加了代码以英语生成PFD。它还可以访问移动设备的共享页面，因此您可以将PDF保存到另一个应用程序，或通过AirPrint之类的方法将其发送到打印机。希望这可以帮助。我还重新编写了代码。我会尽快向您的回购请求。您可能想向[PDF] [1]库的作者David PHAM-VAN提交错误报告。
Unfortunately it looks like the PDF library can only use ASCII characters. Here, I have attached code to generate a PFD with the English language. It also accesses the 'share' page of the mobile device so you can save the PDF to another app or send it to the printer via methods like AirPrint. Hope this helps. I have also re-written the code. I will make a pull request to your repo soon. You may want to file a bug report to David PHAM-VAN who is the author of the [PDF][1] library.
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_share/flutter_share.dart';
import 'package:pdf/pdf.dart';
import 'package:path_provider/path_provider.dart';
void main() => runApp(new MaterialApp(home: new MyApp()));
class MyApp extends StatelessWidget {
Future<PDFDocument> _generateDocument() async{
final pdf = new PDFDocument();
final page = new PDFPage(pdf, pageFormat: PDFPageFormat(216.0, 384.0));
final top = page.pageFormat.height;
final g = page.getGraphics();
final font = new PDFFont(pdf);
g.setColor(new PDFColor(0.3, 0.3, 0.3));
String text = "We can only use ASCII characters";
g.drawString(font, 12.0, text, 1.0 * PDFPageFormat.mm, top-10*PDFPageFormat.mm);
await _localFile.then((File file){
print("Saving local file");
file.writeAsBytesSync(pdf.save());
});
return pdf;
}
void _sharePDF() {
print("Print ...");
_generateDocument().then((pdf) {
_localPath.then((String path){
FlutterShare.share(fileUrl: "$path/pdf.pdf");
});
});
}
Future<File> get _localFile async {
final path = await _localPath;
return File('$path/pdf.pdf');
}
Future<String> get _localPath async {
final directory = await getApplicationDocumentsDirectory();
return directory.path;
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: const Text('Printing example'),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
new RaisedButton(
child: new Text('Print Document'), onPressed: _sharePDF)
],
),
),
);
}
}
编辑：不能很快弄清楚如何发送拉取请求，因此只需用以下代码替换main.dart即可。这也是您想要的pubspec.yaml代码/
I can't figure out quickly how to send a pull request so just replace your main.dart with this code. Also this is the pubspec.yaml code you want/
name: testmanual
description: A new Flutter application.
# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# Read more about versioning at semver.org.
version: 1.0.0+1
environment:
sdk: ">=2.0.0-dev.68.0 <3.0.0"
dependencies:
flutter:
sdk: flutter
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.2
image_picker: ^0.4.10
path_provider: "^0.4.0"
qr_flutter: ^1.1.3
printing: ^1.0.5
pdf: ^1.0.6
flutter_share: ^0.0.4
# flutter_mailer: ^0.1.1
# video_player: ^0.6.5
# datetime_picker_formfield: ^0.1.3
# device_calendar: ^0.0.6
# connectivity: ^0.3.1
# flutter_date_picker: ^0.1.2
# image_form_field: ^0.0.2
# flutter_youtube: "^1.1.1"
# cached_network_image: ^0.4.2
# share: ^0.5.3
# audioplayers: ^0.7.8
# chewie: ^0.7.0
# font_awesome_flutter: ^8.1.0
dev_dependencies:
flutter_test:
sdk: flutter
# For information on the generic Dart part of this file, see the
# following page: https://www.dartlang.org/tools/pub/pubspec
# The following section is specific to Flutter.
flutter:
# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true
# To add assets to your application, add an assets section, like this:
assets:
- assets/ding.wav
- assets/qpon_download.pdf
- assets/open-sans.ttf
- assets/GenYoMinTW-Heavy.ttf
# An image asset can refer to one or more resolution-specific "variants", see
# https://flutter.io/assets-and-images/#resolution-aware.
# For details regarding adding assets from package dependencies, see
# https://flutter.io/assets-and-images/#from-packages
# To add custom fonts to your application, add a fonts section here,
# in this "flutter" section. Each entry in this list should have a
# "family" key with the font family name, and a "fonts" key with a
# list giving the asset and other descriptors for the font. For
# example:
# fonts:
# - family: Schyler
# fonts:
# - asset: fonts/Schyler-Regular.ttf
# - asset: fonts/Schyler-Italic.ttf
# style: italic
# - family: Trajan Pro
# fonts:
# - asset: fonts/TrajanPro.ttf
# - asset: fonts/TrajanPro_Bold.ttf
# weight: 700
#
# For details regarding fonts from package dependencies,
# see https://flutter.io/custom-fonts/#from-packages
编辑2：
重要！当您将PDF写入文件时，这会将其直接写入手机。例如，如果您使用的是iOS，请转到文件应用，您将看到一个名为<您的应用名称> 并在其中存在 pdf.pdf。您可能需要做一些清洁工作或找到其他共享方法。
Important! When you write the PDF to a file, this writes it directly to the phone. For example, if you are on iOS, go to the Files app and you will see a folder called <your app name> and inside, there will be 'pdf.pdf'. You may want to do a bit of cleaning or find another sharing method.
[1]: https://pub.dartlang.org/packages/pdf
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