我正在创建一个内容较大的 PDF 文档。但是，我无法显示 PDF 并且收到错误消息
“此小部件创建了超过 20 个页面。这可能是小部件或文档中的问题。”
我知道文字太大，但我不知道如何让它发挥作用
pdf.addPage(
pw.MultiPage(
pageFormat: PdfPageFormat.a4,
orientation: pw.PageOrientation.portrait,
crossAxisAlignment: pw.CrossAxisAlignment.start,
build: (pw.Context context) {
return <pw.Widget>[
pw.Wrap(
children: <pw.Widget>[
pw.Container(
width: PdfPageFormat.a4.width,
child: pw.Row(
mainAxisSize: pw.MainAxisSize.min,
crossAxisAlignment: pw.CrossAxisAlignment.start,
children: <pw.Widget>[
pw.Expanded(
child: pw.Column(
mainAxisSize: pw.MainAxisSize.min,
crossAxisAlignment: pw.CrossAxisAlignment.start,
children: <pw.Widget>[
pw.SizedBox(height: 8.0),
for (int i = 0; i < data['employers'].length; i++)
pw.Column(
mainAxisSize: pw.MainAxisSize.min,
crossAxisAlignment: pw.CrossAxisAlignment.start,
children: <pw.Widget>[
pw.Text(
"${data['employers'][i]['duties']}",
style: pw.TextStyle(
fontSize: 12.0,
),
softWrap: true,
),
],
),
],
),
),
],
),
),
],
),
];
},
),
);
我需要一些有关如何重组代码的帮助，以便我可以显示 PDF 并将其换行到下一页 文本只是一组 Lorem Ipsum 。
感谢您的帮助
您可以简单地使用这个。
import 'package:ferns_restaurant/constants/Constants.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:pdf/widgets.dart';
import 'package:printing/printing.dart';
import 'package:woocommerce/models/order.dart';
class CustomPrinter {
final pdf = pw.Document();
print(WooOrder order) {
List<LineItems> _product = order.lineItems;
Printing.layoutPdf(
onLayout: (format) {
final doc = pw.Document();
doc.addPage(
pw.MultiPage(
crossAxisAlignment: pw.CrossAxisAlignment.start,
build: (pw.Context context) => <pw.Widget>[
_topHeaderLayout(),
for (int i = 0; i < _product.length; i++)
_productLayout(_product[i]),
]),
);
return doc.save();
},
name: 'order_id_#' + order.id.toString(),
);
}
_topHeaderLayout() {
return new pw.Container(
// height: 60.0,
margin: pw.EdgeInsets.only(bottom: 20.0),
child: pw.Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
pw.Expanded(
child: pw.Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <pw.Widget>[
pw.Container(
child: pw.Text(
'ITEM',
style: pw.TextStyle(
fontWeight: pw.FontWeight.bold,
fontSize: Constants.PRINTER_BASE_FONT_SIZE),
),
),
],
),
),
pw.Expanded(
child: pw.Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <pw.Widget>[
pw.Text(
'PRICE',
style: pw.TextStyle(
fontWeight: pw.FontWeight.bold,
fontSize: Constants.PRINTER_BASE_FONT_SIZE),
),
],
),
)
],
));
}
_productLayout(LineItems item) {
return new pw.Container(
// height: 60.0,
margin: pw.EdgeInsets.only(bottom: 20.0),
child: pw.Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
pw.Expanded(
child: pw.Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <pw.Widget>[
pw.Container(
child: pw.Text(
item.name.toString() + ' - ID: ' + item.id.toString(),
style: pw.TextStyle(
fontWeight: pw.FontWeight.bold,
fontSize: Constants.PRINTER_BASE_FONT_SIZE),
),
),
pw.Container(
child: Text(
'Qty: ' +
item.quantity.toString() +
' x Cost: ' +
'£' +
item.price,
style: pw.TextStyle(
fontWeight: pw.FontWeight.normal,
fontSize: Constants.PRINTER_BASE_FONT_SIZE)),
),
],
),
),
pw.Expanded(
child: pw.Column(
crossAxisAlignment: CrossAxisAlignment.end,
children: <pw.Widget>[
pw.Text(
'£' + item.total.toString(),
style: pw.TextStyle(
fontWeight: pw.FontWeight.normal,
fontSize: Constants.PRINTER_BASE_FONT_SIZE),
),
],
),
)
],
));
}
}
这可能可以解决您的问题
我粘贴了链接的代码，以防您无法输入。
假设我们有一个列表
issuespdf.addPage(
MultiPage(
build: (Context context) => <Widget>[
Wrap(
children: List<Widget>.generate(issues.length, (int index) {
final issue = issues[index];
return Container(
child: Column(
children: <Widget>[
Header(
text: "Issue n°${issue.id}",
textStyle: TextStyle(fontSize: 20)),
Text("Description :",
textAlign: TextAlign.left,
style: TextStyle(fontSize: 15)),
],
),
);
}),
),
],
),
);
我认为这是因为桌子的长度。尝试拆分表格，以免单个表格超过 20 页。
这是类的构造函数
package:pdf/src/widgets/multi_page.dart
(new) MultiPage MultiPage({
PageTheme? pageTheme,
PdfPageFormat? pageFormat,
required List<Widget> Function(Context) build,
MainAxisAlignment mainAxisAlignment = MainAxisAlignment.start,
CrossAxisAlignment crossAxisAlignment = CrossAxisAlignment.start,
Widget Function(Context)? header,
Widget Function(Context)? footer,
ThemeData? theme,
int maxPages = 20, //******* here the default maxPages = 20
PageOrientation? orientation,
EdgeInsets? margin,
TextDirection? textDirection,
})
Containing class: MultiPage
所以我认为你可以计算你的页数并将结果分配给这个属性，或者简单地将数字 20 更改为你想要的。
您必须在 Multipage 包内进行更改。
maxPages默认值为20，您可以增加它。
类 MultiPage 扩展了 Page {
MultiPage({
PageTheme? pageTheme,
PdfPageFormat? pageFormat,
required BuildListCallback build,
this.mainAxisAlignment = MainAxisAlignment.start,
this.crossAxisAlignment = CrossAxisAlignment.start,
this.header,
this.footer,
ThemeData? theme,
**this.maxPages = 1000,**
PageOrientation? orientation,
EdgeInsetsGeometry? margin,
TextDirection? textDirection,
})
doc.addPage(
pw.MultiPage(
maxPages: 100,
.
.
)
)