Question

im正在扑朔迷离地在pdf生成器应用程序上工作，但是当我想将图像添加到pdf时，花费的时间也太长了，我也想知道如何添加多个图像。

我使用3个库，图像选择器-pdf-打印

这是我的代码：

Future getImage() async {
  var image = await ImagePicker.pickImage(source: ImageSource.gallery);
  final tempDir = await getTemporaryDirectory();
  final path = tempDir.path;
  int rand = new Math.Random().nextInt(10000000);
  imge.Image imagee = imge.decodeImage(image.readAsBytesSync());
  imge.Image smallerImage = imge.copyResize(imagee, 500);
  setState(() {
   var  _image =  new   File('$path/img_$rand.jpg')..writeAsBytesSync(imge.encodeJpg(smallerImage, quality: 85));

   _sharePdf(_image);
  });


}



 PDFDocument _generateDocument(File _image)  {
    final pdf = new PDFDocument(deflate: zlib.encode);
    final page = new PDFPage(pdf, pageFormat: PDFPageFormat.LETTER);
    final g = page.getGraphics();
    final font = new PDFFont(pdf);
    final top = page.pageFormat.height;

    print(top);

    imge.Image img = imge.decodeImage(_image.readAsBytesSync());


    PDFImage image = new PDFImage(
       pdf,
       image: img.data.buffer.asUint8List(),
       width: img.width,
       height: img.height);

   g.drawImage(image, 100.0, top - 150.0, 80.0, 100.0);

    return pdf;
  }

  void _sharePdf(File _image) {
    print("Share ...");
    final pdf = _generateDocument(_image);

    // 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);

    Printing.sharePdf(document: pdf, bounds: bounds);
  }

然后我调用函数getImage（）。

我选择图像后，需要花费2-3分钟的时间，所有内容都会冻结，然后您可以共享pdf！

Answer 1

用于iOS和Android的Flutter_html_to_pdf插件，用于从HTML生成PDF文件。

使用：

https://pub.dev/packages/flutter_html_to_pdf

代替：

https://pub.dev/packages/pdf

首先，在您的pubspec.yaml文件中添加flutter_html_to_pdf作为依赖项。

 dependencies:
 flutter_html_to_pdf: ^0.5.2

现在在Dart代码中，您可以使用：

 import 'package:flutter_html_to_pdf/flutter_html_to_pdf.dart';

用法＃

 var htmlContent =
 """
 <!DOCTYPE html>
 <html>
 <head>
   <style>
   table, th, td {
   border: 1px solid black;
     border-collapse: collapse;
   }
   th, td, p {
     padding: 5px;
     text-align: left;
   }
   </style>
 </head>
   <body>
     <h2>PDF Generated with flutter_html_to_pdf plugin</h2>
     <table style="width:100%">
       <caption>Sample HTML Table</caption>
       <tr>
         <th>Month</th>
         <th>Savings</th>
       </tr>
       <tr>
        <td>January</td>
         <td>100</td>
       </tr>
       <tr>
         <td>February</td>
         <td>50</td>
       </tr>
     </table>
     <p>Image loaded from web</p>
     <img src="https://i.imgur.com/wxaJsXF.png" alt="web-img">
   </body>
 </html>
 """;

 var targetPath = "/your/sample/path";
 var targetFileName = "example_pdf_file"

 var generatedPdfFile = await FlutterHtmlToPdf.convertFromHtmlContent(
     htmlContent, targetPath, targetFileName);

您还可以传递内部带有HTML内容的File对象作为参数

 var file = File("/sample_path/example.html");
 var generatedPdfFile = await FlutterHtmlToPdf.convertFromHtmlFile(
     file, targetPath, targetFileName);

甚至只是该文件的路径

 var filePath = "/sample_path/example.html";
 var generatedPdfFile = await FlutterHtmlToPdf.convertFromHtmlFilePath(
     filePath, targetPath, targetFileName);

图片如果要将设备中的本地图片添加到HTML，则需要将图片的路径作为src值传递。

 <img src="file:///storage/example/your_sample_image.png" alt="web-img">

或者如果要使用图像File对象

 <img src="${imageFile.path}" alt="web-img">

对于多张图片，您可以添加多个标签，例如：

 <img src="your source" alt="your alternative">
 <img src="your source" alt="your alternative">
 <img src="your source" alt="your alternative">
 <img src="your source" alt="your alternative">
 <img src="your source" alt="your alternative">

颤振pdf生成图像太慢

1 个答案: