Question

我试图通过Rotativa使用wkhtmltopdf转换一个基本的html页面，该页面使用jquery和highcharts来呈现演示图表。在浏览器中显示时，图表会正确呈现。谁能告诉我我做错了什么？此代码生成一个空白的PDF。

我的观点：

<!DOCTYPE html>

<html>
  <head>
    <title>Highcharts Test</title>

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <style type="text/css">
        #chart { float:left; width:300px; height:300px; }
    </style>

    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script src="http://code.highcharts.com/highcharts.js"></script>
    <script>
        $(function() {
            $('#chart').highcharts({
                chart: {
                    backgroundColor: "red"  
                },
                title: {
                    text: 'Monthly Average Temperature',
                    x: -20 //center
                },
                subtitle: {
                    text: 'Source: WorldClimate.com',
                    x: -20
                },
                xAxis: {
                    categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                        'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
                },
                yAxis: {
                    title: {
                        text: 'Temperature (°C)'
                    },
                    plotLines: [{
                        value: 0,
                        width: 1,
                        color: '#808080'
                    }]
                },
                tooltip: {
                    valueSuffix: '°C'
                },
                legend: {
                    layout: 'vertical',
                    align: 'right',
                    verticalAlign: 'middle',
                    borderWidth: 0
                },
                series: [{
                    name: 'Tokyo',
                    data: [7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6]
                }, {
                    name: 'New York',
                    data: [-0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 24.1, 20.1, 14.1, 8.6, 2.5]
                }, {
                    name: 'Berlin',
                    data: [-0.9, 0.6, 3.5, 8.4, 13.5, 17.0, 18.6, 17.9, 14.3, 9.0, 3.9, 1.0]
                }, {
                    name: 'London',
                    data: [3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 16.6, 14.2, 10.3, 6.6, 4.8]
                }]
            });
        });
    </script>
</head>

<body>
    <div id="chart"></div>
</body>
</html>

这是我的控制器：

using System.Web.Mvc;
using Rotativa;

namespace Completions.MvcApplication.Controllers.Pages
{
public class ReportsController : BasePageController
{
    public ActionResult Systems()
    {
        return new ViewAsPdf();
    } 
}
}

谢谢！
克里斯

Answer 1

我遇到了这个问题，原因是JavaScript错误。您可以通过使用--debug-javascript标志运行wkhtmltopdf来确认这一点。要进行更详细的调试（例如行号），您必须下载QtWeb browser。

特别是在我的情况下，两个问题是Object.values(obj)是未定义的函数，$('a:not(.ignore)')是语法错误（当jQuery 3.1.1尝试使用选择器时）。解决方法是使用Object.keys(obj).map(function (key) { return obj[key] })和$('a').not('.ignore')。

Answer 2

在我看来，图形将在中途停止渲染。所以对我有用的是关闭动画：

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
  let cell = tableView.dequeueReusableCell(withIdentifier: "customMessageCell", for: indexPath)

  cell.ourMessageBackground.backgroundColor = UIColor(displayP3Red: 59/255.0, green: 89/255.0, blue: 152/255.0, alpha: 1)
  cell.ourMessageBody.textColor = UIColor.white
  cell.avatarImageView.backgroundColor = UIColor(white: 0.95, alpha: 1)
  cell.messageBackground.backgroundColor = UIColor(white: 0.95, alpha: 1)

  self.tableView(tableView, willDisplay: cell, forRowAt: indexPath)

  return cell
}

func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
  guard let cell = cell as? CustomMessageCell else { return }

  //Sets cell to message

  let senderId = messageArray[indexPath.row].fromId

  if senderId == Auth.auth().currentUser?.uid as String? {
    //Messages We Sent
    cell.ourMessageBody.text = messageArray[indexPath.row].messageBody

    cell.avatarImageView.isHidden = true
    cell.messageBackground.isHidden = true
    cell.ourMessageBackground.isHidden = false
  } else {
    //Messages someone else sent
    cell.messageBody.text = messageArray[indexPath.row].messageBody

    cell.avatarImageView.isHidden = false
    cell.messageBackground.isHidden = false
    cell.ourMessageBackground.isHidden = true

    //toId ProfileImage
    if let imageID = toId {
      let imagesStorageRef = Storage.storage().reference().child("profilepic/").child(imageID)
      imagesStorageRef.getData(maxSize: 1*1024*1024, completion: { (data, error) in
        if error != nil{
          print(error)
          return
        }

        DispatchQueue.main.async {
          guard let c = tableView.cellForRow(at: indexPath) else { return }

          c.avatarImageView?.image = UIImage(data: data!)
        }

      })

    }
  }
}

这样，一旦生成pdf，便可以准备图表。

使用wkhtmltopdf和highcharts显示空白图表

2 个答案: