如何用iText7在C#中配置PDF页面设置与边距并限制单页

云原生阿岚

2026-7-2

使用iText7将HTML转换为带指定设置的单页PDF

需求说明

我正在开发一款应用，需将指定HTML转换为单页PDF。现有使用iText7的C#转换代码，需添加以下设置：

DefaultEncoding = "utf-8"
PaperSize = PaperKind.A4
Orientation = Orientation.Portrait
Margins = new MarginSettings { Top = 10, Bottom = 10 }

原HTML代码

string htmlContent = $@"<!DOCTYPE html>
                                        <html lang=""en"">
                                        <head>
                                            <meta charset=""UTF-8"">
                                            <meta name=""viewport"" content=""width=device-width, initial-scale=1.0"">
                                        </head>
                                        <body>
                                            <div style=""position: relative;"">
                                                <div style=""padding: 20px; padding-bottom: 0px;"">
                                                    <img height=""80px"" width=""220px"" src=""{image1Url}"" alt="""" srcset="""">
                                                    <p style=""margin-top: -40pt;padding-left: 188pt;text-indent: 0pt;text-align: left;"">
                                                        <span style="" color: #007E00; font-family:Arial, sans-serif; font-style: italic; font-weight: normal; font-size: 14pt;"">1</span>
                                                        <span style="" color: #007E00; font-family:Arial, sans-serif; font-style: italic; font-weight: normal; font-size: 9pt; vertical-align: 4pt;"">ère</span>
                                                        <span style="" color: #007E00; font-family:Arial, sans-serif; font-style: italic; font-weight: normal; font-size: 14pt;"">solution
                                                            de paiement par mobile à Madagascar</span>
                                                    </p>
                                                </div>
                                                <div style=""border-bottom: 20px solid #ffde00; margin-top: -5px;""></div>
                                                <div style=""padding: 20px;"">
                                                    <div style=""margin-bottom: 20px;"">
                                                        <h3>ATTESTATION DE TRANSFERT VIA MVOLA
                                                        </h3>
                                                    </div>
                                                    <div style=""margin-bottom: 50px;"">
                                                        <p style=""margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                            {dto.Name}</p>
                                                        <p style=""margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                            Mobile : {dto.Msisdn}</p>
                                                        <p style=""margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                            E-mail : {dto.Email}</p>
                                                    </div>
                                                    <div style=""border-top: 3px solid #ffde00; border-bottom: 3px solid #ffde00; padding: 20px 0px; margin-bottom: 50px;"">
                                                        <table style=""width: 100%;"">
                                                            <thead>
                                                                <tr>
                                                                    <th style=""text-align: start;"">Libellé</th>
                                                                    <th style=""text-align: start;"">Date</th>
                                                                    <th style=""text-align: start;"">Référence</th>
                                                                    <th style=""text-align: start;"">Montant</th>
                                                                </tr>
                                                            </thead>
                                                            <tbody>
                                                                <tr>
                                                                    <td style=""text-align: start;"">{dto.Description}</td>
                                                                    <td style=""text-align: start;"">{dto.TransDate}</td>
                                                                    <td style=""text-align: start;"">{dto.TransID}</td>
                                                                    <td style=""text-align: start;"">{dto.Amount} Ar</td>
                                                                </tr>
                                                            </tbody>
                                                        </table>
                                                    </div>
                                                    <div style=""padding: 20px; margin-bottom: 40px;"">
                                                        <p style=""margin: 0px; margin-bottom: 5px; font-size: 14px; font-family: Arial, Helvetica, sans-serif;"">
                                                            À conserver pour vos archives</p>
                                                        <h3 style=""margin-bottom: 40px;"">TOUJOURS PLUS SIMPLE AVEC MVOLA!</h3>
                                                         <div style=""style=""height: 700px;"">
                                                            <img src=""{image2Url}"" alt="""" height=""auto"" width=""100%"" style=""max-height: 600px;"">
                                                        </div>
                                                    </div>
                                                </div>
                                                <div style=""margin-bottom: 20px; padding: 20px; background-color: #ffde00;"">
                                                    <table style=""width: 100%;"">
                                                        <tbody>

                                                            <tr>
                                                                <td style=""width: 50%; text-align: start;"">
                                                                    <div style=""margin-bottom: 10px; color: #007E00;"">
                                                                        <p
                                                                            style="" margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                                            Service Client MVola : 807</p>
                                                                        <p
                                                                            style=""margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                                            E-mail : <a href=""mailto:mvola@telma.mg"">mvola@telma.mg</a></p>
                                                                        <p
                                                                            style=""margin: 0px; margin-bottom: 5px; font-size: 12px; font-family: Arial, Helvetica, sans-serif;"">
                                                                            <a href=""http://www.mvola.mg/MVola_mobile_money.php""> www.mvola.mg</a>
                                                                        </p>
                                                                    </div>
                                                                </td>
                                                                <td style=""width: 50%; text-align: end;"">
                                                                    <div>
                                                                        <img src=""{image3Url}"" alt="""" srcset="""" height=""80px"" width=""220px"">
                                                                    </div>
                                                                </td>
                                                            </tr>

                                                        </tbody>
                                                    </table>
                                                </div>
                                            </div>
                                        </body>
                                              </html>";

原C#代码

public string GeneratePdfFromHtmlAndConvertToBase64(string htmlContent)
{
    try
    {
        string base64String;
        _logger.LogInformation($"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, Request: {htmlContent}");

        using (var memoryStream = new MemoryStream())
        {
            var writerProperties = new WriterProperties();

            using (var pdfWriter = new PdfWriter(memoryStream, writerProperties))
            {
                using (var pdfDocument = new PdfDocument(pdfWriter))
                {
                    var doc = new Document(pdfDocument);
                    doc.SetMargins(10, 10, 10, 10);
                    
                    pdfDocument.SetDefaultPageSize(PageSize.A4);
                    HtmlConverter.ConvertToPdf(htmlContent, pdfDocument, new ConverterProperties());
                }
            }

            var bytes = memoryStream.ToArray();
            base64String = Convert.ToBase64String(bytes);
        }

        _logger.LogInformation($"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, base64String: {base64String}");

        return base64String;
    }
    catch (Exception ex)
    {
        _logger.LogError(ex, $"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, Exception Occurred: {ex.Message}");
        return null;
    }
}

修改后的C#代码及说明

要满足所有指定设置，需对ConverterProperties进行配置，并调整页面相关设置：

UTF-8编码：通过ConverterProperties.SetCharset("utf-8")指定编码；
A4纵向纸张：PageSize.A4默认即为纵向，直接设置为默认页面大小即可；
上下边距10：通过MarginSettings设置上下边距，左右边距可根据需求调整；
移除原代码中doc.SetMargins(...)，避免与HTML转换的边距设置冲突。

修改后的完整代码：

public string GeneratePdfFromHtmlAndConvertToBase64(string htmlContent)
{
    try
    {
        string base64String;
        _logger.LogInformation($"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, Request: {htmlContent}");

        using (var memoryStream = new MemoryStream())
        {
            var writerProperties = new WriterProperties();

            using (var pdfWriter = new PdfWriter(memoryStream, writerProperties))
            {
                using (var pdfDocument = new PdfDocument(pdfWriter))
                {
                    // 设置A4纵向为默认页面大小
                    pdfDocument.SetDefaultPageSize(PageSize.A4);

                    // 配置转换属性
                    var converterProperties = new ConverterProperties()
                        // 设置UTF-8编码
                        .SetCharset("utf-8")
                        // 设置边距：上下10，左右可按需调整
                        .SetMarginSettings(new MarginSettings { Top = 10, Bottom = 10, Left = 0, Right = 0 });

                    // 执行HTML转PDF
                    HtmlConverter.ConvertToPdf(htmlContent, pdfDocument, converterProperties);
                }
            }

            var bytes = memoryStream.ToArray();
            base64String = Convert.ToBase64String(bytes);
        }

        _logger.LogInformation($"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, base64String: {base64String}");

        return base64String;
    }
    catch (Exception ex)
    {
        _logger.LogError(ex, $"Request ID: {_localSessionManager.InternalTransectionSessionID} - GeneratePdfFromHtmlAndConvertToBase64, Exception Occurred: {ex.Message}");
        return null;
    }
}

内容的提问来源于stack exchange，提问作者Kamran Khan

如何用iText7在C#中配置PDF页面设置与边距并限制单页

需求说明 #

原HTML代码 #

原C#代码 #

修改后的C#代码及说明 #

需求说明

原HTML代码

原C#代码

修改后的C#代码及说明