How to convert HTML to image or PDF in C#?

The first step is to convert HTML into images.

public partial class Form1 : Form
    {public Form1()
        {
            InitializeComponent();
        }

        WebBrowser webBrowser = null;public void ConvertToImg()
        {
            webBrowser = new WebBrowser();//是否显式滚动条webBrowser.ScrollBarsEnabled = false;//加载HTML页面的地址webBrowser.Navigate("");            //页面加载完成执行事件webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted);
        }private void webBrowser_DocumentCompleted(object sender, EventArgs e)//这个就是当网页载入完毕后要进行的操作        {//获取解析后HTML的大小System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle;int width = rectangle.Width;int height = rectangle.Height;//设置解析后HTML的可视区域webBrowser.Width = width;
            webBrowser.Height = height;

            Bitmap bitmap = new System.Drawing.Bitmap(width, height);
            webBrowser.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, width, height));//设置图片文件保存路径和图片格式，格式可以自定义string filePath = AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
            bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);
        }private void button1_Click(object sender, EventArgs e)
        {
            ConvertToImg();
        }
    }

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The above method is to parse the HTML of the specified URL address and then convert it into an image. Of course, you can also write some HTML tags directly. As follows:

public partial class Form1 : Form
    {public Form1()
        {
            InitializeComponent();
        }

        WebBrowser webBrowser = null;public void ConvertToImg()
        {string html = "<div><table border = \"1\" cellspacing = \"0\" cellpadding = \"3\" style = \"text-align:center;\"><tr><th style = \"width:60px;\">字段1</th><th style = \"width:60px;\">字段2</th><th style = \"width:60px;\">字段3</th></tr><tr style = \"color:green;\"><td>小明</td><td>22</td><td>185</td></tr><tr style = \"color:red;\"><td>小青</td><td>21</td><td>170</td></tr></table></div>";

            webBrowser = new WebBrowser();//是否显式滚动条webBrowser.ScrollBarsEnabled = false;//加载 htmlwebBrowser.DocumentText = html;            //页面加载完成执行事件webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted);
        }private void webBrowser_DocumentCompleted(object sender, EventArgs e)//这个就是当网页载入完毕后要进行的操作        {//获取解析后HTML的大小System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle;int width = rectangle.Width;int height = rectangle.Height;//设置解析后HTML的可视区域webBrowser.Width = width;
            webBrowser.Height = height;

            Bitmap bitmap = new System.Drawing.Bitmap(width, height);
            webBrowser.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, width, height));//设置图片文件保存路径和图片格式，格式可以自定义string filePath = AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
            bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);
        }private void button1_Click(object sender, EventArgs e)
        {
            ConvertToImg();
        }
    }

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Then convert the image to PDF, which is required here Use the iTextSharp.dll component.

public partial class Form1 : Form
    {public Form1()
        {
            InitializeComponent();
        }

        WebBrowser webBrowser = null;public void ConvertToImg()
        {string html = "<div><table border = \"1\" cellspacing = \"0\" cellpadding = \"3\" style = \"text-align:center;\"><tr><th style = \"width:60px;\">字段1</th><th style = \"width:60px;\">字段2</th><th style = \"width:60px;\">字段3</th></tr><tr style = \"color:green;\"><td>小明</td><td>22</td><td>185</td></tr><tr style = \"color:red;\"><td>小青</td><td>21</td><td>170</td></tr></table></div>";

            webBrowser = new WebBrowser();//是否显式滚动条webBrowser.ScrollBarsEnabled = false;//加载 htmlwebBrowser.DocumentText = html;            //页面加载完成执行事件webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted);
        }private void webBrowser_DocumentCompleted(object sender, EventArgs e)//这个就是当网页载入完毕后要进行的操作        {//获取解析后HTML的大小System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle;int width = rectangle.Width;int height = rectangle.Height;//设置解析后HTML的可视区域webBrowser.Width = width;
            webBrowser.Height = height;

            Bitmap bitmap = new System.Drawing.Bitmap(width, height);
            webBrowser.DrawToBitmap(bitmap, new System.Drawing.Rectangle(0, 0, width, height));//设置图片文件保存路径和图片格式，格式可以自定义string filePath = AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
            bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png);//创建PDFFileStream fileStream = new FileStream(AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".pdf", FileMode.Create);byte[] result = CreatePDF(bitmap, width, height);

            fileStream.Write(result, 0, result.Length);

            fileStream.Close();
            fileStream.Dispose();
        }private void button1_Click(object sender, EventArgs e)
        {
            ConvertToImg();
        }public byte[] CreatePDF(Bitmap bitmap, int width, int height)
        {using (MemoryStream ms = new MemoryStream())
            {
                Document doc = new Document(new iTextSharp.text.Rectangle(0, 0, width, height), 3, 3, 3, 3);    // 左右上下PdfWriter writer = PdfWriter.GetInstance(doc, ms);

                writer.CloseStream = false;

                doc.Open();

                iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(bitmap, System.Drawing.Imaging.ImageFormat.Png);

                img.ScalePercent(100);      // 放缩比例doc.Add(img);       // 添加图片对像                doc.Close();return ms.ToArray();
            }
        }
    }

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However, this kind of generated image and then converting it to PDF will cause the loss of pixels. So it looks a little blurry than the picture.

Another way is to generate PDF directly, where ABCpdf needs to be installed. However, this is chargeable. . .

public partial class Form1 : Form
    {public Form1()
        {
            InitializeComponent();
        }public void ConvertToPDF()
        {string html = "<div><table border = \"1\" cellspacing = \"0\" cellpadding = \"3\" style = \"text-align:center;\"><tr><th style = \"width:60px;\">字段1</th><th style = \"width:60px;\">字段2</th><th style = \"width:60px;\">字段3</th></tr><tr style = \"color:green;\"><td>小明</td><td>22</td><td>185</td></tr><tr style = \"color:red;\"><td>小青</td><td>21</td><td>170</td></tr></table></div>";//创建一个Doc对象Doc doc = new Doc();//Rect默认是文档整个页面大小,这里的Inset表示将Rect左右留出15的空白,上下留出20的空白doc.Rect.Inset(15, 20);//直接设置htmlint docID = doc.AddHtml(html);//设置URL//int docID = doc.AddImageUrl("");//设置字体doc.AddFont("Arial");while (true)
            {//判断是否还有内容if (!doc.Chainable(docID))
                {break;
                }//如果还有内容就添加一页doc.Page = doc.AddPage();//根据ID添加内容并返回页面上该内容对应的新IDdocID = doc.AddImageToChain(docID);
            }string filePath = AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".pdf";

            doc.Save(filePath);

            doc.Clear();
            doc.Dispose();
        }private void button1_Click(object sender, EventArgs e)
        {
            ConvertToPDF();
        }
        
    }

View Code

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