C#怎么将 HTML转换为图片或 PDF？

首先是把 HTML 转换为图片。

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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上面这种方法是解析指定URL地址的HTML，然后转换为图片。当然，也可以直接写一些HTML标签。如下：

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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然后把图片转换为PDF，这里需要用到 iTextSharp.dll 这个组件。

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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不过这种生成图片之后再转成PDF，会造成像素的丢失，所以看起来要比图片模糊一点。

还有一种办法就是直接生成PDF，这里需要安装 ABCpdf。不过，这个是收费的。。。

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();
        }
        
    }

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C#怎么将 HTML转换为图片或 PDF？

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