C# 將 HTML 轉換為圖片或 PDF
阿新 • • 發佈：2017-06-01
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首先是把 HTML 轉換為圖片。
public partial class Form1 : Form { public Form1() { InitializeComponent(); } WebBrowser webBrowser = null; public void ConvertToImg() { webBrowser = new WebBrowser(); //是否顯式滾動條 webBrowser.ScrollBarsEnabled = falseView Code; //加載HTML頁面的地址 webBrowser.Navigate("http://www.baidu.com"); //頁面加載完成執行事件 webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted); } private void webBrowser_DocumentCompleted(objectsender, EventArgs e)//這個就是當網頁載入完畢後要進行的操作 { //獲取解析後HTML的大小 System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle; int width = rectangle.Width; int height = rectangle.Height; //設置解析後HTML的可視區域 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)); //設置圖片文件保存路徑和圖片格式，格式可以自定義 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(); } }
上面這種方法是解析指定URL地址的HTML，然後轉換為圖片。當然，也可以直接寫一些HTML標簽。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(); //是否顯式滾動條 webBrowser.ScrollBarsEnabled = false; //加載 html webBrowser.DocumentText = html; //頁面加載完成執行事件 webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted); } private void webBrowser_DocumentCompleted(object sender, EventArgs e)//這個就是當網頁載入完畢後要進行的操作 { //獲取解析後HTML的大小 System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle; int width = rectangle.Width; int height = rectangle.Height; //設置解析後HTML的可視區域 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)); //設置圖片文件保存路徑和圖片格式，格式可以自定義 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(); } }View Code
然後把圖片轉換為PDF，這裏需要用到 iTextSharp.dll 這個組件。
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(); //是否顯式滾動條 webBrowser.ScrollBarsEnabled = false; //加載 html webBrowser.DocumentText = html; //頁面加載完成執行事件 webBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser_DocumentCompleted); } private void webBrowser_DocumentCompleted(object sender, EventArgs e)//這個就是當網頁載入完畢後要進行的操作 { //獲取解析後HTML的大小 System.Drawing.Rectangle rectangle = webBrowser.Document.Body.ScrollRectangle; int width = rectangle.Width; int height = rectangle.Height; //設置解析後HTML的可視區域 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)); //設置圖片文件保存路徑和圖片格式，格式可以自定義 string filePath = AppDomain.CurrentDomain.BaseDirectory + "../../SaveFIle/" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png"; bitmap.Save(filePath, System.Drawing.Imaging.ImageFormat.Png); //創建PDF FileStream 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); // 放縮比例 doc.Add(img); // 添加圖片對像 doc.Close(); return ms.ToArray(); } } }View Code
不過這種生成圖片之後再轉成PDF，會造成像素的丟失，所以看起來要比圖片模糊一點。
還有一種辦法就是直接生成PDF，這裏需要安裝 ABCpdf。不過，這個是收費的。。。
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>"; //創建一個Doc對象 Doc doc = new Doc(); //Rect默認是文檔整個頁面大小,這裏的Inset表示將Rect左右留出15的空白,上下留出20的空白 doc.Rect.Inset(15, 20); //直接設置html int docID = doc.AddHtml(html); //設置URL //int docID = doc.AddImageUrl("http://www.baidu.com"); //設置字體 doc.AddFont("Arial"); while (true) { //判斷是否還有內容 if (!doc.Chainable(docID)) { break; } //如果還有內容就添加一頁 doc.Page = doc.AddPage(); //根據ID添加內容並返回頁面上該內容對應的新ID docID = 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
C# 將 HTML 轉換為圖片或 PDF