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C#实现HTML转图片(网页快照)

发布:2020/9/23 10:44:52作者:管理员 来源:本站 浏览次数:1213

有时候我们需要将网页转成图片,那么可以使用WebBrowser来生成网页快照,废话不多说,代码如下

 1、网页快照帮助类(如果是BS或控制台需要引用System.Windows.Forms类库):


public class WebSnapshotsHelper
    {
        Bitmap m_Bitmap;
        string m_Url;
        int m_BrowserWidth, m_BrowserHeight, m_ThumbnailWidth, m_ThumbnailHeight;
        public WebSnapshotsHelper(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)
        {
            m_Url = Url;
            m_BrowserHeight = BrowserHeight;
            m_BrowserWidth = BrowserWidth;
            m_ThumbnailWidth = ThumbnailWidth;
            m_ThumbnailHeight = ThumbnailHeight;
        }
        public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight)
        {
            WebSnapshotsHelper thumbnailGenerator = new WebSnapshotsHelper(Url, BrowserWidth, BrowserHeight, ThumbnailWidth, ThumbnailHeight);
            return thumbnailGenerator.GenerateWebSiteThumbnailImage();
        }
        public Bitmap GenerateWebSiteThumbnailImage()
        {
            Thread m_thread = new Thread(new ThreadStart(_GenerateWebSiteThumbnailImage));
            m_thread.SetApartmentState(ApartmentState.STA);
            m_thread.Start();
            m_thread.Join();
            return m_Bitmap;
        }
        private void _GenerateWebSiteThumbnailImage()
        {
            WebBrowser m_WebBrowser = new WebBrowser();
            m_WebBrowser.ScrollBarsEnabled = false;
            m_WebBrowser.Navigate(m_Url);
            m_WebBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);
            while (m_WebBrowser.ReadyState != WebBrowserReadyState.Complete)
                Application.DoEvents();
            m_WebBrowser.Dispose();
        }
        private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            WebBrowser m_WebBrowser = (WebBrowser)sender;
            m_WebBrowser.ClientSize = new Size(this.m_BrowserWidth, this.m_BrowserHeight);
            m_WebBrowser.ScrollBarsEnabled = false;
            m_Bitmap = new Bitmap(m_WebBrowser.Bounds.Width, m_WebBrowser.Bounds.Height);
            m_WebBrowser.BringToFront();
            m_WebBrowser.DrawToBitmap(m_Bitmap, m_WebBrowser.Bounds);
            m_Bitmap = (Bitmap)m_Bitmap.GetThumbnailImage(m_ThumbnailWidth, m_ThumbnailHeight, null, IntPtr.Zero);
        }

    }

2、调用:


Bitmap m_Bitmap = WebSnapshotsHelper.GetWebSiteThumbnail("http://www.cnblogs.com/", 800, 1200, 800, 1200); //宽高根据要获取快照的网页决定

m_Bitmap.Save("render_img.bmp", System.Drawing.Imaging.ImageFormat.Bmp); //图片格式可以自由控制

3、效果:

这个可以在 html页面以一张图片为背景,在其中填空,最后调用此Helper方法来生成图片。

最后说一下:这个使用的是WebBrowser为核心,所以生成的html会根据IE内核来渲染,如果页面中使用到了HTML5、CSS3,那推荐部署的服务器装有IE10及以上浏览器,由于是在服务端生成,对客户端浏览器是没有限制。