C#：網頁畫面轉成圖檔 (web page to image)

透過 WebBrowser 開啟網頁再擷取成圖檔儲存。

加入參考：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

主要程式，新增 WebSiteThumbnail 類別：

public class WebSiteThumbnail
{
    Bitmap m_Bitmap;
    string m_Url;
    int m_BrowserWidth, m_BrowserHeight, m_ThumbnailWidth, m_ThumbnailHeight;

    public WebSiteThumbnail(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)
    {
        WebSiteThumbnail thumbnailGenerator = new WebSiteThumbnail(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);
    }
}

使用方法1 (輸出到網頁串流)：

Bitmap m_Bitmap = WebSiteThumbnail.GetWebSiteThumbnail("https://www.google.com.tw", 600, 600, 600, 600);
MemoryStream ms = new MemoryStream();
m_Bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);//JPG、GIF、PNG...
byte[] buff = ms.ToArray();
Response.BinaryWrite(buff);

使用方法2 (儲存為檔案)：

Bitmap m_Bitmap = WebSiteThumbnail.GetWebSiteThumbnail("https://www.google.com.tw", 600, 600, 600, 600);
MemoryStream ms = new MemoryStream();
m_Bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);//JPG、GIF、PNG...
System.Drawing.Image postImage = System.Drawing.Image.FromStream(ms);
postImage.Save("D:\\test.Png",System.Drawing.Imaging.ImageFormat.Png); 

原始碼出處：http://m.it610.com/article/1210098.htm
微軟相關資料：https://code.msdn.microsoft.com/windowsapps/CSWinFormSaveWebpageToImage-4dcb7aa6

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