ASP.NET根据URL生成网页缩略图示例程序(C#语言)

浏览数：24 / 时间：2015年06月09日



工作中可能马上要用到根据URL生成网页缩略图功能，提前做好准备。
 
在网上找了份源码，但是有错误:当前线程不在单线程单元中，因此无法实例化 ActiveX 控件“8856f961-340a-11d0-a9”，解决后运行良好，记录在此备用！
 
起始页：Default.aspx
 
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="CaptureToImage._Default" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
  <title>Snap</title>
</head>
<body>
  <form id="form1" runat="server">
  <div>
  <input type="button" onclick="window.open(‘Snap.aspx?url=www.njude.com.cn‘)" value="生成网页缩略图"/>
  </div>
  </form>
</body>
</html>
 
调用页：Snap.aspx
 
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Snap.aspx.cs" Inherits="CaptureToImage.Snap" AspCompat="true" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>
 
PS：红色字体部分是为解决错误增加的代码，强制程序在单线程环境下运行！
 
调用页：Snap.aspx.cs
 
using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Imaging;
 
namespace CaptureToImage
{
    public partial class Snap : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string url = string.Empty;
            url = Request.QueryString[0];
            try
            {
                GetImage thumb = new GetImage(url, 1024, 768, 800, 600);
                System.Drawing.Bitmap x = thumb.GetBitmap();
                x.Save(Response.OutputStream, ImageFormat.Jpeg);
                Response.ContentType = "image/jpeg";
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
        }
    }
}
 
类文件：GetImage.cs
 
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
using System.Web.UI;
 
namespace CaptureToImage
{
    public class GetImage
    {
        int S_Height;
        int S_Width;
        int F_Height;
        int F_Width;
        string MyURL;
 
        public int ScreenHeight
        {
            get
            {
                return S_Height;
            }
            set
            {
                S_Height = value;
            }
        }
 
        public int ScreenWidth
        {
            get
            {
                return S_Width;
            }
            set
            {
                S_Width = value;
            }
        }
 
        public int ImageHeight
        {
            get
            {
                return F_Height;
            }
            set
            {
                F_Height = value;
            }
        }
 
        public int ImageWidth
        {
            get
            {
                return F_Width;
            }
            set
            {
                F_Width = value;
            }
        }
 
        public string WebSite
        {
            get
            {
                return MyURL;
            }
            set
            {
                MyURL = value;
            }
        }
 
        public GetImage(string WebSite, int ScreenWidth, int ScreenHeight, int ImageWidth, int ImageHeight)
        {
            this.WebSite = WebSite;
            this.ScreenHeight = ScreenHeight;
            this.ScreenWidth = ScreenWidth;
            this.ImageHeight = ImageHeight;
            this.ImageWidth = ImageWidth;
        }
        [STAThread]
        public Bitmap GetBitmap()
        {
            WebPageBitmap Shot = new WebPageBitmap(this.WebSite, this.ScreenWidth, this.ScreenHeight);
 
            Shot.GetIt();
            Bitmap Pic = Shot.DrawBitmap(this.ImageHeight, this.ImageWidth);
            return Pic;
        }
    }
 
    public class WebPageBitmap
    {
        WebBrowser MyBrowser;
        string URL;
        int Height;
        int Width;
 
        public WebPageBitmap(string url, int width, int height)
        {
            this.URL = url;
            this.Width = width;
            this.Height = height;
            MyBrowser = new WebBrowser();
            MyBrowser.ScrollBarsEnabled = false;
            MyBrowser.Size = new Size(this.Width, this.Height);
        }
 
        public void GetIt()
        {
            NavigateUrl(this.URL);
            while (MyBrowser.ReadyState != WebBrowserReadyState.Complete)
            {
                Application.DoEvents();
            }
        }
 
        public delegate void DelUserHandler(string url);
 
        public void NavigateUrl(string url)
        {
            try
            {
                if (this.MyBrowser.InvokeRequired)
                {
                    DelUserHandler handler = new DelUserHandler(NavigateUrl);
                    MyBrowser.Invoke(handler, url);
                }
                else
                {
                    this.MyBrowser.Navigate(url);
                }
            }
            catch (Exception ex)
            {
                throw new Exception("NavigateUrl()" + ex.Message);
            }
        }
        public Bitmap DrawBitmap(int theight, int twidth)
        {
            Bitmap myBitmap = new Bitmap(this.Width, this.Height);
            Rectangle DrawRect = new Rectangle(0, 0, this.Width, this.Height);
            MyBrowser.DrawToBitmap(myBitmap, DrawRect);
            System.Drawing.Image imgOutput = myBitmap;
            System.Drawing.Bitmap oThumbNail = new Bitmap(twidth, theight, imgOutput.PixelFormat);
            Graphics g = Graphics.FromImage(oThumbNail);
 
            g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed;
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;
 
            Rectangle oRectangle = new Rectangle(0, 0, twidth, theight);
            g.DrawImage(imgOutput, oRectangle);
 
            try
            {
                return oThumbNail;
            }
            catch
            {
                return null;
            }
            finally
            {
                imgOutput.Dispose();
                imgOutput = null;
                MyBrowser.Dispose();
                MyBrowser = null;
            }
 
        }
    }
}
 
PS：项目中需要添加引用System.Windows.Forms