ASP.NET根据URL生成网页缩略图示例程序(C#语言)

刺骨的言语ヽ痛彻心扉 2021-12-23 11:53 143阅读 0赞

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][http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]">

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][http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]">

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

转载于:https://www.cnblogs.com/guoxiaowen/archive/2012/02/16/2353900.html

[http_www.w3.org_TR_xhtml1_DTD_xhtml1-transitional.dtd]: http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd
[http_www.w3.org_1999_xhtml]: http://www.w3.org/1999/xhtml