ASP.NET实现根据URL生成网页缩略图的方法
程序员文章站
2023-12-21 20:56:10
本文实例讲述了asp.net实现根据url生成网页缩略图的方法。分享给大家供大家参考，具体如下：
工作中需要用到根据url生成网页缩略图功能，提前做好准备。
在网上找了...
本文实例讲述了asp.net实现根据url生成网页缩略图的方法。分享给大家供大家参考，具体如下：
工作中需要用到根据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
希望本文所述对大家asp.net程序设计有所帮助。