ASP.NET實現根據URL生成網頁縮略圖的方法

2024-07-10 13:29:39

字體：大中小

來源：轉載

供稿：網友

這篇文章主要介紹了ASP.NET實現根據URL生成網頁縮略圖的方法,結合實例較為詳細的分析了asp.net生成網頁縮略圖的詳細實現技巧與相關注意事項,需要的朋友可以參考下

本文實例講述了ASP.NET實現根據URL生成網頁縮略圖的方法。分享給大家供大家參考，具體如下：

工作中需要用到根據URL生成網頁縮略圖功能，提前做好準備。

在網上找了份源碼，但是有錯誤:當前線程不在單線程單元中，因此無法實例化 ActiveX 控件“8856f961-340a-11d0-a9”，解決后運行良好，記錄在此備用!

起始頁：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="生成網頁縮略圖"/>

</div>

</form>

</body>

</html>

調用頁：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>無標題頁</title>

</head>

<body>

<form id="form1" runat="server">

<div>

</div>

</form>

</body>

</html>

PS：紅色字體部分是為解決錯誤增加的代碼，強制程序在單線程環境下運行!

調用頁：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);

}

}

}

}

類文件：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;

}

}

}

}