采集网页图片 asp.net采集网页图片的具体方法
人气:0想了解asp.net采集网页图片的具体方法的相关内容吗，在本文为您仔细讲解采集网页图片的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：采集,网页,图片，下面大家一起来学习吧。
在网上找了下大多都是通过字符串操作找出img标签，这种方式操作起来比较麻烦，而且代码看起来比较累。这里我用的方法是通过WebBrowser来加载一个页面，然后HTMLDocument类来操作省去了字符串操作的步骤，直接调用GetElementsByTagName把所有图片地址返回到一个HtmlElementCollection对象里。代码如下：
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Net;
using System.IO;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public class GatherPic
{
private string savePath;
private string getUrl;
private WebBrowser wb;
private int iImgCount;
//初始化参数
public GatherPic(string sWebUrl, string sSavePath)
{
this.getUrl = sWebUrl;
this.savePath = sSavePath;
}
//开始采集
public bool start()
{
if (getUrl.Trim().Equals(""))
{
MessageBox.Show("哪来的虾米连网址都没输！");
return false;
}
this.wb = new WebBrowser();
this.wb.Navigate(getUrl);
//委托事件
this.wb.DocumentCompleted += new System.Windows.Forms.WebBrowserDocumentCompletedEventHandler(DocumentCompleted);
return true;
}
//WebBrowser.DocumentCompleted委托事件
private void DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
//页面里框架iframe加载完成不掉用SearchImgList()
if (e.Url != wb.Document.Url) return;
SearchImgList();
}
//检查出所有图片并采集到本地
public void SearchImgList()
{
string sImgUrl;
//取得所有图片地址
HtmlElementCollection elemColl = this.wb.Document.GetElementsByTagName("img");
this.iImgCount = elemColl.Count;
foreach (HtmlElement elem in elemColl)
{
sImgUrl = elem.GetAttribute("src");
//调用保存远程图片函数
SaveImageFromWeb(sImgUrl, this.savePath);
}
}
//保存远程图片函数
public int SaveImageFromWeb(string imgUrl, string path)
{
string imgName = imgUrl.ToString().Substring(imgUrl.ToString().LastIndexOf("/") + 1);
path = path + "\\" + imgName;
string defaultType = ".jpg";
string[] imgTypes = new string[] { ".jpg", ".jpeg", ".png", ".gif", ".bmp" };
string imgType = imgUrl.ToString().Substring(imgUrl.ToString().LastIndexOf("."));
foreach (string it in imgTypes)
{
if (imgType.ToLower().Equals(it))
break;
if (it.Equals(".bmp"))
imgType = defaultType;
}
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(imgUrl);
request.UserAgent = "Mozilla/6.0 (MSIE 6.0; Windows NT 5.1; Natas.Robot)";
request.Timeout = 10000;
WebResponse response = request.GetResponse();
Stream stream = response.GetResponseStream();
if (response.ContentType.ToLower().StartsWith("image/"))
{
byte[] arrayByte = new byte[1024];
int imgLong = (int)response.ContentLength;
int l = 0;
// CreateDirectory(path);
FileStream fso = new FileStream(path, FileMode.Create);
while (l < imgLong)
{
int i = stream.Read(arrayByte, 0, 1024);
fso.Write(arrayByte, 0, i);
l += i;
}
fso.Close();
stream.Close();
response.Close();
return 1;
}
else
{
return 0;
}
}
catch (WebException)
{
return 0;
}
catch (UriFormatException)
{
return 0;
}
}
}
}
//-----------------调用代码--------------------
GatherPic gatherpic = new GatherPic(“http://www.baidu.com”,"C:\test");
//请确保c:\下存在test路径
gatherpic.start()
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