这次是对2.0的小修补，2.0交互几乎没有，这次添加了进度条，和文本框，同时由于取得的链接主要会出现错误是：webResponse错误。
针对这种情况，设置了
try
{
webResponse = (HttpWebResponse)webRequest.GetResponse();
}
catch(WebException ex)
{
webResponse = (HttpWebResponse)ex.Response;
}
截取错误信息，这里我们不处理，后续直接判定statecode属性来决定是否还要执行下面的程序。
另外一点变化就是以前是通过将所获取的网页存到文本中去，这次
WebRequest myRequest = WebRequest.Create("http://image.baidu.com/search/index?tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=-1&st=-1&fm=result&fr=&sf=1&fmq=1466307565574_R&pv=&ic=0&nc=1&z=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&word=" + Uri.EscapeDataString(keyWord));
HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
if (myResponse.StatusCode == HttpStatusCode.OK)
{
Stream strm = myResponse.GetResponseStream();
StreamReader sr = new StreamReader(strm);
string line = sr.ReadToEnd();将它全放入了string中。
最后一点是去掉了DownloadPage这个方法，如上，它的功能可以放入按钮的单击事件中实现，没有必要把一件事做两遍。
下面是前台页面：
后台代码：
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms; namespace 百度图片爬虫V2._1
{
public partial class Form1 : Form
{
public delegate void AsynFunction(string s,int i);
public Form1()
{
InitializeComponent();
}
private static string[] getLinks(string html, out int counts)
{
const string pattern = @"http://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?";
Regex r = new Regex(pattern, RegexOptions.IgnoreCase); //新建正则模式
MatchCollection m = r.Matches(html); //获得匹配结果
string[] links = new string[m.Count];
int count = ;
for (int i = ; i < m.Count; i++)
{
if (isValiable(m[i].ToString()))
{
links[count] = m[i].ToString(); //提取出结果
count++;
} }
counts = count;
return links;
}
private void button1_Click(object sender, EventArgs e)
{
string keyWord = this.textBox1.Text;
WebRequest myRequest = WebRequest.Create("http://image.baidu.com/search/index?tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=-1&st=-1&fm=result&fr=&sf=1&fmq=1466307565574_R&pv=&ic=0&nc=1&z=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&word=" + Uri.EscapeDataString(keyWord));
HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
if (myResponse.StatusCode == HttpStatusCode.OK)
{
Stream strm = myResponse.GetResponseStream();
StreamReader sr = new StreamReader(strm);
string line = sr.ReadToEnd();
int counts = ;
string[] str = getLinks(line, out counts);
this.progressBar1.Maximum = counts;
for (int i = ; i < counts; i++)
{
AsynFunction fun = new AsynFunction(savePicture);
fun.BeginInvoke(str[i],i, ar => {
fun.EndInvoke(ar);
this.progressBar1.BeginInvoke(new Action(() =>
{
this.progressBar1.Value =progressBar1.Maximum;
}));
this.textBox2.BeginInvoke(new Action(() =>
{
StringBuilder sb=new StringBuilder();
sb.Append(Environment.NewLine);
// sb.Append(str[i].ToString());
sb.Append("下载结束");
this.textBox2.Text += sb.ToString();
}));
}, fun);
}
}
}
private static bool isValiable(string url)
{
if (url.Contains(".jpg") || url.Contains(".gif") || url.Contains(".png"))
{
return true; //得到一些图片之类的资源
}
return false;
}
public void savePicture(string path,int i)
{
if (path != "" && path != null)
{
DataClasses1DataContext db = new DataClasses1DataContext();
Uri url = new Uri(path);
HttpWebRequest webRequest = (HttpWebRequest)HttpWebRequest.Create(url);
webRequest.Referer = "http://image.baidu.com";
webRequest.Timeout = ;
//设置连接超时时间
webRequest.AllowAutoRedirect = true;
webRequest.Headers.Set("Pragma", "no-cache");
webRequest.UserAgent = "Mozilla-Firefox-Spider(Wenanry)";
HttpWebResponse webResponse;
try
{
webResponse = (HttpWebResponse)webRequest.GetResponse();
}
catch(WebException ex)
{
webResponse = (HttpWebResponse)ex.Response;
} if(webResponse!=null&&webResponse.StatusCode==HttpStatusCode.OK)
{ if (isValiable(path))//判断如果是图片，就将其存储到数据库中。
{
Bitmap myImage = new Bitmap(webResponse.GetResponseStream()); MemoryStream ms = new MemoryStream();
myImage.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
var p = new pictureUrl
{
pictureUrl1 = ms.ToArray()
};
db.pictureUrl.InsertOnSubmit(p);
db.SubmitChanges();
this.progressBar1.BeginInvoke(new Action(() =>
{
this.progressBar1.Value = i;
}));
this.textBox2.BeginInvoke(new Action(() =>
{
StringBuilder sb1 = new StringBuilder();
sb1.Append(path);
sb1.Append("图片下载开始" + Environment.NewLine);
this.textBox2.Text += sb1.ToString();
}));
}
}
}
} private void button2_Click(object sender, EventArgs e)
{
this.Close();
}
}
}