找出超链接(无重复链接)-------自己有点小用，就简单写了一个，以后方便用，大家分享！

/// <summary>

/// 将2.txt中的超链接放入1.txt

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void button1_Click(object sender, EventArgs e)

{

FileStream fs = new FileStream("C:\\2.txt",

FileMode.Open);

StreamReader m_streamReader = new StreamReader(fs);

m_streamReader.BaseStream.Seek(0, SeekOrigin.Begin);

string strLine = m_streamReader.ReadToEnd();

string exp = "[a-zA-z]+://[^\\s]*";

Regex regex = new Regex(exp, RegexOptions.IgnoreCase);

MatchCollection mc = regex.Matches(strLine);

ArrayList al = new ArrayList();

StringBuilder sb = new StringBuilder();

using (System.IO.StreamWriter file = new System.IO.StreamWriter(@"C:\\1.txt", true))

{

for (int i = 1; i <= mc.Count; i++)

{

if (!al.Contains(mc[i - 1].Value))

{

al.Add(mc[i - 1].Value);

file.WriteLine(i + ":" + mc[i - 1].Value + "/n");

}

}

}

m_streamReader.Close();

m_streamReader.Dispose();

fs.Close();

fs.Dispose();

}