獲取Google PR值一值都是從別人的網站上查到，在網上找了一個Google PageRank .net庫 還有Checksum 算法源代碼，帖上來共享一下（提供C#和VB.NET兩個版本獲取Google PR值源示，另附上Checksum 算法源代碼），演示代碼裡已含有Google PageRank .Net庫，以下是運行效果圖：
Checksum 算法源代碼：
使用實例：
//得到Pagerank值
Console.WriteLine(PRCrack.PageRank.CheckPR("http://www.google.com"));
//得到pagerank checksum
Console.WriteLine(PRCrack.PageRank.OutputCheckSum("http://www.google.com",1));
包含函數：
//輸出指定網址的pagerank checksum
//參數m_Version指定１，表示得到新版本checksum，Google Toolbar版本>>=2.0.114
//參數m_Version指定０，表示得到老版本checksum，Google Toolbar版本<2.0.114
public static string OutputCheckSum(string m_Url,int m_Version)
//輸出制定網址的pagerank
public static string CheckPR(string m_Url)
Checksum 算法源代碼請看詳細內容
using System;
namespace PRCrack
{
/// <summary>
/// Google PageRank的Checksum算法。
/// </summary>
class CheckSum
{
public CheckSum()
{
//
// TODO: 在此處添加構造函數邏輯
//
}
uint GOOGLE_MAGIC=0xE6359A60;
private uint zeroFill(uint a, int b)
{
checked
{
uint z = 0x80000000;
if (Convert.ToBoolean(z & a))
{
a = (a>>1);
a &= (~z);
a |= 0x40000000;
a = (a>>(b-1));
}
else
{
a = (a>>b);
}
}
return a;
}
private uint[] mix(uint a,uint b,uint c)
{
a -= b; a -= c; a ^= (uint)(zeroFill(c,13));
b -= c; b -= a; b ^= (uint)(a<<8);
c -= a; c -= b; c ^= (uint)(zeroFill(b,13));
a -= b; a -= c; a ^= (uint)(zeroFill(c,12));
b -= c; b -= a; b ^= (uint)(a<<16);
c -= a; c -= b; c ^= (uint)(zeroFill(b,5));
a -= b; a -= c; a ^= (uint)(zeroFill(c,3));
b -= c; b -= a; b ^= (uint)(a<<10);
c -= a; c -= b; c ^= (uint)(zeroFill(b,15));
return new uint[3]{a,b,c};
}
private uint GoogleCH(uint[] url, uint length, uint init)
{
if(length==0)
{
length = (uint)url.Length;
}
uint a ,b;
a=b= 0x9E3779B9;
uint c = init;
int k = 0;
uint len = length;
uint[] m_mix=new uint[3];
while(len >= 12)
{
a += (uint)(url[k+0] +(url[k+1]<<8) +(url[k+2]<<16) +(url[k+3]<<24));
b += (uint)(url[k+4] +(url[k+5]<<8) +(url[k+6]<<16) +(url[k+7]<<24));
c += (uint)(url[k+8] +(url[k+9]<<8) +(url[k+10]<<16)+(url[k+11]<<24));
m_mix = mix(a,b,c);
a = m_mix[0]; b = m_mix[1]; c = m_mix[2];
k += 12;
len -= 12;
}
c += length;
switch(len) /* all the case statements fall through */
{
case 11:
{
c+=(uint)(url[k+10]<<24);
c+=(uint)(url[k+9]<<16);
c+=(uint)(url[k+8]<<8);
b+=(uint)(url[k+7]<<24);
b+=(uint)(url[k+6]<<16);
b+=(uint)(url[k+5]<<8);
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 10:
{
c+=(uint)(url[k+9]<<16);
c+=(uint)(url[k+8]<<8);
b+=(uint)(url[k+7]<<24);
b+=(uint)(url[k+6]<<16);
b+=(uint)(url[k+5]<<8);
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 9 :
{
c+=(uint)(url[k+8]<<8);
b+=(uint)(url[k+7]<<24);
b+=(uint)(url[k+6]<<16);
b+=(uint)(url[k+5]<<8);
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
/* the first byte of c is reserved for the length */
case 8 :
{
b+=(uint)(url[k+7]<<24);
b+=(uint)(url[k+6]<<16);
b+=(uint)(url[k+5]<<8);
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 7 :
{
b+=(uint)(url[k+6]<<16);
b+=(uint)(url[k+5]<<8);
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 6 :
{
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 5 :
{
b+=(uint)(url[k+4]);
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 4 :
{
a+=(uint)(url[k+3]<<24);
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 3 :
{
a+=(uint)(url[k+2]<<16);
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 2 :
{
a+=(uint)(url[k+1]<<8);
a+=(uint)(url[k+0]);
break;
}
case 1 :
{
a+=(uint)(url[k+0]);
break;
}
/* case 0: nothing left to add */
}
m_mix = mix(a,b,c);
/*-------------------------------------------- report the result */
return m_mix[2];
}
private uint GoogleCH(string url, uint length)
{
uint[] m_urluint=new uint[url.Length];
for(int i=0;i<url.Length;i++)
{
m_urluint[i]=url[i];
}
return GoogleCH(m_urluint,length,GOOGLE_MAGIC);
}
private uint GoogleCH(string sURL)
{
return GoogleCH(sURL,0);
}
private uint GoogleCH(uint[] url, uint length)
{
return GoogleCH(url, length, GOOGLE_MAGIC);
}
private uint[] c32to8bit(uint[] arr32)
{
uint[] arr8=new uint[arr32.GetLength(0)*4+3];
for(int i=0;i<arr32.GetLength(0);i++)
{
for (int bitOrder=i*4;bitOrder<=i*4+3;bitOrder++)
{
arr8[bitOrder]=arr32[i]&255;
arr32[i]=zeroFill(arr32[i], 8);
}
}
return arr8;
}
//新算法,ToolBar 版本>>=2.0.114
public string CalculateChecksum(string sURL)
{
uint ch=GoogleCH("info:" + sURL);
ch = (((ch/7) << 2) | (((uint)(ch%13))&7));
uint[] prbuf = new uint[20];
prbuf[0] = ch;
for(int I = 1; I < 20; i++) {
prbuf[i] = prbuf[i-1]-9;
}
ch = GoogleCH(c32to8bit(prbuf), 80);
return string.Format("6{0}",ch);
}
//老算法,ToolBar 版本<2.0.114
public string CalculateChecksumOld(string sURL)
{
uint ch=GoogleCH("info:" + sURL);
string CalculateChecksum = "6" + Convert.ToString((ch));
return CalculateChecksum;
}
}
}
