微博內容中的短地址ShortURL
阿新 • • 發佈：2019-02-09
public static string[] ShortUrl(string url)
{
//可以自定義生成MD5加密字元傳前的混合KEY
string key = "Leejor";
//要使用生成URL的字元
string[] chars = new string[]{
"a","b","c","d","e","f","g","h",
"i","j","k","l","m","n","o","p",
"q","r","s","t","u","v","w","x",
"y","z","0","1","2","3","4","5",
"6","7","8","9","A","B","C","D",
"E","F","G","H","I","J","K","L",
"M","N","O","P","Q","R","S","T",
"U","V","W","X","Y","Z"
};
//對傳入網址進行MD5加密
string hex = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(key + url, "md5");
string[] resUrl = new string[4];
for (int i = 0; i < 4; i++)
{
//把加密字元按照8位一組16進位制與0x3FFFFFFF進行位與運算
int hexint = 0x3FFFFFFF & Convert.ToInt32("0x" + hex.Substring(i * 8, 8), 16);
string outChars = string.Empty;
for (int j = 0; j < 6; j++)
{
//把得到的值與0x0000003D進行位與運算，取得字元陣列chars索引
int index = 0x0000003D & hexint;
//把取得的字元相加
outChars += chars[index];
//每次迴圈按位右移5位
hexint = hexint >> 5;
}
//把字串存入對應索引的輸出陣列
resUrl[i] = outChars;
}
return resUrl;
}
test：
ShortUrl(http://www.me3.cn)[0]; //得到值fAVfui ShortUrl(http://www.me3.cn)[1]; //得到值3ayQry ShortUrl(http://www.me3.cn)[2]; //得到值UZzyUr ShortUrl(http://www.me3.cn)[3]; //得到值36rQZn