请问字符编码的代码

请教字符编码的代码
要把下面字符串：
/wEWCAK4kpaYCgL8rs2vCgLAnbyjAQL+leu8DgKKkorhCwKLkorhCwLJ2fTxBAKL0KnPDEtAPgjAGjK9a3m9r/b3gx+KmIdT
转换成：
%2FwEWCAK4kpaYCgL8rs2vCgLAnbyjAQL%2Bleu8DgKKkorhCwKLkorhCwLJ2fTxBAKL0KnPDEtAPgjAGjK9a3m9r%2Fb3gx%2BKmIdT

c#要怎么写

[解决办法]

C# code

        string str = "/wEWCAK4kpaYCgL8rs2vCgLAnbyjAQL+leu8DgKKkorhCwKLkorhCwLJ2fTxBAKL0KnPDEtAPgjAGjK9a3m9r/b3gx+KmIdT";        Response.Write(HttpUtility.UrlEncode(str));//%2fwEWCAK4kpaYCgL8rs2vCgLAnbyjAQL%2bleu8DgKKkorhCwKLkorhCwLJ2fTxBAKL0KnPDEtAPgjAGjK9a3m9r%2fb3gx%2bKmIdT