C# 编码转换 UTF8转GB2312 GB2312转UTF8

/// <summary>
/// GB2312转换成UTF8
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static string gb2312_utf8(string text)
        {
//声明字符集   
            System.Text.Encoding utf8, gb2312;
//gb2312   
            gb2312 = System.Text.Encoding.GetEncoding("gb2312");
//utf8   
            utf8 = System.Text.Encoding.GetEncoding("utf-8");
byte[] gb;
            gb = gb2312.GetBytes(text);
            gb = System.Text.Encoding.Convert(gb2312, utf8, gb);
//返回转换后的字符   
return utf8.GetString(gb);
        }

/// <summary>
/// UTF8转换成GB2312
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static string utf8_gb2312(string text)
        {
//声明字符集   
            System.Text.Encoding utf8, gb2312;
//utf8   
            utf8 = System.Text.Encoding.GetEncoding("utf-8");
//gb2312   
            gb2312 = System.Text.Encoding.GetEncoding("gb2312");
byte[] utf;
            utf = utf8.GetBytes(text);
            utf = System.Text.Encoding.Convert(utf8, gb2312, utf);
//返回转换后的字符   
return gb2312.GetString(utf);
        }