/// <summary>
/// 将字节数组转换成字符串
/// </summary>
/// <param name = "b">字节数组</param>
/// <returns>返回转换后的字符串</returns>
private string bytetostring(byte[] b)
{
encoding enc = encoding.getencoding("gb2312");
string str = enc.getstring(b);
str = str.substring(0,str.indexof('\0') >= 0 ? str.indexof('\0') : str.length);//去掉无用字符
