方法一：
public static string Reverse(string name)
{
if (String.IsNullOrEmpty(name))
{
throw new Exception(“字符串不能为空！”);
}
StringBuilder sb = new StringBuilder(name.Length);
for (int i = name.Length-1; i >= 0; i–)
{
sb.Append(name[i]);
}
return sb.ToString();
}
方法二：.NET3.5以上
public static string Reverse(string name)
{
char[] reverse = name.Reverse().ToArray();
return new string(reverse);
}
方法三：二分法
public static string Reverse(string name)
{
if (String.IsNullOrEmpty(name))
{
throw new Exception(“字符串不能为空！”);
}
char[] nm = name.ToCharArray();
for (int i = 0; i < (nm.Length-1 )/ 2; i++)
{
char q = nm[i];
nm[i]= nm[nm.Length – 1 – i];
nm[nm.Length – 1 – i] = q;
}
return new string(nm);
}