Question

用C#将一串字符串中大写字母转化为小写字母，小写字母换位大写字母，其余字符不变，谢啦

比如输入ASDfghJ，输出asdfGHj

Answer 1

Public string str(string strs)
{
string str=strs;
char[] ch = str.ToCharArray();
System.Text.RegularExpressions.Regex R = new System.Text.RegularExpressions.Regex("[A-Z]");
str = "";
foreach (char s in ch)
{
if (R.IsMatch(s.ToString()))
{
str += s.ToString().ToLower();
}
else
{
str += s.ToString().ToUpper();
}

}
return str;
}

已经验证，思路，把字符转化成 字符串数组，然后遍历，根据正则判断大小写

追问

能发完整的代码吗？
我这里显示错误
不包含适合于入口点的静态“Main”方法

追答

那是因为你，你是在控制台应用程序中调试，他是一个静态类吧，所以我的这个方法要加static关键字，

Public static string str(string strs)
{
...
}

Answer 2

也可以转换成ascii码再判断

string str = "abc123123按时efff打算DhhHHGjj";
StringBuilder sb = new StringBuilder();
str.ToList().ForEach(a => sb.Append(((short)a >= 65 && (short)a <= 90) ? ((char)((short)a + 32)).ToString() : (((short)a >= 97 && (short)a <= 122)) ? ((char)((short)a - 32)).ToString() : a.ToString()));
MessageBox.Show(sb.ToString());

Answer 3

private void button2_Click(object sender, EventArgs e)
       {
           string stringA = "ASDfghJ";
           string str = UpLowerConvert(stringA);
           MessageBox.Show(str);
       }
       /// <summary>
       /// 大小写互转
       /// </summary>
       /// <param name="chsstr"></param>
       /// <returns></returns>
       public static string UpLowerConvert(string chsstr)
       {
           string strRet = string.Empty;
           char[] ArrChar = chsstr.ToCharArray();
           foreach (char c in ArrChar)
           {
               strRet += SingleChs2UpLower(c.ToString());
           }
           return strRet;
       }
       /// <summary>
       /// 单个字母互转
       /// </summary>
       /// <param name="SingleChs"></param>
       /// <returns></returns>
       public static string SingleChs2UpLower(string SingleChs)
       {
           string strRtn = "";
           //将字母转为大/小写
           if (Regex.IsMatch(SingleChs, "[A-Z]"))
           {
               strRtn = SingleChs.ToLower();
           }
           else if (Regex.IsMatch(SingleChs, "[a-z]"))
           {
               strRtn = SingleChs.ToUpper();
           }
           return strRtn;
       }

Answer 4

string str="ABCabc";
MatchCollection MC = Regex.Matches(str, "[a-z]");
MatchCollection MC2 = Regex.Matches(str, "[A-Z]");
Encoding encode = Encoding.Unicode;
byte[] SelectedBuffer = encode.GetBytes(str);
foreach (Match M in MC)
{
    byte[] UBuffer = encode.GetBytes(M.Value.ToUpper());
    Array.Copy(UBuffer, 0, SelectedBuffer, M.Index << 1, UBuffer.Length);
}
foreach (Match M in MC2)
{
    byte[] UBuffer = encode.GetBytes(M.Value.ToLower());
    Array.Copy(UBuffer, 0, SelectedBuffer, M.Index << 1, UBuffer.Length);
}
str = encode.GetString(SelectedBuffer);

Answer 5

string temp = null;
string str = "aAbfdFCdfKF";
char[] lowChars = str.ToLower().ToCharArray();
char[] upChars = str.ToUpper().ToCharArray();
for (int i = 0; i < str.Length; i++)
{
temp += str[i] == lowChars[i] ? upChars[i] : lowChars[i];
}