编写一个C#代码,返回一个字符串,每个字母都反转

Question

我们在C#中有任何适当的功能吗？

 private void button1_Click(object sender, EventArgs e)
 {
     string s1 = textBox1.Text;
 }

Answer 1

string s1 = new string(
    textBox1.Text.Select(ch => char.IsLetter(ch) ? (char.IsUpper(ch) ?
                      char.ToLower(ch) : char.ToUpper(ch)) : ch).ToArray());