字母大小写互换[C#]

 

现思路如下：

1，判断是大写还是小写 ，这通过字符的比较即可得

2，对字符的ascci码加或减（‘a’- ‘A’= 32）实现大小写转化

 private void button1_Click(object sender, System.EventArgs e)
 {
  string inputStr = textBox1.Text;
  char[] outputStr = new char[inputStr.Length];
  string s = string.Empty;
  for(int i = 0; i < textBox1.Text.Length; i ++)
  {
  if(inputStr[i] >= ?a? && inputStr[i] <= ?z?)
   outputStr[i] = (char)(inputStr[i]- (?a? - ?A?));
  if(inputStr[i] >= ?A? && inputStr[i] <= ?Z?)
   outputStr[i] = (char)(inputStr[i] + (?a? - ?A?));
  }
  for(int i = 0; i < outputStr.Length; i ++)
  {
  s = s + outputStr[i].ToString();
  }
  label1.Text = s;
  
 }