Question

C# 在文本框输入的时候，怎么能让输入小写的字母，自动转换成大写的字母

我想在keypress实践中实现，

Answer 1

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;

}

试试这个
textBox2.Text = textBox1.Text.ToUpper(); //转换为 大写

Answer 2

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if((int)e.KeyChar>=97 && (int)e.KeyChar<=122) {
e.KeyChar = (char)((int)e.KeyChar - 32);
}
}