C# private void KeyUP_COMobject sender KeyPressEventArgs e if !charIsLetterOrDigiteKeyChar eKeyChar == b eKeyChar == C eKeyChar == O eKeyChar == M e

// 当串口号文本框有按键按下时触发 private void KeyUP_COM(object sender, KeyPressEventArgs e) { // 判断按下的按键是否为字母或数字或退格或C或O或M if (!(char.IsLetterOrDigit(e.KeyChar) || e.KeyChar == '\b' || e.KeyChar == 'C' || e.KeyChar == 'O' || e.KeyChar == 'M')) { // 如果按键不符合要求，则标记文本框内容已被修改 e.Handled = true; isTextChanged_COM = true; } else { e.Handled = false; } }

// 当串口号文本框内容发生改变时触发 private void TextChanged_COM(object sender, EventArgs e) { if (isTextChanged_COM) { // 如果文本框内容已被修改，则将文本框内容转换为大写字母 isTextChanged_COM = false; TextBox t = sender as TextBox; t.Text = t.Text.ToUpper(); // 将光标移动到文本框末尾 t.SelectionStart = t.Text.Trim().Length; } }