1. 添加 icon
选择图片并转换成ico格式:https://convertio.co/zh/download/8441dcb3979589069571b8c7295903474957c6/
然后右键属性中添加icon
2. Regex的replace方法替换,实现首字母大写
private void Add_Click(object sender, RoutedEventArgs e) { Button btn = (Button)sender; btn_content = (String)btn.Content; if (total.Equals("") || total.EndsWith('!') || total.EndsWith('.') || total.EndsWith('?')) { // capitalize the first letter firstContent = btn_content[1].ToString().ToUpper(); // original first letter that need to be replaced Regex regex = new Regex(btn_content[1].ToString()); // only replace once btn_content = regex.Replace(btn_content, firstContent, 1); } total += btn_content; Result.Content = total; }