C# 仅输入数字和控制按钮

我想用任意值输入工资：

550,49

，

2222,12

，

9,3

等等。但是需要像这样使用控制按钮：

，

，

退格

，

ctrl+c

，

ctrl+v

，

ctrl+a

Salary

是

TextBox

带有

ShortcutsEnabled=true

和事件：

private void TbSalary_KeyPress(object sender, KeyPressEventArgs e)
{
    char number = e.KeyChar;
    if ((e.KeyChar <= 47 || e.KeyChar >= 58) && number != 8 && number != 44) 
         //digits, BackSpace and ,
    {
        e.Handled = true;
    }
}

请不要使用像

47

这样的神奇数字，让我们使用字符。我们应该允许这些字符：

• '0'..'9'

  范围（数字）
• 用于

  选项卡

  ，

  退格

  等的控制字符（位于空格

  '

  下方）
• “，”（逗号）作为十进制分隔符

所有其他角色都应该被禁止

代码：

private void TbSalary_KeyPress(object sender, KeyPressEventArgs e)
{
    char number = e.KeyChar;
    TextBox box = sender as TextBox;

    if (number >= '0' && number <= '9' || number < ' ')
        return; // numbers as well as backspaces, tabs: business as usual
    else if (number == ',') {  
        // We don't want to allow several commas, right?
        int p = box.Text.IndexOf(',');

        // So if we have a comma already...
        if (p >= 0) { 
            // ... we don't add another one
            e.Handled = true;

            // but place caret after the comma position
            box.SelectionStart = p + 1;
            box.SelectionLength = 0;  
        }  
        else if (box.SelectionStart == 0) {
            // if we don't have comma and we try to add comma at the 1st position 
            e.Handled = true;

            // let's add it as "0,"
            box.Text = "0," + box.Text.Substring(box.SelectionLength);
            box.SelectionStart = 2;
       } 
    }
    else  
        e.Handled = true; // all the other characters (like '+', 'p') are banned
}

---

你能告诉我为什么在我的情况下，

Ctrl

组合被阻止了吗？对于完全控制，当逗号强制第一个时，缺少大小写。错误或暗示

0，***

@查看：如果您想允许所有控制键（如

backspace

，

ctrl+v

等），您应该允许控制字符（位于空格以下）：

number<'

@查看：当我们位于第一个位置并按逗号并想要查看

“0，…”

而不是

，…”

（参见我的编辑）看看我试图禁止在小数点后输入两个以上的数字（更新帖子）。@查看：对不起，我不买它。如果我有

“123456,78”

插入符号在

2

-

“12 | 3456,78”之后怎么办“

然后我按

0

？如果开始优化解决方案，则应使用

box.SelectionStart

和

box.SelectionLength

操作。在您的情况下：如果逗号存在且不在选择范围内，如果插入符号位置在逗号之后，则。。。

private void TbSalary_KeyPress(object sender, KeyPressEventArgs e)
{
    char number = e.KeyChar;
    TextBox box = sender as TextBox;

    if (number >= '0' && number <= '9' || number < ' ')
        return; // numbers as well as backspaces, tabs: business as usual
    else if (number == ',') {  
        // We don't want to allow several commas, right?
        int p = box.Text.IndexOf(',');

        // So if we have a comma already...
        if (p >= 0) { 
            // ... we don't add another one
            e.Handled = true;

            // but place caret after the comma position
            box.SelectionStart = p + 1;
            box.SelectionLength = 0;  
        }  
        else if (box.SelectionStart == 0) {
            // if we don't have comma and we try to add comma at the 1st position 
            e.Handled = true;

            // let's add it as "0,"
            box.Text = "0," + box.Text.Substring(box.SelectionLength);
            box.SelectionStart = 2;
       } 
    }
    else  
        e.Handled = true; // all the other characters (like '+', 'p') are banned
}

private void TbSalary_TextChanged(object sender, EventArgs e) {
  TextBox box = sender as TextBox;

  StringBuilder sb = new StringBuilder();

  bool hasComma = false;

  foreach (var c in box.Text)
    if (c >= '0' && c <= '9')
      sb.Append(c);
    else if (c == ',' && !hasComma) {
      hasComma = true;

      if (sb.Length <= 0) // we don't start from comma
        sb.Append('0');

      sb.Append(c);
    }

  string text = sb.ToString();

  if (!text.Equals(box.Text))
    box.Text = text;
}