在按钮点击，你可以检查文本框的文本循环:

char[] c = txtGetCustomerId.Text.ToCharArray();
bool IsDigi = true;

for (int i = 0; i < c.Length; i++)
     {
       if (c[i] < '0' || c[i] > '9')
      { IsDigi = false; }
     }
 if (IsDigi)
    { 
     // do something
    }

尝试一个MaskedTextBox。它采用一种简单的掩码格式，这样你就可以将输入限制为数字或日期之类的。

两个选择:

Use a NumericUpDown instead. NumericUpDown does the filtering for you, which is nice. Of course it also gives your users the ability to hit the up and down arrows on the keyboard to increment and decrement the current value. Handle the appropriate keyboard events to prevent anything but numeric input. I've had success with this two event handlers on a standard TextBox: private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.')) { e.Handled = true; } // only allow one decimal point if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1)) { e.Handled = true; } }

您可以删除'的支票。如果你的文本框不允许小数点，'(和后续检查不止一个'.')。你也可以添加一个检查'-'如果你的文本框应该允许负值。

如果您想限制用户的位数，请使用:textBox1。MaxLength = 2;//这将允许用户只输入2位数字

这是用.NET 5/Core来实现的一种很好很短的方法

private void textBox1_KeyDown(object sender, KeyEventArgs e) {
  if (e.KeyData != Keys.Back)
    e.SuppressKeyPress = !int.TryParse(Convert.ToString((char) e.KeyData), out int _);
}

编辑:增加了退格键的支持

这是我的方法:

using linq (easy to modify filter) copy/paste proof code keeps caret position when you press a forbidden character accepts left zeroes and any size numbers private void numeroCuenta_TextChanged(object sender, EventArgs e) { string org = numeroCuenta.Text; string formated = string.Concat(org.Where(c => (c >= '0' && c <= '9'))); if (formated != org) { int s = numeroCuenta.SelectionStart; if (s > 0 && formated.Length > s && org[s - 1] != formated[s - 1]) s--; numeroCuenta.Text = formated; numeroCuenta.SelectionStart = s; } }

你可以使用TextChanged/ Keypress事件，使用正则表达式过滤数字，并采取一些行动。