Numeric TextBox In C#

Question

How to add a seprate Text Box That allows only Numeric Values.

Alan · Answer

I'd check out both the MaskedTextBox and the NumericUpDown controls to see if they'll do what you want : http://msdn.microsoft.com/en-us/library/system.windows.forms.maskedtextbox.aspx http://msdn.microsoft.com/en-us/library/system.windows.forms.numericupdown.aspx Also, if you want to restrict the input of a standard TextBox (including characters pasted in) to integers, then here's some code I wrote recently to do this (set the MaxLength property to whatever you want first): private bool reentry = false; private void textBox1_TextChanged(object sender, EventArgs e) { if (reentry) { reentry = false; return; } if (textBox1.Text.Length == 0) return; int index = textBox1.SelectionStart; int removals = 0; List chars = new List (textBox1.Text); for (int i = chars.Count - 1; i >= 0; i--) { if (chars[i] 57) { chars.RemoveAt(i); removals++; } } if (chars.Count == 0) { reentry = true; textBox1.Text = ""; reentry = false; return; } if (removals > 0) { reentry = true; textBox1.Text = new string(chars.ToArray()); reentry = false; } int len = textBox1.Text.Length; if (chars[0] == '0' && chars.Count > 1) { reentry = true; textBox1.Text = textBox1.Text.TrimStart('0'); reentry = false; int len2 = textBox1.Text.Length; if (len2 == 0) { reentry = true; textBox1.Text = "0"; reentry = false; len2 = 1; } removals += len - len2; } if (removals == 0) return; textBox1.SelectionStart = Math.Min(Math.Max(index - removals, 0), textBox1.Text.Length + 1); }