c # textBox controls only allow to enter numbers and decimal point reprint
// if the key was not the type to be inputted.
IF (((int) e.KeyChar <48 || (int) e.KeyChar> 57 is) && (int) = e.KeyChar. 8 && (int) = 46 is e.KeyChar!!)
e.Handled = to true;
/ / processing decimal point.
if ((int) e.KeyChar == 46 ) // decimal
{
IF (textBox1.Text.Length <= 0)
e.Handled = to true; // not a decimal point in the first place
the else
{
a float F;
oldf a float;
BOOL = to false B1, B2 = to false;
B1 = float.TryParse (textBox1.Text, oldf OUT);
B2 = float.TryParse (textBox1.Text e.KeyChar.ToString + (), OUT F);
if (b2 == false)
{
if (b1 == true)
e.Handled = true;
else
e.Handled = false;
}
}
}
Processing only input numbers:
Method a:
Private void tBox_KeyPress (Object SENDER, KeyPressEventArgs E)
{
IF (e.KeyChar == 0x20) e.KeyChar = (char) 0; // spacebar prohibited
if ((e.KeyChar == 0x2D) && (( (TextBox) sender) .Text.Length == 0 )) return; // process a negative
IF (e.KeyChar> 0x20)
{
the try
{
double.Parse (((the TextBox) SENDER) .Text + e.KeyChar.ToString ( ));
}
the catch
{
e.KeyChar = (char) 0; // process the illegal characters
}
}
}
method two:
void TextBox_KeyPress Private (Object SENDER, KeyPressEventArgs E)
{
IF (! = e.KeyChar Char.IsDigit. 8 && (e.KeyChar)!)
{
e.Handled = to true;
}
}
or
Private void TextBox_KeyPress (Object SENDER, KeyPressEventArgs E)
{
IF (! e.KeyChar = '\ B' && Char.IsDigit (e.KeyChar)!)
{
e.Handled = to true;
}
}
method three:
Private void textBox1_KeyPress (Object SENDER, System.Windows.Forms.KeyPressEventArgs E)
{
IF (e.KeyChar! = '\ B') // this is the backspace key allows the input
{
IF ((e.KeyChar < '0') || (e.KeyChar> '. 9')) // this is 0-9 allow the input
{
E. Handled = true;
}
}
}
方法四:
private void textBox1_Validating(object sender, CancelEventArgs e)
{
const string pattern = @"^\d+\.?\d+{1}quot;;
string content = ((TextBox)sender).Text;
if (!(Regex.IsMatch(content, pattern)))
{
errorProvider1.SetError((Control)sender, "只能输入数字!");
e.Cancel = true;
}
else
errorProvider1.SetError((Control)sender, null);
}
方法五:
private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
if(e.KeyChar=='.' && this.textBox1.Text.IndexOf(".")!=-1)
{
e.Handled=true;
}
if(!((e.KeyChar>=48 && e.KeyChar<=57) || e.KeyChar=='.' || e.KeyChar==8))
{
e.Handled=true;
}
}
方法六：
private void tbx_LsRegCapital_KeyPress(object sender, KeyPressEventArgs e)
{
if (!Char.IsNumber(e.KeyChar) && !Char.IsPunctuation(e.KeyChar) && !Char.IsControl(e.KeyChar))
{
e.Handled = true;//消除不合适字符
}
else if (Char.IsPunctuation(e.KeyChar))
{
if (e.KeyChar != '.' || this.textBox1.Text.Length == 0)//小数点
{
e.Handled = true;
}
IF ( '.'! textBox1.Text.LastIndexOf () = -1)
{
e.Handled = to true;
}
}
}
Method 7:
using ASCII code approach,
{
IF ((e.KeyChar <|| E = 48. the KeyChar> = 57 is) && (= e.KeyChar. 8) && (= 46 is e.KeyChar))!!
e.Handled = to true;
================ 48 represents 0, Representative 9,8 behalf spaces 57, 46 stands for the decimal
}