我一直致力于一个组件的集合来完成WinForms中缺失的东西，这里是:高级表单

特别地，这是一个正则文本框类

/// <summary>Represents a Windows text box control that only allows input that matches a regular expression.</summary>
public class RegexTextBox : TextBox
{
    [NonSerialized]
    string lastText;

    /// <summary>A regular expression governing the input allowed in this text field.</summary>
    [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    public virtual Regex Regex { get; set; }

    /// <summary>A regular expression governing the input allowed in this text field.</summary>
    [DefaultValue(null)]
    [Category("Behavior")]
    [Description("Sets the regular expression governing the input allowed for this control.")]
    public virtual string RegexString {
        get {
            return Regex == null ? string.Empty : Regex.ToString();
        }
        set {
            if (string.IsNullOrEmpty(value))
                Regex = null;
            else
                Regex = new Regex(value);
        }
    }

    protected override void OnTextChanged(EventArgs e) {
        if (Regex != null && !Regex.IsMatch(Text)) {
            int pos = SelectionStart - Text.Length + (lastText ?? string.Empty).Length;
            Text = lastText;
            SelectionStart = Math.Max(0, pos);
        }

        lastText = Text;

        base.OnTextChanged(e);
    }
}

简单地添加像myNumbericTextBox这样的东西。RegexString = "^(\\d+|)$";应该足够了。

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

最简单粗暴的方法是使用组合框而不是带有只读的文本框。当然，只有当你希望用户使用一个合理的整数集，而不是试图接近无穷大时，它才有用。

允许一行代码小数点

    private void txtQty_KeyPress(object sender, KeyPressEventArgs e)
    {
        e.Handled =  e.KeyChar != '.' && !char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar);
    }

private void txt3_KeyPress(object sender, KeyPressEventArgs e)
{
    for (int h = 58; h <= 127; h++)
    {
        if (e.KeyChar == h)             //58 to 127 is alphabets tat will be         blocked
        {
            e.Handled = true;
        }
    }
    for(int k=32;k<=47;k++)
    {
        if (e.KeyChar == k)              //32 to 47 are special characters tat will 
        {                                  be blocked
            e.Handled = true;
        }
    }
}

试试这个很简单

这可能有用。它允许“真实”数值，包括正确的小数点和前面的加号或减号。从相关的KeyPress事件中调用它。

       private bool IsOKForDecimalTextBox(char theCharacter, TextBox theTextBox)
    {
        // Only allow control characters, digits, plus and minus signs.
        // Only allow ONE plus sign.
        // Only allow ONE minus sign.
        // Only allow the plus or minus sign as the FIRST character.
        // Only allow ONE decimal point.
        // Do NOT allow decimal point or digits BEFORE any plus or minus sign.

        if (
            !char.IsControl(theCharacter)
            && !char.IsDigit(theCharacter)
            && (theCharacter != '.')
            && (theCharacter != '-')
            && (theCharacter != '+')
        )
        {
            // Then it is NOT a character we want allowed in the text box.
            return false;
        }



        // Only allow one decimal point.
        if (theCharacter == '.'
            && theTextBox.Text.IndexOf('.') > -1)
        {
            // Then there is already a decimal point in the text box.
            return false;
        }

        // Only allow one minus sign.
        if (theCharacter == '-'
            && theTextBox.Text.IndexOf('-') > -1)
        {
            // Then there is already a minus sign in the text box.
            return false;
        }

        // Only allow one plus sign.
        if (theCharacter == '+'
            && theTextBox.Text.IndexOf('+') > -1)
        {
            // Then there is already a plus sign in the text box.
            return false;
        }

        // Only allow one plus sign OR minus sign, but not both.
        if (
            (
                (theCharacter == '-')
                || (theCharacter == '+')
            )
            && 
            (
                (theTextBox.Text.IndexOf('-') > -1)
                ||
                (theTextBox.Text.IndexOf('+') > -1)
            )
            )
        {
            // Then the user is trying to enter a plus or minus sign and
            // there is ALREADY a plus or minus sign in the text box.
            return false;
        }

        // Only allow a minus or plus sign at the first character position.
        if (
            (
                (theCharacter == '-')
                || (theCharacter == '+')
            )
            && theTextBox.SelectionStart != 0
            )
        {
            // Then the user is trying to enter a minus or plus sign at some position 
            // OTHER than the first character position in the text box.
            return false;
        }

        // Only allow digits and decimal point AFTER any existing plus or minus sign
        if  (
                (
                    // Is digit or decimal point
                    char.IsDigit(theCharacter)
                    ||
                    (theCharacter == '.')
                )
                &&
                (
                    // A plus or minus sign EXISTS
                    (theTextBox.Text.IndexOf('-') > -1)
                    ||
                    (theTextBox.Text.IndexOf('+') > -1)
                )
                &&
                    // Attempting to put the character at the beginning of the field.
                    theTextBox.SelectionStart == 0
            )
        {
            // Then the user is trying to enter a digit or decimal point in front of a minus or plus sign.
            return false;
        }

        // Otherwise the character is perfectly fine for a decimal value and the character
        // may indeed be placed at the current insertion position.
        return true;
    }