在文本框中简单地使用此代码:

private void textBox1_TextChanged(object sender, EventArgs e)
{

    double parsedValue;

    if (!double.TryParse(textBox1.Text, out parsedValue))
    {
        textBox1.Text = "";
    }
}

我在CodePlex上做了一些东西。

它通过拦截TextChanged事件来工作。如果结果是一个好的数字，它将被存储。如果是错误的，最后的好值将恢复。源代码有点太大，不适合在这里发布，但这里有一个指向处理此逻辑核心的类的链接。

我喜欢简洁的代码

    private void xmm_textbox_KeyPress(object sender, KeyPressEventArgs e) {
        double x;
        e.Handled = !double.TryParse(((TextBox)sender).Text, out x);
    }

这是一个简单的独立的Winforms自定义控件，从标准的TextBox派生而来，只允许System。Int32输入(它可以很容易地适用于其他类型，如System。Int64,等等)。它支持复制/粘贴操作和负数:

public class Int32TextBox : TextBox
{
    protected override void OnKeyPress(KeyPressEventArgs e)
    {
        base.OnKeyPress(e);

        NumberFormatInfo fi = CultureInfo.CurrentCulture.NumberFormat;

        string c = e.KeyChar.ToString();
        if (char.IsDigit(c, 0))
            return;

        if ((SelectionStart == 0) && (c.Equals(fi.NegativeSign)))
            return;

        // copy/paste
        if ((((int)e.KeyChar == 22) || ((int)e.KeyChar == 3))
            && ((ModifierKeys & Keys.Control) == Keys.Control))
            return;

        if (e.KeyChar == '\b')
            return;

        e.Handled = true;
    }

    protected override void WndProc(ref System.Windows.Forms.Message m)
    {
        const int WM_PASTE = 0x0302;
        if (m.Msg == WM_PASTE)
        {
            string text = Clipboard.GetText();
            if (string.IsNullOrEmpty(text))
                return;

            if ((text.IndexOf('+') >= 0) && (SelectionStart != 0))
                return;

            int i;
            if (!int.TryParse(text, out i)) // change this for other integer types
                return;

            if ((i < 0) && (SelectionStart != 0))
                return;
        }
        base.WndProc(ref m);
    }

2017年更新:我的第一个答案有一些问题:

你可以输入一个比给定类型的整数更长的值(例如2147483648大于Int32.MaxValue); 更一般地说，对于输入的结果没有真正的验证; 它只处理int32，你必须写特定的TextBox衍生控件为每种类型(Int64等)

所以我提出了另一个更通用的版本，它仍然支持复制/粘贴，+和-号等。

public class ValidatingTextBox : TextBox
{
    private string _validText;
    private int _selectionStart;
    private int _selectionEnd;
    private bool _dontProcessMessages;

    public event EventHandler<TextValidatingEventArgs> TextValidating;

    protected virtual void OnTextValidating(object sender, TextValidatingEventArgs e) => TextValidating?.Invoke(sender, e);

    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);
        if (_dontProcessMessages)
            return;

        const int WM_KEYDOWN = 0x100;
        const int WM_ENTERIDLE = 0x121;
        const int VK_DELETE = 0x2e;

        bool delete = m.Msg == WM_KEYDOWN && (int)m.WParam == VK_DELETE;
        if ((m.Msg == WM_KEYDOWN && !delete) || m.Msg == WM_ENTERIDLE)
        {
            DontProcessMessage(() =>
            {
                _validText = Text;
                _selectionStart = SelectionStart;
                _selectionEnd = SelectionLength;
            });
        }

        const int WM_CHAR = 0x102;
        const int WM_PASTE = 0x302;
        if (m.Msg == WM_CHAR || m.Msg == WM_PASTE || delete)
        {
            string newText = null;
            DontProcessMessage(() =>
            {
                newText = Text;
            });

            var e = new TextValidatingEventArgs(newText);
            OnTextValidating(this, e);
            if (e.Cancel)
            {
                DontProcessMessage(() =>
                {
                    Text = _validText;
                    SelectionStart = _selectionStart;
                    SelectionLength = _selectionEnd;
                });
            }
        }
    }

    private void DontProcessMessage(Action action)
    {
        _dontProcessMessages = true;
        try
        {
            action();
        }
        finally
        {
            _dontProcessMessages = false;
        }
    }
}

public class TextValidatingEventArgs : CancelEventArgs
{
    public TextValidatingEventArgs(string newText) => NewText = newText;
    public string NewText { get; }
}

对于Int32，你可以从它导出，像这样:

public class Int32TextBox : ValidatingTextBox
{
    protected override void OnTextValidating(object sender, TextValidatingEventArgs e)
    {
        e.Cancel = !int.TryParse(e.NewText, out int i);
    }
}

或w/o派生，使用新的textvalididating事件，像这样:

var vtb = new ValidatingTextBox();
...
vtb.TextValidating += (sender, e) => e.Cancel = !int.TryParse(e.NewText, out int i);

但它的优点是它适用于任何字符串和任何验证例程。

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。

WPF的工作解决方案&一个简单的TextChangedEventArgs。

private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
    var TextBox = (sender as TextBox);

    // if not a numeric value, remove news characters
    if (Regex.IsMatch(TextBox.Text, "[^0-9]"))
    {
        foreach (TextChange Change in e.Changes)
        {
            TextBox.Text = TextBox.Text.Remove(Change.Offset, Change.AddedLength);

            TextBox.CaretIndex = Change.Offset;
        }
    }
}