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。

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。

似乎目前对这个问题的许多答案都是手动解析输入文本。如果你正在寻找一个特定的内置数字类型(例如int或double)，为什么不只是将工作委托给该类型的TryParse方法?例如:

public class IntTextBox : TextBox
{
    string PreviousText = "";
    int BackingResult;

    public IntTextBox()
    {
        TextChanged += IntTextBox_TextChanged;
    }

    public bool HasResult { get; private set; }

    public int Result
    {
        get
        {
            return HasResult ? BackingResult : default(int);
        }
    }

    void IntTextBox_TextChanged(object sender, EventArgs e)
    {
        HasResult = int.TryParse(Text, out BackingResult);

        if (HasResult || string.IsNullOrEmpty(Text))
        {
            // Commit
            PreviousText = Text;
        }
        else
        {
            // Revert
            var changeOffset = Text.Length - PreviousText.Length;
            var previousSelectionStart =
                Math.Max(0, SelectionStart - changeOffset);

            Text = PreviousText;
            SelectionStart = previousSelectionStart;
        }
    }
}

如果你想要更通用但仍然兼容Visual Studio的设计器:

public class ParsableTextBox : TextBox
{
    TryParser BackingTryParse;
    string PreviousText = "";
    object BackingResult;

    public ParsableTextBox()
        : this(null)
    {
    }

    public ParsableTextBox(TryParser tryParse)
    {
        TryParse = tryParse;

        TextChanged += ParsableTextBox_TextChanged;
    }

    public delegate bool TryParser(string text, out object result);

    public TryParser TryParse
    {
        set
        {
            Enabled = !(ReadOnly = value == null);

            BackingTryParse = value;
        }
    }

    public bool HasResult { get; private set; }

    public object Result
    {
        get
        {
            return GetResult<object>();
        }
    }

    public T GetResult<T>()
    {
        return HasResult ? (T)BackingResult : default(T);
    }

    void ParsableTextBox_TextChanged(object sender, EventArgs e)
    {
        if (BackingTryParse != null)
        {
            HasResult = BackingTryParse(Text, out BackingResult);
        }

        if (HasResult || string.IsNullOrEmpty(Text))
        {
            // Commit
            PreviousText = Text;
        }
        else
        {
            // Revert
            var changeOffset = Text.Length - PreviousText.Length;
            var previousSelectionStart =
                Math.Max(0, SelectionStart - changeOffset);

            Text = PreviousText;
            SelectionStart = previousSelectionStart;
        }
    }
}

最后，如果你想要完全通用的东西，不关心Designer支持:

public class ParsableTextBox<T> : TextBox
{
    TryParser BackingTryParse;
    string PreviousText;
    T BackingResult;

    public ParsableTextBox()
        : this(null)
    {
    }

    public ParsableTextBox(TryParser tryParse)
    {
        TryParse = tryParse;

        TextChanged += ParsableTextBox_TextChanged;
    }

    public delegate bool TryParser(string text, out T result);

    public TryParser TryParse
    {
        set
        {
            Enabled = !(ReadOnly = value == null);

            BackingTryParse = value;
        }
    }

    public bool HasResult { get; private set; }

    public T Result
    {
        get
        {
            return HasResult ? BackingResult : default(T);
        }
    }

    void ParsableTextBox_TextChanged(object sender, EventArgs e)
    {
        if (BackingTryParse != null)
        {
            HasResult = BackingTryParse(Text, out BackingResult);
        }

        if (HasResult || string.IsNullOrEmpty(Text))
        {
            // Commit
            PreviousText = Text;
        }
        else
        {
            // Revert
            var changeOffset = Text.Length - PreviousText.Length;
            var previousSelectionStart =
                Math.Max(0, SelectionStart - changeOffset);

            Text = PreviousText;
            SelectionStart = previousSelectionStart;
        }
    }
}

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; } }

故障安全和简单的“递归”方法，可用于多个文本框。

它可以阻止错误的键盘输入字符，也可以粘贴值等。它只接受整数，最大数字长度是字符串类型的最大长度(它是int，真的很长!)

public void Check_If_Int_On_TextChanged(object sender, EventArgs e)
{
   // This method checks that each inputed character is a number. Any non-numeric
   // characters are removed from the text

   TextBox textbox = (TextBox)sender;

   // If the text is empty, return
   if (textbox.Text.Length == 0) { return; }

   // Check the new Text value if it's only numbers
   byte parsedValue;
   if (!byte.TryParse(textbox.Text[(textbox.Text.Length - 1)].ToString(), out parsedValue))
   {
      // Remove the last character as it wasn't a number
      textbox.Text = textbox.Text.Remove((textbox.Text.Length - 1));

      // Move the cursor to the end of text
      textbox.SelectionStart = textbox.Text.Length;
    }
 }

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