Нужно только числовые окна управления TextBox

Question

Я создаю диалог старой школы в C# с помощью System.Windows.Controls.TextBox. Есть ли простой способ ограничить ввод текста в этом поле только цифровым?

Спасибо!

Answer 1

Просто реализуйте обработчик события onkeyup, и если нажатая клавиша не является символом. IsDigit затем очистите его.

http://msdn.microsoft.com/en-us/library/system.windows.controls.textbox.onkeyup(VS.95).aspx

Answer 2

Вы могли бы рассмотреть возможность использования MaskedTextBox, установив Mask свойства соответственно.

Answer 3

Это выдержка из my answer to an earlier question.

---

Добавить этот класс в проект

using Microsoft.VisualBasic; 
using System; 
using System.Collections; 
using System.Collections.Generic; 
using System.Data; 
using System.Diagnostics; 
public class TextBoxFilter 
{ 
    [Flags()] 
    public enum Filters 
    { 
     None = 0, 
     Text = 1, 
     Numbers = 2, 
     AlphaNumeric = Filters.Text | Filters.Numbers, 
     Currency = 4, 
     All = Filters.Text | Filters.Numbers | Filters.Currency 
    } 

    Dictionary<TextBox, Filters> _keyFilter; 
    Dictionary<TextBox, string> _allowedKeys; 
    Dictionary<TextBox, string> _invalidKeys; 

    Dictionary<TextBox, Windows.Forms.KeyEventArgs> keyEventArgs; 
    private static string DecimalMark = Application.CurrentCulture.NumberFormat.NumberDecimalSeparator; 
    private static string NegativeMark = Application.CurrentCulture.NumberFormat.NegativeSign; 
    private static string CurrencySymb = Application.CurrentCulture.NumberFormat.CurrencySymbol; 

    private static string CurrencyDecimal = Application.CurrentCulture.NumberFormat.CurrencyDecimalSeparator; 

    public TextBoxFilter() 
    { 
     _keyFilter = new Dictionary<TextBox, Filters>(); 
     _allowedKeys = new Dictionary<TextBox, string>(); 
     _invalidKeys = new Dictionary<TextBox, string>(); 
     keyEventArgs = new Dictionary<TextBox, KeyEventArgs>(); 
    } 

//set & remove filter 

    public void SetTextBoxFilter(TextBox textBox, Filters filter) 
    { 
     SetTextBoxFilter(textBox, filter, AllowedKeys(textBox), InvalidKeys(textBox)); 
    } 

    public void SetTextBoxFilter(TextBox textBox, string allowedKeys) 
    { 
     SetTextBoxFilter(textBox, Strings.Filter(textBox), allowedKeys, InvalidKeys(textBox)); 
    } 


    public void SetTextBoxFilter(TextBox textBox, string allowedKeys, string invalidKeys) 
    { 
     SetTextBoxFilter(textBox, Strings.Filter(textBox), allowedKeys, invalidKeys); 
    } 


    public void SetTextBoxFilter(TextBox textBox, Filters filter, string allowedKeys, string invalidKeys) 
    { 
     if (!_keyFilter.ContainsKey(textBox)) { 
      //add the textbox and its filter if it does not exist in 
      //the collection of registered textboxes 
      _keyFilter.Add(textBox, filter); 
      _allowedKeys.Add(textBox, allowedKeys); 
      _invalidKeys.Add(textBox, invalidKeys); 
      keyEventArgs.Add(textBox, new System.Windows.Forms.KeyEventArgs(Keys.None)); 

      //add the event handlers 
      textBox.KeyDown += KeyDownUp; 
      textBox.KeyUp += KeyDownUp; 
      textBox.KeyPress += KeyPress; 
      textBox.Validating += Validating; 
      textBox.Disposed += Disposed; 

     } else { 
      //change the filter of the textbox if it exists in 
      //the collection of registered textboxes 
      _keyFilter(textBox) = filter; 
      _allowedKeys(textBox) = allowedKeys; 
      _invalidKeys(textBox) = invalidKeys; 
     } 
    } 

    public void RemoveTextBoxFilter(TextBox textBox) 
    { 
     if (_keyFilter.ContainsKey(textBox)) { 
      _keyFilter.Remove(textBox); 
      _allowedKeys.Remove(textBox); 
      _invalidKeys.Remove(textBox); 
      keyEventArgs.Remove(textBox); 

      textBox.KeyDown -= KeyDownUp; 
      textBox.KeyUp -= KeyDownUp; 
      textBox.KeyPress -= KeyPress; 
      textBox.Validating -= Validating; 
      textBox.Disposed -= Disposed; 
     } 
    } 

    public bool ContainsTextBox(TextBox textBox) 
    { 
     return _keyFilter.ContainsKey(textBox); 
    } 

//properties 

    public Filters Filter { 
     get { 
      if (ContainsTextBox(textBox)) { 
       return _keyFilter.Item[textBox]; 
      } else { 
       return Filters.None; 
      } 
     } 
     set { SetTextBoxFilter(textBox, value); } 
    } 

    public string AllowedKeys { 
     get { 
      if (ContainsTextBox(textBox)) { 
       return _allowedKeys(textBox); 
      } else { 
       return ""; 
      } 
     } 
     set { SetTextBoxFilter(textBox, this.Filter(textBox), value, this.InvalidKeys(textBox)); } 
    } 

    public string InvalidKeys { 
     get { 
      if (ContainsTextBox(textBox)) { 
       return _invalidKeys(textBox); 
      } else { 
       return ""; 
      } 
     } 
     set { SetTextBoxFilter(textBox, this.Filter(textBox), this.AllowedKeys(textBox), value); } 
    } 

//event handlers 

    private void Disposed(object sender, System.EventArgs e) 
    { 
     RemoveTextBoxFilter((TextBox)sender); 
    } 

    private void KeyDownUp(object sender, System.Windows.Forms.KeyEventArgs e) 
    { 
     //assign the modifiers 
     keyEventArgs((TextBox)sender) = e; 
    } 

    private void KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) 
    { 
     //ensure key pressed is in the allowed keys 

     object txt = (TextBox)sender; 
     object c = e.KeyChar; 
     bool allowKey = IsValidChar(txt, c, txt.SelectionStart); 


     //check for backspace & Ctrl combinations if the allowKey is still false 
     if (allowKey == false) { 
      if (keyEventArgs(txt).Control) { 
       //control modifier goes with A, X, C, V and Z for 
       //Select All, Cut, Copy, Paste and Undo respectively 
       object key = keyEventArgs(txt).KeyCode; 
       allowKey = (key == Keys.A || key == Keys.X || key == Keys.C || key == Keys.V || key == Keys.Z); 

      } else if (keyEventArgs(txt).KeyCode == Keys.Back) { 
       //allow the backspace key 
       allowKey = true; 
      } 
     } 


     //disable the key if it was not valid 
     if (!allowKey) { 
      e.Handled = true; 
      Interaction.Beep(); 
     } 
    } 

    private void Validating(object sender, System.ComponentModel.CancelEventArgs e) 
    { 
     object box = (TextBox)sender; 
     object boxFlags = _keyFilter(box); 

     //skip validation if the textbox allows all entries or there is no text 
     if (boxFlags == Filters.All | string.IsNullOrEmpty(box.Text)) 
      return; 

     //otherwise check the characters entered 
     object txtChars = box.Text.ToCharArray; 

     bool isValidEntry = false; 

     //check each caracter for an invalid entry 
     for (i = 0; i <= txtChars.Length - 1; i++) { 
      object c = txtChars(i); 
      isValidEntry = IsValidChar(box, txtChars(i), i); 

      if (!isValidEntry) { 
       box.Select(i, 1); 
       break; // TODO: might not be correct. Was : Exit For 
      } 
     } 

     if (!isValidEntry) 
      e.Cancel = true; 

     if (!isValidEntry) { 
      Interaction.MsgBox("The text entered is invalid for the format " + boxFlags.ToString + "." + !string.IsNullOrEmpty(_allowedKeys(box)) ? Constants.vbCrLf + "Additional Allowed Keys: " + _allowedKeys(box) : "" + !string.IsNullOrEmpty(_invalidKeys(box)) ? Constants.vbCrLf + "Additional Invalid Keys: " + _invalidKeys(box) : "", MsgBoxStyle.Critical, "Invalid Entry"); 
     } 
    } 

    private bool IsValidChar(TextBox textBox, char c, int charIndex) 
    { 
     //ensure key pressed is in the allowed keys 

     object pF = _keyFilter(textBox); 
     object aK = _allowedKeys(textBox); 
     object iK = _invalidKeys(textBox); 
     bool shouldAllow = false; 


     //if filter is set to all, return true unconditionally 
     if (pF == Filters.All) 
      return true; 


     //check preset filters 

     //check for text 
     if (EnumHasFlag(pF, Filters.Text)) { 
      if (!char.IsDigit(c)) { 
       shouldAllow = true; 
      } else { 
       //if the character is a digit, check for the number flag (AlphaNumerics) 
       if (EnumHasFlag(pF, Filters.Numbers)) { 
        shouldAllow = true; 
       } 
      } 

     } 

     //check for nubers 
     if (shouldAllow == false && EnumHasFlag(pF, Filters.Numbers)) { 
      if (char.IsDigit(c)) { 
       shouldAllow = true; 
      } else if (DecimalMark.Contains(c)) { 
       //allow the decimal if there is no decimal in the textbox's 
       //text or the selected text contains the mark 
       if (!textBox.Text.Substring(0, charIndex).Contains(c) || textBox.SelectedText.Contains(c)) { 
        shouldAllow = true; 
       } 
      } else if (NegativeMark.Contains(c) && (charIndex <= NegativeMark.IndexOf(c))) { 
       //allow the negative mark if we are at the start of the 
       //textbox 
       shouldAllow = true; 
      } 

     } 

     //check for currency 
     if (shouldAllow == false && EnumHasFlag(pF, Filters.Currency)) { 
      if (char.IsDigit(c)) { 
       shouldAllow = true; 
      } else if (CurrencyDecimal.Contains(c)) { 
       //allow the currency decimal mark if it does not exist in the 
       //textbox's text or the selected text contains the mark 
       if (!textBox.Text.Substring(0, charIndex).Contains(c) || textBox.SelectedText.Contains(c)) { 
        shouldAllow = true; 
       } 
      } else if (CurrencySymb.Contains(c) && (charIndex <= CurrencySymb.IndexOf(c))) { 
       //allow the currency symbol if we are in a valid position 
       shouldAllow = true; 
      } 

     } 



     //now check for extra allowed keys 
     if (!shouldAllow) { 
      shouldAllow = aK.Contains(c); 
     } 

     //and then check for extra invalid keys 
     if (shouldAllow && iK.Contains(c)) { 
      shouldAllow = false; 
     } 


     return shouldAllow; 
    } 

    [System.Diagnostics.DebuggerStepThrough()] 
    private bool EnumHasFlag(Enum value, Enum flag) 
    { 
     return (Convert.ToInt64(value) & Convert.ToInt64(flag)) == Convert.ToInt64(flag); 
    } 
} 

, а затем использовать его в виде следующим образом

public class Form1 
{ 


    TextBoxFilter filter = new TextBoxFilter(); 
    private void Form1_Load(object sender, System.EventArgs e) 
    { 
     filter.SetTextBoxFilter(TextBox1, TextBoxFilter.Filters.Numbers); 
    } 
    public Form1() 
    { 
     Load += Form1_Load; 
    } 
} 

Answer 4

также рассмотреть вопрос, нуждается ли ваш дизайн, чтобы ограничить ввод данных пользователя при вводе/вставить или если это нормально, просто преобразуйте ввод пользователя в число, когда он покидает текстовое поле.

Часто ограничительный подход сложнее делать (дело с запятые, точки, символы валют, пробелов и т.д. ... может быть огромная боль)

Этот метод становится столь же просто, как:

private void textBox1_Leave(object sender, EventArgs e) 
{ 
    textBox1.Text = VerifyNumeric(textBox1.Text); 
} 

private string VerifyNumeric(string text) 
{ 
    double value = 0; 
    double.TryParse(text, out value); 
    return value.ToString(); // could format here too. 
}