WPF文本框中的验证

只能使用文本框上的附加属性将输入限制为数字。定义一次附加属性(即使在单独的dll中),并在任何文本框中使用它。附属性如下:

   using System;
   using System.Windows;
   using System.Windows.Controls;
   using System.Windows.Input;

   /// <summary>
   /// Class that provides the TextBox attached property
   /// </summary>
   public static class TextBoxService
   {
      /// <summary>
      /// TextBox Attached Dependency Property
      /// </summary>
      public static readonly DependencyProperty IsNumericOnlyProperty = DependencyProperty.RegisterAttached(
         "IsNumericOnly",
         typeof(bool),
         typeof(TextBoxService),
         new UIPropertyMetadata(false, OnIsNumericOnlyChanged));

      /// <summary>
      /// Gets the IsNumericOnly property.  This dependency property indicates the text box only allows numeric or not.
      /// </summary>
      /// <param name="d"><see cref="DependencyObject"/> to get the property from</param>
      /// <returns>The value of the StatusBarContent property</returns>
      public static bool GetIsNumericOnly(DependencyObject d)
      {
         return (bool)d.GetValue(IsNumericOnlyProperty);
      }

      /// <summary>
      /// Sets the IsNumericOnly property.  This dependency property indicates the text box only allows numeric or not.
      /// </summary>
      /// <param name="d"><see cref="DependencyObject"/> to set the property on</param>
      /// <param name="value">value of the property</param>
      public static void SetIsNumericOnly(DependencyObject d, bool value)
      {
         d.SetValue(IsNumericOnlyProperty, value);
      }

      /// <summary>
      /// Handles changes to the IsNumericOnly property.
      /// </summary>
      /// <param name="d"><see cref="DependencyObject"/> that fired the event</param>
      /// <param name="e">A <see cref="DependencyPropertyChangedEventArgs"/> that contains the event data.</param>
      private static void OnIsNumericOnlyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
      {
         bool isNumericOnly = (bool)e.NewValue;

         TextBox textBox = (TextBox)d;

         if (isNumericOnly)
         {
            textBox.PreviewTextInput += BlockNonDigitCharacters;
            textBox.PreviewKeyDown += ReviewKeyDown;
         }
         else
         {
            textBox.PreviewTextInput -= BlockNonDigitCharacters;
            textBox.PreviewKeyDown -= ReviewKeyDown;
         }
      }

      /// <summary>
      /// Disallows non-digit character.
      /// </summary>
      /// <param name="sender">The source of the event.</param>
      /// <param name="e">An <see cref="TextCompositionEventArgs"/> that contains the event data.</param>
      private static void BlockNonDigitCharacters(object sender, TextCompositionEventArgs e)
      {
         foreach (char ch in e.Text)
         {
            if (!Char.IsDigit(ch))
            {
               e.Handled = true;
            }
         }
      }

      /// <summary>
      /// Disallows a space key.
      /// </summary>
      /// <param name="sender">The source of the event.</param>
      /// <param name="e">An <see cref="KeyEventArgs"/> that contains the event data.</param>
      private static void ReviewKeyDown(object sender, KeyEventArgs e)
      {
         if (e.Key == Key.Space)
         {
            // Disallow the space key, which doesn't raise a PreviewTextInput event.
            e.Handled = true;
         }
      }
   }

以下是如何使用它(用您自己的命名空间替换“controls”):

<TextBox controls:TextBoxService.IsNumericOnly="True" />

您可以在绑定中进行验证

<TextBox>
         <TextBox.Text>
              <Binding Path="CategoriaSeleccionada.ColorFondo"
                       UpdateSourceTrigger="PropertyChanged">
                     <Binding.ValidationRules>
                           <utilities:RGBValidationRule />
                     </Binding.ValidationRules>
               </Binding>
         </TextBox.Text>
</TextBox>

看看这个(我的程序)示例,您将验证放在绑定中,如下所示。使用UpdateSourceTrigger,您可以更改绑定何时更新(丢失焦点,每次更改中…)

好吧,验证是一个类,我给你举个例子:

class RGBValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo)
    {
        // Here you make your validation using the value object.
        // If you want to check if the object is only numbers you can
        // Use some built-in method
        string blah = value.ToString();
        int num;
        bool isNum = int.TryParse(blah, out num);

        if (isNum) return new ValidationResult(true, null);
        else return new ValidationResult(false, "It's no a number");
    }
}

简而言之,在该方法内执行该操作并返回一个新的validationresult。第一个参数是bool,如果验证良好,则为true,否则为false。第二个参数只是一条信息消息。

我认为这是文本框验证的基础。

希望这有帮助。

编辑:对不起,我不知道vb.net,但我认为C代码非常简单。