How can I set Regular Expression on TextBox?

问题

How can I set a regular expression on WPF TextBox? I want the textbox to accept input in some predefined format. Is it possible?

回答1:

You have several options:

You can create a ValidationRule subclass (see below) and add it to your Binding's Validators property
You can set a ValidationCallback on your bound property, throw an exception if the value is wrong, and use this technique for easily showing validation errors
You can create an attached property that registers an event handler for the TextBox.TextChanged property and implement your own validation error notification mechanism
You can use a normal TextBox with an TextBox_Changed handler in code behind
You can handle PreviewKeyDown and PreviewTextInput from an attached property as shown here
You can use a masked text box as mentioned by Jan

For arbitrary regexes I would generally use WPF's built-in validation features or do the validation on the bound property. For specific needs the PreviewKeyDown/PreviewTextInput or masked text box might be better.

Here is how you would create a ValidationRule subclass:

public class RegexValidationRule : ValidationRule
{
  ... // Declare Regex property and Message property

  public override ValidationResult Validate(object value, CultureInfo cultureInfo)
  {
    if(Regex.IsMatch((string)value))
      return ValidationResult.ValidResult;
    else
      return new ValidationResult(false, Message);
  }
}

回答2:

Either you can check at the changed event or you could use what's called a masked textbox.

来源：https://stackoverflow.com/questions/1734511/how-can-i-set-regular-expression-on-textbox

标签

wpf

regex

textbox