如何只允许文本框中的数字？

Question

I Want to enter text box just to numbers

this type = "number" dont block lettrs at client side

@Html.TextBoxFor(m => m.kidsNumber, 
                      new { @class = "textBox1", 
                             @type = "number", 
                             @min = "1", 
                             @max = "30", 
                             @id = "kidsNumber"})

This doesnt block letters at client side and server side

[Range(1, 30, ErrorMessage = "1-30")]
[RegularExpression("([0-3][0-9])", ErrorMessage = "1-30")]
public string kidsNumber { get; set; }

Answer 1

Not sure I understand your question, honestly. An input with type "number" will block the input of anything but a number in browsers that support it . Not all browsers support the newer HTML5 input types, and in those that don't, the field will fallback to a regular text input that will accept any character. And, of course, it doesn't stop people from jacking with your code using the browser developer tools and such and changing the type from number to text to allow any character.

If you want to have a little more control, you can attach a JavaScript event handler that listens to an event like keydown on the field and then regex replace anything that's not a digit, but of course, JavaScript can be disabled or otherwise tampered with.

Really, your best bet at preventing non-numeric input is to change your property's type from string to something like int . If a number can't be parsed from the posted data by the modelbinder, the field will be set to 0 (as the default for an int) or null if you make it a nullable int ( int? ). Either way, the validation for your Range attribute would kick in and present an error to the user.