asp.net mvc validation must be a number custom error

I am new to asp.net and I have a problem. When the users insert in a 开发者_如何转开发editor for a decimal field something other than numbers, they get an error "Field name" is not a number. But I don't want them to receive this message I want them to receive another message. I have no problem with this with required and range validators. Is there any way for me to do this?

I am not refering necessarily to changing the culture just displaying another message.

Thanks.

Hope I understand your, to change RangeValidator ErrorMessage just initialize ErrorMessage parameter:

[Range(0, 100, ErrorMessage = "Some another error message insert here!")]
[RegularExpression("\d", ErrorMessage = "!!!")]
public decimal DecimalField { get; set; }

This is the actual answer:

Create a class CustomClientDataTypeModelValidatorProvider. Copy the code from the MVC sources. Change the method MakeErrorString to output the appropiate message like this:

private static string MakeErrorString(string displayName)
{
    return string.Format(
        CultureInfo.CurrentCulture, 
        Core.Resources.Errors.EroareNuENr, 
        displayName);
}

I couldn't find a way not to copy the code just extend it as it uses this static method. If anyone knows this please tell me.

Then, in global.asax, I wrote this:

var cdProvider = ModelValidatorProviders.Providers.SingleOrDefault(p => p.GetType().Equals(typeof(ClientDataTypeModelValidatorProvider)));
            if(cdProvider != null)
            {
                ModelValidatorProviders.Providers.Remove(cdProvider);
                ModelValidatorProviders.Providers.Add(
                        new CustomClientDataTypeModelValidatorProvider());
            }

so that the flow would actually be routed to my class and not the class in the asp.net MVC dll

I got the idea from here:

Unfortunately this is is not a trivial task. However you can try the following hack... Better to do this only on essential fields, as this is more code to maintain.

In the controller's action method

if(ModelState.IsValid)
{
  // code
}
else
{
  if (ModelState["YourField"].Errors.Count > 0)
  {
    ModelState["YourField"].Errors.Clear(); 
    ModelState.AddModelError("YourField", "Your custom message here");
  }

  // code
}

You can set ResourceClassKey of ClientDataTypeModelValidatorProvider class to name of a global resource that contains FieldMustBeNumeric key to replace mvc validation error message of number with your custom message. Also key of date validation error message is FieldMustBeDate.

ClientDataTypeModelValidatorProvider.ResourceClassKey="MyResources"; // MyResource is my global resource

See here for more details on how to add the MyResources.resx file to your project:

The field must be a number. How to change this message to another language?

To change the error message you get after server side validation you need to change 'PropertyValueInvalid' key in your resource file and assign the resource file name to DefaultModelBinder.ResourceClassKey. See this question for details: localize default model validation in mvc 2

Look for solution at the end of this page:

http://jwwishart.wordpress.com/2010/03/22/custom-server-and-client-side-required-validator-in-mvc-2-using-jquery-validate/

I checked this in my MVC 3 RTM project and it works well.

... or use jQuery to change to message on the client.

A quick and simple hack for Customize RangeValidator ErrorMessage --"'Field name' is not a number"-- is using RegularExpression

[Range(0.5, 1000, ErrorMessage = "Amount should be in range {1} to {2}.")]
[DataType(DataType.Currency)]
[RegularExpression(@"\d", ErrorMessage = "Amount is not valid.")]
public decimal Amount{ get; set; }

You could implement your own custom validation attribute: http://haacked.com/archive/2009/11/19/aspnetmvc2-custom-validation.aspx

It seems that since Para's answer MVC evolved and now the ClientDataTypeModelValidatorProvider accepts a ResourceClassKey property. It uses the FieldMustBeNumeric and FieldMustBeNumeric messages specified in your resource class.