Question

I have param “min_payed” in web.config.

And I have model

  public class Pay
    {
        [Required]
        [Range(10,99999999)]
        public Decimal Cost { get; set; }
    }

min value I need get from web.config

Answer 1

You could write a custom range attribute that will read its min and max values from the <appSettings> section of the config file:

public class ConfigBasedRangeAttribute : RangeAttribute
{
    public ConfigBasedRangeAttribute(): 
        base(GetConfigValue("min"), GetConfigValue("max"))
    {
    }

    private static int GetConfigValue(string key)
    {
        return int.Parse(ConfigurationManager.AppSettings["key"]);
    }
}

and then decorate your model with it:

public class Pay
{
    [Required]
    [ConfigBasedRange]
    public Decimal Cost { get; set; }
}