Converting/accessing QueryString values in ASP.NET

Question

I\'m curious what everyone does for handling/abstracting the QueryString in ASP.NET. In some of our web apps I see a lot of this all over the site:

int val = 0;         


        

Answer 1

Here's what I came up with. It uses generics to return a strongly-typed value from the QueryString or an optional default value if the parameter isn't in the QueryString:

/// 

    /// Gets the given querystring parameter as a the specified value 
    /// 
    /// The type to convert the querystring value to
    /// Querystring parameter name
    /// Default value to return if parameter not found
    /// The value as the specified , or the default value if not found
    public static T GetValueFromQueryString(string name, T defaultValue) where T : struct
    {
        if (String.IsNullOrEmpty(name) || HttpContext.Current == null || HttpContext.Current.Request == null)
            return defaultValue;

        try
        {
            return (T)Convert.ChangeType(HttpContext.Current.Request.QueryString[name], typeof(T));
        }
        catch
        {
            return defaultValue;
        }
    }

    /// 

    /// Gets the given querystring parameter as a the specified value 
    /// 
    /// The type to convert the querystring value to
    /// Querystring parameter name
    /// The value as the specified , or the types default value if not found
    public static T GetValueFromQueryString(string name) where T : struct
    {
        return GetValueFromQueryString(name, default(T));
    }

Since writing this post I've written a very small class library for manipulating querystring values - see https://github.com/DanDiplo/QueryString-Helper