How do you test your Request.QueryString[] variables?

Question

I frequently make use of Request.QueryString[] variables.

In my Page_load I often do things like:

       int id = -1;

             


        

Answer 1

I modified Bryan Watts' answer so that if the param your asking does not exist and you have specified a nullable type it will return null :

public static T GetValue(this NameValueCollection collection, string key)
    {
        if (collection == null)
        {
            return default(T);
        }

        var value = collection[key];

        if (value == null)
        {
           return default(T);
        }

        var type = typeof(T);

        if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
        {
            type = Nullable.GetUnderlyingType(type);
        }

        var converter = TypeDescriptor.GetConverter(type);

        if (!converter.CanConvertTo(value.GetType()))
        {
            return default(T);
        }

        return (T)converter.ConvertTo(value, type);
    }

You can now do this :

Request.QueryString.GetValue(paramName) ?? 10;