C# – How to make the return type of a method generic

cgenericsnetreturn-type

Is there a way to make this method generic so I can return a string, bool, int, or double? Right now, it's returning a string, but if it's able find "true" or "false" as the configuration value, I'd like to return a bool for example.

    public static string ConfigSetting(string settingName)
    {  
         return ConfigurationManager.AppSettings[settingName];
    }

Best Answer

You need to make it a generic method, like this:

public static T ConfigSetting<T>(string settingName)
{  
    return /* code to convert the setting to T... */
}

But the caller will have to specify the type they expect. You could then potentially use Convert.ChangeType, assuming that all the relevant types are supported:

public static T ConfigSetting<T>(string settingName)
{  
    object value = ConfigurationManager.AppSettings[settingName];
    return (T) Convert.ChangeType(value, typeof(T));
}

I'm not entirely convinced that all this is a good idea, mind you...

Related Solutions

C# – How to calculate someone’s age based on a DateTime type birthday

An easy to understand and simple solution.

// Save today's date.
var today = DateTime.Today;

// Calculate the age.
var age = today.Year - birthdate.Year;

// Go back to the year in which the person was born in case of a leap year
if (birthdate.Date > today.AddYears(-age)) age--;

However, this assumes you are looking for the western idea of the age and not using East Asian reckoning.

C# – Create Generic method constraining T to an Enum

Since Enum Type implements IConvertible interface, a better implementation should be something like this:

public T GetEnumFromString<T>(string value) where T : struct, IConvertible
{
   if (!typeof(T).IsEnum) 
   {
      throw new ArgumentException("T must be an enumerated type");
   }

   //...
}

This will still permit passing of value types implementing IConvertible. The chances are rare though.

Best Answer

Related Solutions

C# – How to calculate someone’s age based on a DateTime type birthday

C# – Create Generic method constraining T to an Enum

Related Topic