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A Generic enum Parser in C#

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May 19, 2011

CPOL
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Generic enum Parser There are many ways to parse an enum . For example, we could use switch in C# to parse enum. But the problem will be if that enum has 10 items in it (for example), then we need to write 10 case statements. So if we have 10 enums with 10 items, then we need to write 10x10 case statements plus all the deafult statements. I use the following technique to parse enum. First of all, I use the following two enums to describe this tip:
public enum EnumOne
{
     None = 0,
     One = 1,
     Two = 2,
     Three = 3
}

public enum EnumTwo
{
     None,
     One,
     Two,
     Three
}
So we could parse the above enum using the following switch code block,
public EnumOne ParseEnum(string item)
{
     switch (item)
     {
       case "One":
         return EnumOne.One;
       case "Two":
         return EnumOne.Two;
       case "Three":
         return EnumOne.Three;
     }
     return EnumOne.None;
}
But we want to parse EnumOne and EnumTwo. As a result, we need to write two blocks of switch, whereas the following generic enum parser will do the job using minimum lines of code.
public TEnum ParseEnum<TEnum>(string item, bool ignorecase = default(bool))
            where TEnum : struct
{
    TEnum tenumResult = default(TEnum);
    return Enum.TryParse<TEnum>(item, ignorecase, out tenumResult) ?
           tenumResult : default(TEnum);
}
To test the above code, we could use the following code block:
public void Test()
{
     Console.WriteLine("{0}, {1}, {2}, {3}, {4}",
           new object[]
           {
              ParseEnum("One"),
              ParseEnum<EnumOne>("Two"),
              ParseEnum<EnumTwo>("TwoTwo"),
              ParseEnum<EnumTwo>("1"),
              ParseEnum<EnumTwo>(string.Empty)
          });
}
In this tip, we assume that whatever enum we are going to parse, it has a default value for example, in here None is default for EnumOne and EnumTwo, otherwise parser will return first item of the enum.