CODEWITHSUNDEEP
c#serializationxnabinaryfilesbinaryreader
Pectus Excavatum
Pectus Excavatum

Reputation: 3783

c# - how to best save and load an enum

I am trying to serialize an enum object within a class. Currently I am going to be using a binary reader and writer to serialize/de-serialize.

My enum is called SelectionType and has a few possible values.

In my serialize method I write the toString value of the enum object I want to save.

I then dont know what to do with the string to turn this back into an enum when I read the string. I dont really want to have a hard coded case for each possible value.

I basically want to say; SelectionType newenumobject = SelectionType.String // where string is the value read from the file.

ANy help would be greatly appreciated:

here is what I have:

        public override void Serialize(Stream stream)
    {
        System.Diagnostics.Debug.WriteLine("in level select serialize");

        using (BinaryWriter writer = new BinaryWriter(stream))
        {

            //Debug.WriteLine("the type is" + SelectionType.ToString());
            writer.Write(SelectionType.ToString());


            // Write out the full name of all the types in our stack so we can
            // recreate them if needed.
            //byte[] bytes = new byte[SelectionType.ToString().Length * sizeof(char)];
            //System.BitConverter.GetBytes(mSlectionType);
            //writer.Write(bytes, 0, bytes.Length);
        }
    }



    public override void Deserialize(Stream stream)
    {
        using (BinaryReader reader = new BinaryReader(stream))
        {

            while (reader.BaseStream.Position < reader.BaseStream.Length)
            {
                // read a line from our file
                string line = reader.ReadString();

                // if it isn't blank, we can create a screen from it
                if (!string.IsNullOrEmpty(line))
                {

                    Debug.WriteLine("line is" + line);

                    Type screenType = Type.GetType(line);
                    //SelectionType selection = Enum.Parse(screenType, line, false);
                }
            }

           // char[] chars = new char[bytes.Length / sizeof(char)];
            //System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
            //new string(chars);

        }

Upvotes: 1

Views: 5303

Answers (3)

BMac
BMac

Reputation: 473

If you care about file size and read/write speed, you should save the underlying value of the enumeration rather than converting it to a string.

// be sure to use the correct backing type for your enum (default is 32-bit int)
writer.Write((int)SelectionType);

//...

selection = (SelectionType)reader.ReadInt32()

Upvotes: 3

Chris
Chris

Reputation: 326

You can just use Enum.Parse. Here is an example: http://dotnetfiddle.net/0e1Ika

    var myValue = MyEnum.Value3;

    var stringRepresentation = myValue.ToString();
    var intRepresentation = (int)myValue;

    Console.WriteLine("String-Value: \"{0}\"", stringRepresentation);
    Console.WriteLine("Int-Value: {0}", intRepresentation);

    var parsedFromString = (MyEnum)Enum.Parse(typeof(MyEnum), stringRepresentation);
    var parsedFromInt = (MyEnum)Enum.Parse(typeof(MyEnum), intRepresentation.ToString());

    Console.WriteLine("Parsed from string: {0}", parsedFromString);
    Console.WriteLine("Parsed from int: {0}", parsedFromInt);

Hope that helps.

Best regards, Chris

ps: uh, seems @dave-bish was faster :)

Upvotes: 2

Dave Bish
Dave Bish

Reputation: 19646

if you know the type of the enum, you can use Enum.Parse

var myValue = (EnumType)Enum.Parse(typeof(EnumType), "StringValue");

[Edit] I see you have it commented out in your example - Why didn't this work for you?

Upvotes: 0

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