Is there a way to get a type's alias through reflection?

Question

I'm writing a simple code generation application to build POCO's from a DB2 database schema. I know it doesn't matter, but I prefer to use type aliases rather than the actual system type name if they are available, i.e., "int" rather than "Int32." Is there a way using reflection that I can get a type's alias rather than it's the actual type?

//Get the type name
var typeName = column.DataType.Name;

//If column.DataType is, say, Int64, I would like the resulting property generated
//in the POCO to be...

public long LongColumn { get; set; }

//rather than what I get now using the System.Reflection.MemberInfo.Name property:

public Int64 LongColumn { get; set; }

Thanks in advance.

Answer 1

Nope - just create a Dictionary<Type,string> to map all of the types to their aliases. It's a fixed set, so it's not hard to do:

private static readonly Dictionary<Type, string> Aliases =
    new Dictionary<Type, string>()
{
    { typeof(byte), "byte" },
    { typeof(sbyte), "sbyte" },
    { typeof(short), "short" },
    { typeof(ushort), "ushort" },
    { typeof(int), "int" },
    { typeof(uint), "uint" },
    { typeof(long), "long" },
    { typeof(ulong), "ulong" },
    { typeof(float), "float" },
    { typeof(double), "double" },
    { typeof(decimal), "decimal" },
    { typeof(object), "object" }
};

Answer 2

I don't think there is. The alias is completly a compile time concept specific to the paticular .NET language you use. Once you reflect and view the type you will see the true .NET type of the object.

Answer 3

Keep it simple:

var aliasDict = new Dictionary<Type, string>() {
    { typeof(int), "int" },
    { typeof(long), "long" },
    // etc
}

Type reflectedType;
string aliasedTypeName = aliasDict[reflectedType];

Answer 4

This doesn't use reflection, strictly speaking, but you can get to the type's alias by using CodeDOM:

Type t = column.DataType;    // Int64

StringBuilder sb = new StringBuilder();
using (StringWriter sw = new StringWriter(sb))
{
    var expr = new CodeTypeReferenceExpression(t);

    var prov = new CSharpCodeProvider();
    prov.GenerateCodeFromExpression(expr, sw, new CodeGeneratorOptions());
}

Console.WriteLine(sb.ToString());    // long

(Having said that, I think that the other answers suggesting that you just use a mapping from CLR types to C# aliases are probably the best way to go with this one.)