Question

I’m writing a custom serializer for struct types for interop with a protocol I can’t alter. I’m using reflection to pull out structure member values and write them to a BinaryWriter. It’s only designed to support basic types and arrays of them.

if      (fi.FieldType.Name == "Int16")   bw.Write((Int16)fi.GetValue(obj));
else if (fi.FieldType.Name == "UInt16")  bw.Write((UInt16)fi.GetValue(obj));
else if (fi.FieldType.Name == "Int32")   bw.Write((Int32)fi.GetValue(obj));
else if (fi.FieldType.Name == "UInt32")  bw.Write((UInt32)fi.GetValue(obj));
else if (fi.FieldType.Name == "Int64")   bw.Write((Int64)fi.GetValue(obj));
else if (fi.FieldType.Name == "UInt64")  bw.Write((UInt64)fi.GetValue(obj));
else if (fi.FieldType.Name == "Single")  bw.Write((float)fi.GetValue(obj));
else if (fi.FieldType.Name == "Double")  bw.Write((double)fi.GetValue(obj));
else if (fi.FieldType.Name == "Decimal") bw.Write((decimal)fi.GetValue(obj));
else if (fi.FieldType.Name == "Byte")    bw.Write((byte)fi.GetValue(obj));
else if (fi.FieldType.Name == "SByte")   bw.Write((sbyte)fi.GetValue(obj));
else if (fi.FieldType.Name == "String")  bw.Write((string)fi.GetValue(obj));

Obviously this is ugly, and it gets even more ugly when I want to do the same thing with arrays of these types too.

What would be really nice is if I could do something like this:

bw.Write( (fi.FieldType) fi.GetValue(obj) );

Then do a similar kind of thing for arrays.

Any ideas?

Answer 1

You can use reflection to invoke the right version of Write

public static void WriteField(BinaryWriter bw, object obj, FieldInfo fieldInfo)
{
    typeof(BinaryWriter)
        .GetMethod("Write", new Type[] { fieldInfo.FieldType })
        .Invoke(bw, new object[] { fieldInfo.GetValue(obj) });
}